title: What is positional play in chess?

text:
# Question
Title: What is positional play in chess?
I have played chess so many times, understood tactics (pins, discovered check, overloading, deflection, skewer), but I never understood clearly the positional play. I have noticed not many tutorials available that explains positional play.

1. What exactly is positional play? Why is it important?
2. Please can you show some nice examples to understand the concept?

Sorry for being so naive, but very curious on this.

# Answer
Classically positional play is what is described in part 2 of Nimzowitsch's "My System". Part 1, The Elements, is more tactical in nature. It describes play in open files, using the 7th and 8th ranks, passed pawns, pins, discovered checks and a few other features.

Part 2, Position Play, deals with stuff like

1. Fighting for the center, which you do by moving pawns and pieces (firstly knights and bishops, later rooks) so that they occupy, support or attack the center.
2. Over protection of important points or squares, in the first instance central ones later they may be points important for attack or defence, is important because it strengthens those points. This in turn gives more freedom and flexibility to the pieces involved. They are not firmly tied down because other pieces are sharing the burden. And it gives prophylaxis. Because these points are over protected you are not going to get caught by a sudden attack from your opponent.
3. Certain static features are described and discussed which have positional characteristics. Doubled and isolated pawns are usually positional weaknesses. Very occasionally they may have good features but mostly they are bad. The IQP (isolated queen's pawn) is covered in great depth. Depending on how the two sides play the IQP can be a dynamic attacking tool or it can be a static weakness which will eventually fall.
4. The two bishops (when you have two bishops and your opponent has either two knights or one bishop and one knight) is positional plus because of the way they can work together. They can cut an impassable diagonal line across the board in the same way that a rook can cut such lines orthogonally.

Why are these concepts important? Well, when you first start playing you don't really know what to do with your pieces. As Nimzowitsch says you probably think you should get your pieces out, castle on the opposite to your opponent and then each of you should launch a pawn storm attack against your opponent's castled king. First one to break through wins. It can certainly be a lot of fun but it's just not going to work against somebody who has mastered a more positional way of playing.

These positional concepts give you guidelines of how to play when the position doesn't call for a tactical solution. In some respects it gives you guidance of how to build up your position so that you can either start your own tactical attack or frustrate your opponent's tactical attack.

Mastering tactical and positional play will likely take you to somewhere round about the 2000 level, which is no mean feat. To make progress much beyond this level you will have to start to learn and understand when to break these positional guidelines.

My System has many examples and games which Nimzowitsch uses to illustrate his points. He also wrote a follow on book of more examples and games called Chess Praxis which is highly recommended for further study of positional play.
> 15 votes

# Answer
Positional play is the attempt to make make a small improvement in your position with every move. In the most simplistic sense this would involve making your worst piece more active, bringing pressure to bear on an important square, improving pawn structure or denying your opponent the opportunity to improve his position.

If you watch a chess engine working you can see and feel how it accumulates a positional advantage with almost every move. It feels like being slowly strangled. Tactics emerge naturally from a strong positional advantage. I would often spend far too long looking for tactics before the position warranted it. Now I may sense the possibility of tactics but be unclear of the outcome. Often all that's needed to make a tactic work is making one more strong positional move.
> 5 votes

# Answer
Tactics is the science of piece safety. Positional play is play involving 'piece activity' and 'pawn structure'.

If you are rated under 1300, positional play is not important because tactical advantages (material) are much greater than positional advantages (slightly better pawn structure). Once you reach 1500, however, positional play becomes every important because it is how games are won and lost, once players stop giving free pieces and pawns.
> 3 votes

# Answer
Positional play is maneuvering for small advantages, like controlling the center with pieces and pawns, gradually improving your position and encroaching into enemy territory to gain a space advantage while at the same time minimizing your opponent's space and opportunities until you can utilize tactics for some kind of decisive result. I like to use Nimzovitsch's term prophylaxis for this, limiting your opponent's moves. The closed openings, like the Queens's Gambit, are generally considered positional openings since the pieces don't come into contact with each other so soon as opposed to double king pawn openings, or open games, when early tactics can predominate. If you want concrete examples, in addition to looking at Nimzovitch's games, the orthodox advice is to "study the games of Capablanca, Smyslov and Karpov". You can find these on chessgames.com.
> 2 votes

# Answer
**In the absence of any tactical justification,** it is logical to:

1. Put your knight on e4 rather than on a1 because on e4 your knight would have much more influence on the game (it controls 8 squares) than on a1 where it controls only 2 squares.
2. Put your bishops on open diagonals, your rooks on open files, 7th rank... etc thus they will have maximum activity
3. Keep your pawns connected as long as possible because they are very simple targets for attacks when they are isolated, doubled... etc.

This system of thinking is in fact the root of positional play and you can see it in action when studying Capablanca games.

I recommend also Igor Smirnov's course "Grandmaster positional understanding".
> 2 votes

# Answer
There are many aspects of positional play that are always mentioned. Put Rooks on open files, put knights on outpost squares, keep your pawns neat and tidy. But that is not enough to win if your opponent shows similar good sense.

A very important aspect of positional play is knowing which of your pieces to exchange and which to keep. Sometimes this leads to decisions that seem contradictory. Elizabeth Pahtz does a nice DVD on this topic for Chessbase and you can get a free preview by going to this article on the Chessbase site.

In this she shows a very instructive game Smyslov-Reshevsky where making the favorable exchange is more important than preserving the pawn structure. Positional play is not always risk-free play.
> 1 votes

# Answer
Positional play is when you gradually outplay your opponent. For example, if you manage to win a pawn and manage to realize that small advantage into a win. Usually players who like positional play (opposite to tactical players) are very patient players who prefer positional openings. It needs to be said that the openings are the very important indicator whether this game is going to a positional game or tactical. For example, Queens Gambit is a positional opening.
> 0 votes

# Answer
Basically positional chess is everything that isn't tactical. Open lines, outposts, pawn structure, piece activity, and many others are examples.

```

[fen ""]

[White "2000"]
[Black "2000"]
[Result "1-0"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Nxc6 bxc6 6. Qd4 Nf6 7. e5 Qa5+ 8.
Qc3 Qxc3+ 9. Nxc3 Nd5 10. Nxd5 cxd5 11. Be3 Bg7 12. O-O-O Bxe5 13. Rxd5 d6 14.
Bb5+ Bd7 15. Rhd1 Bxb5 16. Rxb5 {White has more active pieces and open files.
 The real weakness is that a7 can't be protected well.  Now black makes a
tactical mistake.} 16... O-O 17. c3 a6 18. Rb7 e6 19. f4 Bg7 20. Rxd6 Bh6 21.
Kd2 a5 22. Ke2 a4 23. Rdd7 {Due to the doubled rooks on the seventh, black can
never activate his pieces.} 23... a3 24. b3 Rac8 25. c4 {Now black's bishop has
nothing to attack on the queenside and is biting on granite on the kingside.}
25... Bg7 26. Bd4 Bh6 {Although white's bishop is better, every trade brings
white closer to a won endgame.} 27. Kf3 Rfd8 28. Bf6 Rxd7 29. Rxd7 Bf8 30. Rd8
Rxd8 31. Bxd8 *

```

```

[FEN ""]
[White "2000"]
[Black "2000"]
[Result "0-1"]

1. d4 e5 2. e4 exd4 3. Nf3 Nc6 4. c3 d3 5. Bxd3 d6 6. O-O Be7 7. Be3 Nf6 8. h3
O-O 9. Nbd2 Re8 10. Qc2 h6 11. Rfe1 Bf8 12. Nd4 Ne5 13. Bf1 c5 14. Nf5 {Nb3 to
stop black from playing d5 is the correct move.} 14... d5 15. f4 Bxf5 16. exf5
Nc6 17. Nf3 Qc7 18. Bd3 {Black controls more of the center and white's king side
is weakened, but white has everything protected.  Is there a combination?} 18...
c4 19. Bf1 Rxe3 {The weakness of the dark squares allows black a vicious
attack.} 20. Rxe3 Bc5 21. Qd2 Qxf4 22. Nd4 Nxd4 23. Kh1 Ne4 *

```

These games, played by 2000 rated players, show some of the positional elements and how to exploit them.

They aren't the best, but the first ones I thought would show some themes.

EDIT: http://www.chessgames.com/perl/chessgame?gid=1012733 and http://www.chessgames.com/perl/chessgame?gid=1012683 are nice examples of Alekhine using positional elements.
> 0 votes

# Answer
Positional play: positioning ( Bring ) ur pieces into the contact of strategically important squares . Ok then what is strategically important squares? Strategy: plan of action designed to achieve overall goal Goal: checkmate?? In reality chess is drawish game( it's impossible to checkmate if both side play correctly cause it's like war between the countries with equal force) Ok then what's our goal then only we can design the plan?! Goal: activity (positive action for the pieces)ex 1.e4 e5 2.nf3 Every one follows with nf3 cause it limits opponents response and ur +ve action n\*e5 conclusion : goal :activity strategy : bring ur pieces to the squares that will give greater activity ( central squares, blockading squares,holes in ur opponent camp).U should overprotect that squares with all of ur pieces ...it will give greater activity for ur pieces..... Simple idea but strong: overprotection!!! In the fight for the strategically important squares .ex : fight for the e5 square if the square control count is 5vs4 then U can move any of ur 5 pieces greater activity!! But 4vs4 ur pieces are tied to that great squares but ur pieces are tied....
> -2 votes

---
Tags: strategy, positional-play
---


title: Most drawish and least drawish opening

text:
# Question
Title: Most drawish and least drawish opening
Based on statistics (drawing percentage), which opening is the most drawish and which one is the least drawish? I am aware of questions such as this one, but my question is different.

There are two criteria.

1. It must be played by professionals.
2. It must not be an intentional loss (no hanging pieces, etc., so your opponent wins instead of drawing) for either side.

# Answer
Dana Mackenzie wrote a nice series of articles about opening statistics in 2015.

For the most drawish openings, he writes this:

> The Exchange Slav (D14) dominates this category like no variation dominates any other category. It’s a unique ECO code, a variation that is more about the players’ psychology than about chess. According to Rob Weir’s tables, this variation results in a draw 79.9 percent of the time in master play, and usually quickly. (The average number of moves is 25, about 8 less than any other variation.) If anything, I think that Weir’s statistics understate the extent to which these six moves serve as a wordless draw proposal. Weir removed all games of 10 moves or shorter from his database. When I look this position up on ChessBase, it looks as if at least 90 percent of the games are draws.
>
> The top five drawing variations:
>
> D14 (Exchange Slav with … Nc6 and …Bf5): 79.9 percent draws
>
> D79 (Symmetric Grunfeld, 1. d4 Nf6 2. c4 g6 3. g3 d5 4. Bg2 Bg7 5. Nf3 O-O 6. O-O c6 7. cd cd): 59.0
>
> C92 (Ruy Lopez, Flohr-Zaitsev Variation 9. … Bb7): 57.5
>
> D13 (Exchange Slav, not 5. Nc3 Nc6 6. Bf4 Bf5): 56.2
>
> B36 (Maroczy Bind, side variations): 56.1

For the least drawish:

> Unlike the last category, the Hall of Shame of chess openings, this category consists of the most honorable, “fightingest” opening variations in chess. And what better variation to start with than B89, the Velimirovic Attack in the Fischer-Sozin Variation of the Sicilian Defense? The above position arises after 1. e4 c5 2. Nf3 d6 3. d4 cd 4. Nxd4 Nf6 5. Nc3 e6 6. Bc4 Nc6 7. Be3 Be7. To get an idea of the fireworks that may ensue, take a look at the amazing game Fischer-Geller from Skopje 1967. This was one of the three losses that Fischer included in his My 60 Memorable Games, so you know it has to be a pretty special game.
>
> The top five:
>
> B89 (Sicilian Defense, Sozin-Fischer-Velimirovic Attack): 25.2 percent draws
>
> A44 (Old Benoni, 1. d4 c5 2. d5 e5): 25.5
>
> B00 (Uncommon 1. e4 openings, e.g. Nimzovich 1. … Nc6, Borg 1. … g5, etc.): 27.5
>
> C05 (French Tarrasch, closed variation, including the pawn sac 1. e4 e6 2. d4 d5 3. Nd2 Nf6 4. e5 Nfd7 5. Bd3 c5 6. c3 Nc6 7. Ngf3 Qb6 8. O-O!?): 29.5
>
> A60 (Main Variation Benoni, 1. d4 Nf6 2. c4 c5 3. d5 e6, side lines): 29.6
> 8 votes

---
Tags: opening, draw, statistics
---


title: What to do after losing a game?

text:
# Question
Title: What to do after losing a game?
> What to do after losing a game?

I think that this question is on everyones' minds after a loss. I am guessing that everyone has their own way of coping with a loss. The best way to cope with a loss can turn out to vary from person to person. Yet, I think that it should be possible to find some sort of "best practice" procedure to draw wisdom from a loss and cope with it in a productive manner. Most chess players I know, including myself, feel terrible after a loss. One of the first negative thoughts that arises is

> What is the point? I trained and competed so much and I still lost!

Today, I know that there are (at least) three ways of losing a game.

1. Become completely outplayed with virtually no counterplay.
2. Blunder (e.g. during time trouble).
3. Enter a position with chances for both sides, do your best and still lose.

It is clear that whatever level of skill you have, you can still lose. So what to do afterwards? Is there a **best practice**?

# Answer
> 13 votes
The best practice would be to thoroughly analyze the *game* and also your *thought process* before, during and after the game. Besides, if after sincere hard efforts you still lose, it's important to have an attitude like this -

> “I haven't failed, I've found 10,000 ways that don't work” - Thomas Edison

In chess, that would mean -

> I haven't failed, I have discovered that this strategy/opening/tactic/etc. doesn't work.

In my personal experience, you often learn more from the games you lose than from the games you win. So use that to your advantage. Analyze the game thoroughly (of course with the help of an engine) and see where you went wrong. Also, identify faulty patterns of thinking during the game. For example -

> "this position was objectively equal, but during the game I thought I was worse and so I got *demotivated* and played badly".

Gary Kasparov suggested the following after winning (but I suppose it applies all the more after losing) -

> "Even the game we won always contained mistakes; inaccuracies. It's inevitable. I can hardly find one brilliant game with no mistakes."
>
> "If we won, it is most likely because our opponent made the *last* mistake. But, he made the last mistake and he is definitely analyzing the game; he'll find what we did wrong in the previous stage of the game. So what is important is to find it first."

I found some other interesting quotes on this page. Some of the more interesting quotes are -

> Losing can persuade you to change what doesn't need to be changed, and winning can convince you everything is fine even if you are on the brink of disaster. - Garry Kasparov
>
> Don't be afraid of losing, be afraid of playing a game and not learning something. - Dan Heisman
>
> I prefer to lose a really good game than to win a bad one. - David Levy
>
> Setbacks and losses are both inevitable and essential if you're going to improve and become a good, even great, competitor. The art is in avoiding catastrophic losses in the key battles. - Garry Kasparov
>
> You may learn much more from a game you lose than from a game you win. You will have to lose hundreds of games before becoming a good player. \- Jose Capablanca
>
> Most players ... do not like losing, and consider defeat as something shameful. This is a wrong attitude. Those who wish to perfect themselves must regard their losses as lessons and learn from them what sorts of things to avoid in the future. - Jose Capablanca

# Answer
> 13 votes
Don't forget to be a good sport. Smile, shake hands with the winner, and congratulate them on a good game. Then later, when you've calmed down, when you're in a more focused frame of mind, analyze your game. (Keep a notebook of the moves).

1) Look for obvious blunders - hanging pieces, bad trades

2) Look for tactical mistakes - forks, pins, etc.

3) Look for strategic mistakes - pieces becoming cramped, weak pawn structure.

4) Decide if one section of the game gave you more trouble than others. (Opening, middle, endgame)

5) Create your practice plan. Review topics that gave you trouble. Do some practice puzzles. Play against yourself. Play against a computer.

More tips:

* Practice focusing on only the board, shut everything else out. Getting angry, sad, or even happy during a game can make you lose focus.
* Don't pay attention to your opponent. Just play against the board. Don't rely on him to make mistakes, or move in a certain way. Assume that every move he makes will be the best one he can, and you do the same. If you know what his best move is, and he makes a different one, that's a clue that you have an opportunity to gain an advantage.
* Ultimately, a lot of openings in chess will result in black losing, if both players play perfectly. It might not be your fault, just that black starts off one tempo behind. Play both sides, often.

# Answer
> 3 votes
Embrace **improving** at chess. Make it your primary goal. Get set in your mind that winning is secondary.

Take action on the new goal. **Analyze all your games**. Analyze with your opponent whenever possible. Try to play longer games you can record, and leave blitz for online play (where the computer records your games)

Take some time before you resign to get your mind straight, so you can be a good sport.

If rating is important to you, recognize that rating is a trailing indicator. Rating will rise as you get better. Rating goes up with wins and down with losses, but it will not reliably increase without becoming a stronger player.

# Answer
> 2 votes
World champion Jose Raul Capablanca once said, "From few of my won games have I learned as much as most of my losses."

So look upon a lost game as learning experience. They're usually easier to remember than your wins. To this day, I remember how someone beat me forty years ago with a $450 hotel on Baltic avenue because I had mortgaged everything getting both the green and the maroon monopolies. (All right, that's a different game, but you get the point.) Because the lost games are easy to remember, it's also easy to identify, and hopefully correct your mistakes. (The hardest mistakes to identify are those that should have cost you the game, but didn't.)

In Capablanca's case, most of his lost games came from making the wrong decision at a critical turning point. He even saw the fork in the road ahead of time, but lost his caution when it was time to pull the trigger. Ultimately, his opponent's threats were larger than they seemed at the time, and he lost by misjudging them. When he went back, he worked through how the better choice could have allowed him to draw, or even win the game. That made him good at making the "better choice" in the future.

# Answer
> 0 votes
Analyze and find out why you'd lost the game. It might probably be the cause of a simple blunder or just a small mistake. In each case, find out exactly what went wrong, whether it's time pressure or other factors.

# Answer
> 0 votes
What you should do particularly when you have just lost to a stronger player is ask them if they will go over the game with you. This normally means going to a separate room if you are playing a tournament but I have had strong players silently play over a few variations showing me where I went wrong without attracting the ire of the arbiters. The "silent" part, though, is vital and if you actually want to discus the game you will have to go to the analysis room or get thrown out.

Losing to much stronger players and having them analyze with you afterwards is absolutely invaluable. I have learned a lot this way. You should take every chance you get to do this.

# Answer
> 0 votes
I humbly believe the best way to learn chess is to learn from lost games. Analyse *all* your games, especially those that were not successful. - You will learn a lot from own mistakes, and you will most likely remember that "breaking point" when you enounter it again, and think "no, I will not fall for that again".

# Answer
> 0 votes
I do not necessarily endorse this opinion, but I once heard an IM say, that for amateurs, excessively analysing lost games can be counterproductive. Amateurs make so many mistakes even in won games, that they will learn just as much from analysing won or drawn games. The difference is that this will be much more enjoyable. And wallowing in misery is probably not the ideal mindset to learn and improve.

My take on this is, that you should definitely analyse lost games, if the way you lost, or the opening or type of position you lost in, is typical for you. Otherwise it might often be better to just let it go. If you made a bad blunder, beating yourself up about it, will not make you a better player. On the contrary, it might just wreck the necessary confidence to play well.

# Answer
> 0 votes
With regard to Blindkungfumaster’s comment, I agree that over analyzing losses as a novice might be counterproductive. Sometimes the reasons for losing the game are so obvious that analysis is unnecessary. Such as leaving pieces hanging, which I do!

---
Tags: psychology, losing, best-practice
---


title: Where can I find a good chess database?

text:
# Question
Title: Where can I find a good chess database?
What is the best chess database out there (quality vs. price). Do you recommend online or offline chess database. Any experience with chessbase, chessok, chesstempo or openingmaster?

# Answer
> 3 votes
The TWIC (This Week In Chess) database is your best bet. It's free, has millions of games (many of which are recent and up to date), and is of a high quality.

Here's the link: http://theweekinchess.com/twic

When you get there, scroll down to the "TWIC Downloads" table and download all the PGN or all the CBV files.

After downloading everything, merge all the games into one database in ChessBase.

Then, you can make this database your reference database (if you don't know how to do this, look up a YouTube tutorial on ChessBase's official channel).

# Answer
> 1 votes
I find that https://365chess.com has an AMAZING range of games - it's the only place I've been able to find some really old games. For basic analysis, I use the https://lichess.org analysis board because the overall experience on the site is so great. Seriously. It's amazing.

# Answer
> 0 votes
openingmaster.com with 26 millions is the biggest chess database with zero duplicates. Smaller 8 mil is OTB and 1,7 mil is Correspondence chess database. All you need is there.

---
Tags: opening, database, online
---


# Question
Title: what is the shortest allowable time control for a FIDE rated standard tournament game?
My chess club wants to host a FIDE tournament in a couple of months with 3 FIDE rated games in one day.

What is the shortest allowed time control for FIDE rated standard tournament games so we can fit in all 3 games on one day? Thanks!

Best, Richard

# Answer
According to the FIDE Rating Regulations, it depends on the player ratings:

> 1.1 For a game to be rated each player must have the following minimum periods in which to complete all the moves, assuming the game lasts 60 moves.
> Where at least one of the players in the game has a rating 2200 or higher, each player must have a minimum of 120 minutes.
> Where at least one of the players in the game has a rating 1600 or higher, each player must have a minimum of 90 minutes.
> Where both of the players in the game are rated below 1600, each player must have a minimum of 60 minutes.
>
> 1.2 Where a certain number of moves is specified in the first time control, it shall be 40 moves.
> 6 votes

---
Tags: fide, time-control
---


# Question
Title: Why does AlphaZero evaluate on the order of 1000 times less moves than Stockfish?
According to Deep mind's article, Alpha Zero searches roughly 10,000 moves per decision, while Stockfish is around 10,000,000 moves. I'm aware that Alpha Zero uses Monte Carlo Tree Search while Stockfish uses minimax, but why would this cause 1000 times less moves to be considered?

# Answer
> 4 votes
Very simple. Running a large neural network with floating numbers can’t be quicker than running a simple C++ function on integers.

AI machine learning is not new to chess. There were serious attempts before Google established. Unfortunately, nobody had the determination, skills and resources to do a good job. Nobody wanted to invest money. Before Google's chess journey, the chess engine community believed:

> AI chess will not beat classical programming because neural networks (or other models) run much slower.

# Answer
> 0 votes
While I was in the middle of writing this question I came up with a probable answer, so I'll write it here. AlphaZero is actually running through the same positions *far more* than 10,000 times, it's just doing it on a set of positions roughly 10,000 large. So each position has many playouts run on it, each \>= in length than the last.

Stockfish looks at millions of positions and evaluates each only once (not taking things like iterative deepening search into account). Meanwhile, AlphaZero repeatedly looks at promising branches based off their previous preformance. This explains why it only looks at 10,000 moves, since it's usually only sampling the best it can find.

# Answer
> -1 votes
Because alphazero's evaluation algorithm is far more complex and takes up way more computing power than normal chess engines evaluation algorithm.

In fact if you were to fairly compute how much processing power each engine uses, no doubt alphazero takes up way more power to beat normal engines.

---
Tags: engines, stockfish, calculation, alphazero
---


# Question
Title: Lichess Puzzle 82753: Can white win with a queen and two pawns vs. rook and four pawns?
Lichess puzzle 82753 involves a rook and pawn endgame where white sacrifices their rook to queen a pawn. The final position is the following (with black to move):

```
[FEN "2Q5/6p1/1K3pkp/8/8/4p3/r5PP/8 b - - 0 44"]

```

I'm not convinced white can win from here; it looks like black can swap off one pair of pawns, then set up a fortress. This seems to hold on against Lichess’s version of Stockfish, but I don't think it looks especially deep. Maybe there's a winning strategy for white, though, that it didn't find.

*Question*: Can white win with a queen and two pawns vs. rook and four pawns?

# Answer
It looks very difficult for white to prevent the fortress.

The obvious sequence is something like -

```
[FEN "2Q5/6p1/1K3pkp/8/8/4p3/r5PP/8 b - - 0 1"]

1... Rb2+ {to kick the king one square further from the action} 2. Ka5 Rxg2 3. Qe8+ Kh7 4. Qe4+ Rg6 5. h4 (5. Qf5 h5 {if Qf5 then h5 anyway} 6. Qxh5 Rh6 {when Qxh5 it leaves white struggling to save the h pawn}) h5 {and black has 3 extra pawns, albeit the e3 pawn is likely to fall soon}

```
> 7 votes

# Answer
I think it's a draw. Don't have an access to an engine right now though 1... Rxg2 2. Qe8+ Kf5 if 3.Qxe3 Rxh2 I don't see a way to win black's rook immediately. Even if black can't capture the h2 pawn it doesn't seem that difficult for him to regroup and set up a fortress. 3. Qh5+ Rg5 leads to an immediate draw.

Missed that after Kh7 black can block Qe4+ with Rg6 as given by Brian. That variation is completely drawn.
> 2 votes

---
Tags: analysis, endgame, puzzles
---


# Question
Title: Can one win with two dark square bishops and two light square bishops and his opponent has only one queen?
Can one win with two dark square bishops and two light square bishops and his opponent has only one queen?

I remember seeing this endgame being analyzed in a video around 10 years ago (and I think the answer is yes) but could not find the video any more.

# Answer
What you're referring to is a so-called "7-man" ending (2 kings, 1 queen and 4 bishops). Luckily for you, we have 7-man tablebases which are even available online and which allow us to analyze every possible legal 7-man chess ending.

```
[FEN "1q1k4/8/8/8/B7/1B6/1B6/2B1K3 w - - 0 1"]

```

Randomly setting up the above position shows that white is indeed winning, and generally most positions seem to show white winning. However, this isn't always the case, for example the following is a draw (white to move) because of the fact that black can either fork the king and one of the bishops, or can fork two bishops:

```
[FEN "3k3K/B3q3/8/8/8/8/B7/2B4B w - - 0 1"]

```

The tablebase also shows how the win often doesn't require that many ply, depending on the starting position of course.
> 5 votes

---
Tags: endgame, queens, bishops, bishop-pair
---


# Question
Title: Can GMs use computers to beat their opponents?
For example, suppose it's game 12 of the Carlsen-Caruana match last year. Caruana has white, and he wants to win before the tiebreaks. Now if instead of Caruana playing white, Stockfish were playing, one can practically guarantee that Stockfish will win the game. Therefore, in principle, Caruana can also win the game, regardless of what opening line Carlsen chooses.

So Caruana can pick an opening by inputting what Carlsen is likely to play to Stockfish. For example, suppose Stockfish plays 1.d4 and Carlsen is likely to respond with 1...Nf6. Caruana can give that to Stockfish and see what Stockfish comes up with. Regardless of what line Carlsen chooses, Stockfish should be able to reach a line that has winning chances. In the same way, this technique would beat well-known drawing lines such as the Petroff or the Berlin. This technique would even work to achieve a win with black, since Stockfish is also very likely to beat Carlsen with black.

Questions: does this scheme work? If so, do human GMs already use it? If so, why aren't GMs aiming to win with black as well as with white?

# Answer
> 5 votes
You pretty much described modern day preparation...

This is exactly what GMs are doing, except that they also try to add some of their own creativity into the process. Nevertheless, the majority of the heavy lifting is done by engines.

However, the process doesn't come close to guaranteeing a win due to the sheer number of possibilities. For example, assume that on each of your opponent's moves, he has 3 good moves to choose from. This means:

* After his 1st move, you have to prepare for 3 outcomes.
* After his 2nd move, you have to prepare for 9 outcomes (since each of the 3 outcomes for his 1st move then have 3 follow up outcomes when its his turn on the 2nd move).
* After his 3rd move, you have to prepare for 27 outcomes.
* 4th move ==\> 81 outcomes.
* 5th move ==\> 243 outcomes.
* 6th move ==\> 729 outcomes.
* 7th move ==\> 2187 outcomes.

You can see where this is going, and this is based on the generous assumption that your opponent only has 3 acceptable choices. After the early stages of the opening, this number is often much higher.

But going off 3 choices, the horrible function for the approx. number of reasonable outcomes is f(x) = 3^x, where x is number of moves your opponent has made. However, GMs often still manage to prepare for 20 moves, which means their opponent has moved 10 times. 3^10 = 59,049. So GMs are clearly very clever at predicting what's going to happen, and have excellent memories, but even this can barely get to 20 moves.

# Answer
> 4 votes
Doesn’t make sense to me. Stockfish even running on a super computer will not be able refute an established opening. Furthermore, the other side can do the same preparation.

It’s not as simple as that. You can’t just memorise by heart engine lines and hope to win. You don’t have memory to hold all the possible lines.

# Answer
> 2 votes
That a human uses engine techniques to beat their opponent is practically impossible. Even if the human has an excellent understanding of all of the evaluation techniques used by the engine, the human would never be able to prune all lines as perfect as the engine.

The human is a human, while the engine is a silicon brain. Engines do win drawish openings against humans because they can punish every small inaccuracy made by the human. The human can never do this. If he/she does so, he/she will be making their own mistakes, and pressing for a win in such scenario is likely to result in a loss.

In your example, Caruana can only win the game if he can play a perfect game and penalise every mistake Carlsen makes. Otherwise, his only chance is to be the second-to-last to make a mistake, which he won't likely be able to achieve intentionally.

# Answer
> 1 votes
1. Yes it works against unprepared opponents to get a superior position.
2. Yes, most super-gms use engine prep for certain must win scenarios.
3. Because both sides are using engine prep and white inherently has an advantage to being with.

In fact in the previous WCC, most advantages came from engine use exclusively.

---
Tags: opening, engines, preparation
---


title: How bad is the Elephant Gambit?

text:
# Question
Title: How bad is the Elephant Gambit?
I tend to think the Elephant Gambit is dubious, but what is the best path to a White advantage?

```
[fen ""]
1.e4 e5 2.Nf3 d5

```

**Update**: RemcoGerlich's comment of an upcoming book is quite relevant! Typical analysis is only 4 moves deep claiming White is better (as shown in some answers below).

I had never seen 1.e4 e5 2.Nf3 d5 3.exd5 **Bd6** given as "Elephant Gambit Proper" on wikipedia (link in Kortchnoi's answer); The wiki, by-the-way, quotes De Firmian analysis which is pre-computer analysis.

# Answer
> 2 votes
Good question. You are right, the Elephant gambit appears to be a dubious opening. Have you checked the wikipedia page on the Elephant Gambit? It offers good lines to fight for an advantage. But they are two other questions:

1. Do you like to defend or retain the initiative?

Those playing this opening are not afraid to gambit a pawn for the initiative with 1.e4 e5 2. Nf3 d5 3.exd5 e4. In most of the lines following 4.Qe2 Nf6 5.d3 Be7 or 4.Qe2 Nf6 5.Nc3 Be7 white has a pawn up but black has the initiative. With a precise play and a bit of patience, white will gain an advantage.

2. Do you like opening theory?

The issue is that you are going to face this rare opening once or twice in your tournament life and most of the time black will be better prepared (in this rare line). He/she will have more experience with this gambit. So, another way to deal with this gambit will be to go for an unrated variant such as

**1.e4 e5 2. Nf3 d5 3.Nxe5 Bd6 4.d4 dxe4 5.Qe2!?**

```
[fen "rnbqk1nr/ppp2ppp/3b4/4N3/3Pp3/8/PPP1QPPP/RNB1KB1R w KQkq - 0 1"]

```

**followed by Nc3, Bg5 and 0-0-0...**

Those continuations have many advantages: Easy to remember; easy to play, and maybe not the kind of positions black are looking for when playing the Elephant Gambit !

# Answer
> 1 votes
Edit:

```
[fen ""]
1. e4 e5 2. Nf3 d5 3. exd5 e4 4. Qe2 Nf6 5. Nc3 Be7 6. Nxe4 O-O 7. Nxf6+ Bxf6 8. d4 Qxd5

```

is more of what the OP is looking for. In this case 4.Qe2 shuts down black's pressure placed on the f3 knight. He can't defend the pawn on e4 and remove the pin in time to do anything with the pawn.

---
Tags: opening
---


# Question
Title: Why can't I use my stockfish engine with python chess?
I'm using python chess and I'm trying to use my stockfish 10 engine downloaded from the stockfish website.

```
import chess.uci

engine = chess.uci.popen_engine(r"stockfish-10-linux/Linux/stockfish_10_x64")

```

Leads to the error:

```
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/tim/anaconda3/lib/python3.7/site-packages/chess/uci.py", line 1139, in popen_engine
    return _popen_engine(command, engine_cls, setpgrp, **kwargs)
  File "/home/tim/anaconda3/lib/python3.7/site-packages/chess/_engine.py", line 295, in _popen_engine
    PopenProcess(engine, command, **popen_args)
  File "/home/tim/anaconda3/lib/python3.7/site-packages/chess/_engine.py", line 133, in __init__
    self.process = subprocess.Popen(command, **popen_args)
  File "/home/tim/anaconda3/lib/python3.7/subprocess.py", line 756, in __init__
    restore_signals, start_new_session)
  File "/home/tim/anaconda3/lib/python3.7/subprocess.py", line 1499, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
PermissionError: [Errno 13] Permission denied: 'stockfish-10-linux/Linux/stockfish_10_x64'

```

I've done this before on my old computer and I'm mimicking my old code which ran with no problem. Except in my old code I used stockfish 9 and here I'm using stockfish 10. Also I imported chess.engine in my old code but now it says this library isn't available.

# Answer
In the error log you've pasted you can see it's a permission error, which can occur for files that behave as "executables" if you will (think any form of program, e.g. scripts, compiled files etc), but that have not been given the rights by the os to do so. One way to fix it, go to the folder containing the engine file and open a terminal to run the following command which will render your file as executable to the os:

`chmod +x stockfish_10_x64`

Alternatively, right click, go to properties, permissions and select "allow executing file as program". After this (by either method) you should be able to load and run the engine within the python-chess library.
> 4 votes

---
Tags: engines, software, python
---


# Question
Title: "A better move" recommended by chess.com but almost never played?
I played a game starting with

1. d4 d5 2. c4 dxc4 3. Nc3 a6 4. a4 Nc6 5. Nf3

Black's next move is 5... Bg4 and it was considered by chess.com as

> Inaccuracy (-0.28) A better move was 5... e5 (5... e5 6. d5 a5 7. e4 f6 8. e2 b4 9. g5 O-O 10. O-O)

But according to 365chess.com, the move 5... e5 is seldom played while 5... Bg4 is more popular with a high winning percentage for black. Why does chess.com consider 5... Bg4 as an inaccuracy?

# Answer
> 6 votes
Chess.com listed this as an inaccuracy because the engine is running at a limited depth, only looking at each move for a few seconds.

When I put the position after 5...Bg4 into Stockfish, it gave an evaluation of +0.12 at 16 ply. But at 18 ply, the evaluation dropped to -0.38. Most likely if you had run the analysis at "maximum" (which I realize is locked for non-premium members) the engine would have analyzed enough to know that 5...Bg4 was not an inaccuracy.

# Answer
> 0 votes
5...Bg4 isn't an inaccuracy, the chess.com engine just considers 5...e5 to be better. Deep Fritz, running at depth 23 on my computer, considers 5...Bg4 to be a slightly better move (giving a -0.31 evaluation). On 5...e5, it says that the endgame after 6.Nxe5 Nxe5 7.dxe5 Qxd1 8.Nxd1 is just equal.

Maybe chess.com's engine is better than my Deep Fritz, but that's not really the point. Engines consider one move in the opening to be a bit better than another all the time. It's important to take such differences with a grain of salt: if both moves are playable, choose the one that's easier/*more practical* to play.

In your scenario, 5...Bg4 clearly looks more comfortable than 5...e5. You're developing a piece and putting pressure on White's knight (which defends the d4-pawn). Meanwhile with ...e5, you're inviting White to push your knight offside.

---
Tags: opening, queens-gambit, websites, queens-gambit-accepted
---


# Question
Title: Does the chick promotion rule in dobutsu shogi really matter?
In dobutsu shogi, the chick (Japanese pawn) promotes to a chicken (Gold general). In my experience this promotion occurs only rarely and I suspect after much blundering.

Does the chick promotion rule in dobutsu shogi really matter? That is, does the game really change if chick promotion is dropped (and chicks become stuck on the last row instead)?

By really change, I mean the classification of a position (winning, losing or drawing) changing, or the precise sequence of moves to force a win from a winning position changing materially.

# Answer
> 9 votes
The promotion rule actually matters a lot. **With perfect play the game ends in a draw instead of a win for white/gote if you drop the promotion rule.** In fact, the evaluation of all four moves in the initial position changes in this way.

I have used two independent methods to get this result in order to double-check that there is no bug in my implementations:

1. Using an engine with alpha-beta search, namely my Stockfish fork for fairy chess variants (including shogi variants), I ran deep searches (~1h) before and after disabling the promotion rule, see the results below.
2. Since dobutsu shogi is a solved game, there are tablebase generators for it. I have used an open-source tablebase generator and modified it to disable promotions (I am not very familiar with this code base, but since the results of the two methods are consistent, my change seems to work fine). I ran the tablebase generation with both rule sets and checked the results, which you can find below.

---

## 1. Search results

input:

```
setoption name multipv value 4
setoption name hash value 4096
setoption name UCI_Variant value dobutsu
position startpos
go depth 90

```

output with promotion rule:

```
info depth 90 seldepth 87 multipv 1 score mate -43 nodes 2423491649 nps 889420 hashfull 338 tbhits 0 time 2724798 pv c1c2 a4a3 c2c1 b3b2 a1b2 c4b3 C@a1 C@a2 c1c2 a2a1+ b2a1 b3c2 b1c2 a3b3 c2b1 b4a3 E@b2 a3b4 b2c1 b3a3 a1b2 a3a4 b1c2 b4c4 b2c3 a4a3 c3b2 a3a2 C@a1 a2b2 c2b2 G@b3 b2b1 E@a3 G@c2 C@c3 c2b2 c4b4 b2a2 b4a4 a2a3 a4a3 a1a2 a3b4 b1a1 G@c2 a1b1 b4c4 E@a1 b3b4 a1b2 c4b3 a2a3 b4c4 b1a1 c2c1 b2c1 b3a3 G@a2 a3b3 a2b2 b3a4 b2a2 C@a3 c1b2 a3a2 a1a2 c3c2 C@b3 E@c3 b2c3 c4c3 b3b4+ a4b4 E@b2 c3b3 a2b1 b3b2 b1b2 E@a3 b2a1 E@b2 a1b1 G@a1 b1c2 C@c3
info depth 90 seldepth 87 multipv 2 score mate -43 nodes 2423491649 nps 889420 hashfull 338 tbhits 0 time 2724798 pv b1c2 b3b2 a1b2 c4b3 c2b1 a4a3 C@a1 C@a2 c1c2 a2a1+ b2a1 b3c2 b1c2 a3b3 c2b1 b4a3 E@b2 a3b4 b2c1 b3a3 a1b2 a3a4 b1c2 b4c4 b2c3 a4a3 c3b2 a3a2 C@a1 a2b2 c2b2 G@b3 b2b1 E@a3 G@c2 C@c3 c2b2 c4b4 b2a2 b4a4 a2a3 a4a3 a1a2 a3b4 b1a1 G@c2 a1b1 b4c4 E@a1 b3b4 a1b2 c4b3 a2a3 b4c4 b1a1 c2c1 b2c1 b3a3 G@a2 a3b3 a2b2 b3a4 b2a2 C@a3 c1b2 a3a2 a1a2 c3c2 C@b3 E@c3 b2c3 c4c3 b3b4+ a4b4 E@b2 c3b3 a2b1 b3b2 b1b2 E@a3 b2a1 E@b2 a1b1 G@a1 b1c2 C@c3
info depth 90 seldepth 87 multipv 3 score mate -43 nodes 2423491649 nps 889420 hashfull 338 tbhits 0 time 2724798 pv b1a2 a4a3 a2b1 b3b2 a1b2 c4b3 C@a1 C@a2 c1c2 a2a1+ b2a1 b3c2 b1c2 a3b3 c2b1 b4a3 E@b2 a3b4 b2c1 b3a3 a1b2 a3a4 b1c2 b4c4 b2c3 a4a3 c3b2 a3a2 C@a1 a2b2 c2b2 G@b3 b2b1 E@a3 G@c2 C@c3 c2b2 c4b4 b2a2 b4a4 a2a3 a4a3 a1a2 a3b4 b1a1 G@c2 a1b1 b4c4 E@a1 b3b4 a1b2 c4b3 a2a3 b4c4 b1a1 c2c1 b2c1 b3a3 G@a2 a3b3 a2b2 b3a4 b2a2 C@a3 c1b2 a3a2 a1a2 c3c2 C@b3 E@c3 b2c3 c4c3 b3b4+ a4b4 E@b2 c3b3 a2b1 b3b2 b1b2 E@a3 b2a1 E@b2 a1b1 G@a1 b1c2 C@c3
info depth 90 seldepth 85 multipv 4 score mate -42 nodes 2423491649 nps 889420 hashfull 338 tbhits 0 time 2724798 pv b2b3 c4b3 a1b2 a4a3 C@a1 C@a2 c1c2 a2a1+ b2a1 b3c2 b1c2 a3b3 c2b1 b4a3 E@b2 a3b4 b2c1 b3a3 a1b2 a3a4 b1c2 b4c4 b2c3 a4a3 c3b2 a3a2 C@a1 a2b2 c2b2 G@b3 b2b1 E@a3 G@c2 C@c3 c2b2 c4b4 b2a2 b4a4 a2a3 a4a3 a1a2 a3b4 b1a1 G@c2 a1b1 b4c4 E@a1 b3b4 a1b2 c4b3 a2a3 b4c4 b1a1 c2c1 b2c1 b3a3 G@a2 a3b3 a2b2 b3a4 b2a2 C@a3 c1b2 a3a2 a1a2 c3c2 C@b3 E@c3 b2c3 c4c3 b3b4+ a4b4 E@b2 c3b3 a2b1 b3b2 b1b2 E@a3 b2a1 E@b2 a1b1 G@a1 b1c2 C@c3

```

output without promotion rule:

```
info depth 90 seldepth 52 multipv 1 score cp 0 nodes 2745548262 nps 965315 hashfull 244 tbhits 0 time 2844199 pv b1a2 a4a3 a2b1 b3b2 a1b2 c4b3 C@a1 b4a4 c1c2 b3c2 b1c2 G@b3 b2c3 C@c4 c3b2 a4b4 E@a2 c4c3 c2c1 b3b2 c1b2 E@b3 b2b1 b3a4 G@b2 b4c4 b1c1 a4b3 a2b3 a3b3 b2b3 c4b3 G@b2 b3c4 E@b3 c4b4 c1b1 G@a3 b3a2 b4c4 b1c1 E@a4 c1b1 a4b3 b2b3 a3b3 a2b3 c4b3 G@b2 b3b4 E@b3
info depth 90 seldepth 52 multipv 2 score cp 0 nodes 2745548262 nps 965315 hashfull 244 tbhits 0 time 2844199 pv b1c2 b3b2 a1b2 c4b3 c2b1 a4a3 C@a1 b4a4 c1c2 b3c2 b1c2 G@b3 b2c3 C@c4 c3b2 a4b4 E@a2 c4c3 c2c1 b3b2 c1b2 E@b3 b2b1 b3a4 G@b2 b4c4 b1c1 a4b3 a2b3 a3b3 b2b3 c4b3 G@b2 b3c4 E@b3 c4b4 c1b1 G@a3 b3a2 b4c4 b1c1 E@a4 c1b1 a4b3 b2b3 a3b3 a2b3 c4b3 G@b2 b3b4 E@b3
info depth 90 seldepth 50 multipv 3 score cp 0 nodes 2745548262 nps 965315 hashfull 244 tbhits 0 time 2844199 pv b2b3 c4b3 a1b2 a4a3 C@a1 b4a4 c1c2 b3c2 b1c2 G@b3 b2c3 C@c4 c3b2 a4b4 E@a2 c4c3 c2c1 b3b2 c1b2 E@b3 b2b1 b3a4 G@b2 b4c4 b1c1 a4b3 a2b3 a3b3 b2b3 c4b3 G@b2 b3c4 E@b3 c4b4 c1b1 G@a3 b3a2 b4c4 b1c1 E@a4 c1b1 a4b3 b2b3 a3b3 a2b3 c4b3 G@b2 b3b4 E@b3
info depth 90 seldepth 59 multipv 4 score cp 0 nodes 2745548262 nps 965315 hashfull 244 tbhits 0 time 2844199 pv c1c2 a4a3 c2c1 b3b2 a1b2 c4b3 C@a1 b4a4 c1c2 b3c2 b1c2 G@b3 b2c3 C@c4 c3b2 a4b4 E@a2 c4c3 c2c1 b3b2 c1b2 E@b3 b2b1 b3a4 G@b2 b4c4 b1c1 a4b3 a2b3 a3b3 b2b3 c4b3 G@b2 b3c4 E@b3 c4b4 c1b1 G@a3 b3a2 b4c4 b1c1 E@a4 c1b1 a4b3 b2b3 a3b3 a2b3 c4b3 G@b2 b3a4 E@b3 a4b4 b1c1 G@a3 b3a2 b4c4 c1b1 E@b3

```

See the UCI protocol description for details on the meaning of the in- and output.

## 2. Tablebase results

input:

```
show lines

```

output with promotion rule:

```
Gc4-c3 : #-78  (25.00%)
Lb4-c3 : #-78  (25.00%)
Lb4-a3 : #-78  (25.00%)
Cb3xb2 : #-76  (24.99%)

```

output without promotion rule:

```
Cb3xb2 : 0     (25.00%)
Gc4-c3 : 0     (25.00%)
Lb4-c3 : 0     (25.00%)
Lb4-a3 : 0     (25.00%)

```

---

Please note:

* The mate distances differ for two reasons:
    + Stockfish counts the mate distance in full moves (unless you enable the USI protocol), whereas the tablebase generator counts in ply (half moves).
    + The search does not not necessarily find the shortest way to mate, whereas the tablebase result should be accurate.
* The two softwares also use different coordinate systems to describe the squares (the ordering of ranks is inverted), so be careful not to mix them up when comparing move strings.

# Answer
> 2 votes
I am now convinced that Fabian Fichter's answer is correct. The following commentary on Fabian's answer may help to convince others of the same.

## 1. Position that seems to be impacted by removing chick promotion

Analysing the posted results from the modified Stockfish, all games converge pretty quickly on the following position: S/-l-/ge-/-E-/-LG/cC.

```
$ ./dobutsu -vs900
Loading tablebase... done
1. setup S/-l-/ge-/-E-/-LG/cC
1. show board
  ABC
 +---+
1| l | c
2|ge |
3| E |
4| LG| *C
 +---+
1. show lines
Eb3xa2 : #-72  (67.13%)
C  *a4 : #-70  (32.87%)   <---  apparently quite strong
Gc4-c3 : #-46  ( 0.00%)
C  *c2 : #-36  ( 0.00%)
C  *c1 : #-28  ( 0.00%)
Eb3-a4 : #-26  ( 0.00%)
Lb4-a4 : #-26  ( 0.00%)
C  *a1 : #-24  ( 0.00%)
C  *c3 : #-22  ( 0.00%)
C  *a3 : #-20  ( 0.00%)
Eb3-c2 : #-12  ( 0.00%)
Lb4-c3 : #-2   ( 0.00%)
Lb4-a3 : #-2   ( 0.00%)

```

Sente then plays `C*a4`, dropping their chick in the bottom left corner. I initially thought this a pretty wasteful drop but according to the table base it is actually not at all bad.

```
1. C  *a4
  ABC
 +---+
1| l | *c
2|ge |
3| E |
4|CLG|
 +---+

```

Now something interesting happens. The table base agrees with Stockfish that stepping the Lion to the side is a draw, but what about dropping a chick to fight a chick?

```
2. show lines
C  *a3 : #69   (99.57%)   <---  winning chick drop
C  *c2 : #91   ( 0.21%)
C  *c1 : #91   ( 0.21%)
C  *a1 : 0     ( 0.00%)
Ga2-a1 : 0     ( 0.00%)
Eb2-c1 : 0     ( 0.00%)
Eb2-a1 : 0     ( 0.00%)
Lb1-a1 : 0     ( 0.00%)   <---  draws the game
C  *c3 : #-28  ( 0.00%)
Lb1-c1 : #-22  ( 0.00%)
Eb2-c3 : #-20  ( 0.00%)
Eb2-a3 : #-20  ( 0.00%)
Ga2-a3 : #-18  ( 0.00%)
Lb1-c2 : #-2   ( 0.00%)
2. C  *a3
  ABC
 +---+
1| l |
2|ge |
3|cE |
4|CLG| *
 +---+

```

Now the chick on `a3` is one step away from promoting and moreover would give check on promoting, which would force the Sente lion to take it. The only problem is that the best move involves losing the chick on `a3` and also that we are still pretty far from a checkmate. Therefore we are going to take a bit of a short-cut, such that we lose faster, but without losing for other reasons such as giving away material needlessly.

```
3. show lines
Ca4xa3 : #-68  (92.84%)   <---  catches chick about to promote
Gc4-c3 : #-62  ( 7.16%)
Eb3xa2 : #-32  ( 0.00%)   <---  shortcut
Eb3-c2 : #-8   ( 0.00%)   <---  give away elephant
Lb4-c3 : #-2   ( 0.00%)   <---  stupid
Lb4xa3 : #-2   ( 0.00%)   <---  stupid
3. Eb3xa2
  ABC
 +---+
1| l | *
2|Ee |
3|c  |
4|CLG| G
 +---+
4. show lines
Lb1xa2 : #31   (100.00%)
Lb1-c2 : #-10  ( 0.00%)
Lb1-c1 : #-6   ( 0.00%)
Lb1-a1 : #-6   ( 0.00%)
Ca3xa4+: #-2   ( 0.00%)
Eb2-c3 : #-2   ( 0.00%)
Eb2-c1 : #-2   ( 0.00%)
Eb2-a1 : #-2   ( 0.00%)
4. Lb1xa2
  ABC
 +---+
1|   | e
2|le |
3|c  |
4|CLG| *G
 +---+

```

We seem to have succeeded in preserving the threat of the sacrificial promoting chick, so let's continue!

```
5. show lines
G  *b3 : #-30  (100.00%)
G  *a1 : #-24  ( 0.00%)
G  *c3 : #-20  ( 0.00%)
Gc4-c3 : #-18  ( 0.00%)
G  *c2 : #-14  ( 0.00%)
G  *c1 : #-10  ( 0.00%)
G  *b1 : #-10  ( 0.00%)
Ca4xa3 : #-8   ( 0.00%)
Lb4-c3 : #-2   ( 0.00%)
Lb4-b3 : #-2   ( 0.00%)
Lb4xa3 : #-2   ( 0.00%)
5. G  *b3
  ABC
 +---+
1|   | *e
2|le |
3|cG |
4|CLG|
 +---+
6. show lines
Ca3xa4+: #29   (100.00%)   <---  sacrificial promoting chick check
E  *c3 : #-30  ( 0.00%)
E  *c1 : #-28  ( 0.00%)
Eb2-c1 : #-28  ( 0.00%)
Eb2-a1 : #-28  ( 0.00%)
La2-b1 : #-28  ( 0.00%)
La2-a1 : #-28  ( 0.00%)
E  *c2 : #-26  ( 0.00%)
E  *a1 : #-24  ( 0.00%)
E  *b1 : #-12  ( 0.00%)
Eb2-c3 : #-12  ( 0.00%)
La2xb3 : #-2   ( 0.00%)

```

And there it is, the sacrificial promoting chick as the best move! Let's see what happens.

```
6. Ca3xa4+:
  ABC
 +---+
1|   | ce
2|le |
3| G |
4|rLG| *
 +---+
7. show lines
Lb4xa4 : #-28  (100.00%)   <---  take chick (forced if promoted)
Gc4-c3 : #-2   ( 0.00%)
Gb3-c3 : #-2   ( 0.00%)
Gb3-a3 : #-2   ( 0.00%)
Gb3xb2 : #-2   ( 0.00%)
Lb4-c3 : #-2   ( 0.00%)
Lb4-a3 : #-2   ( 0.00%)

```

Now let's see what happens if we change that rooster to a chick:

```
7. setup S/---/le-/-G-/cLG/ec
1. show board
  ABC
 +---+
1|   | ce
2|le |
3| G |
4|cLG| *
 +---+
1. show lines
Gc4-c3 : #-90  (100.00%)
Gb3xb2 : #-30  ( 0.00%)
Lb4xa4 : #-28  ( 0.00%)
Gb3-c3 : #-10  ( 0.00%)
Gb3-a3 : #-8   ( 0.00%)
Lb4-c3 : #-2   ( 0.00%)
Lb4-a3 : #-2   ( 0.00%)

```

In this position the best move puts checkmate 88 (90-2) moves away, which is further away from checkmate than the starting position, making it plausible that when analysed it will lead to another position that without promoting chick power is suddenly much further from mate than before (ad infinitum). If true **that would make position G/---/le-/cG-/CLG/e (see below) a draw instead of a win without chick promotion**.

```
  ABC
 +---+
1|   | *e
2|le |
3|cG |
4|CLG|
 +---+

```

## 2. Correctness of exhaustive search

Assuming that the used table base generator is a correct exhaustive search, it seems that Fabian's patch should succeed in disabling chick promotions as file `moves.c` is the only place that `POS_FLAGS` is used (except for a use in `validation.c` to check position structs) and indeed seems purpose-built to disable promotions.

```
/* clear promotion bits for pieces that can't be promoted */
status &= POS_FLAGS;

```

---
Tags: rules, chess-variants, shogi
---


title: Knight moves which way?

text:
# Question
Title: Knight moves which way?
Does the knight move two steps forward and then to left or right or does it move one step forward and then diagonally to left or right? I was taught move one square then to right or left My partner says other way and we are fighting over it! Please can someone help.

# Answer
> 2 votes
**Both of you are correct**; you are just thinking of it in different ways. The following picture shows a knight and the squares where it could be after one move.

Here's another picture that shows both methods:

# Answer
> 0 votes
Like everyone says, the two definitions are equivalent, but if you want an official-looking source, here is the quote from the USCF rulebook:

> **8E. The knight.** The knight’s move is composed of two different steps. First, it makes one step of one single square along the rank or file on which it stands. It does not land on that square, as its move is not complete (9A). Then, still moving away from the square of departure, it moves one step of one single square on a diagonal. It does not matter if the square of the first step is occupied.
>
> This move is sometimes called an L move, as it is equivalent to moving the knight two squares vertically, then one square horizontally (or two squares horizontally, then one square vertically). Note that the knight always moves to a square different in color than that of its starting square. A knight has a maximum of eight possible moves.

U.S. Chess Federation. United States Chess Federation's Official Rules of Chess, Sixth Edition (Kindle Locations 941-946). Kindle Edition.

There are yet more ways of looking at the knight's move. This one is from the FIDE handbook, and while clearly correct I don't think it reflects the way most people think of the move:

> **3.6** The knight may move to one of the squares nearest to that on which it stands but not on the same rank, file or diagonal.

https://www.fide.com/fide/handbook.html?id=208&view=article

---
Tags: learning
---


# Question
Title: What is the value of most starting positions in dobutsu shogi?
In dobutsu shogi, the usual starting position is a *trébuchet* or *full-point mutual zugzwang* position, but other likely (starting) positions can have a completely different value.

If we arrange the pieces in a different way but still mostly on the back rank and mostly on the board, are most of those positions also trébuchets or do they share another commonality?

# Answer
The first surprise is that **if we change the starting position to have mirror symmetry (like western chess) instead of rotational symmetry (like Japanese chess) we get a drawn position** in which any lion move is losing.

```
1. setup S/elg/-c-/-C-/ELG/
1. show board
  ABC
 +---+
1|elg|
2| c |
3| C |
4|ELG| *
 +---+
1. show lines
Cb3xb2 : 0     (50.00%)
Gc4-c3 : 0     (50.00%)
Lb4-c3 : #-46  ( 0.00%)
Lb4-a3 : #-46  ( 0.00%)

```

Giraffes and elephants are freely exchanged in winning lines, so they must be very close in value. Still, elephants (like bishops in western chess) suffer from being restricted to half of the squares, which probably explains that **giraffes versus elephants is a win for the giraffes**.

```
1. setup S/ele/-c-/-C-/GLG/
1. show board
  ABC
 +---+
1|ele|
2| c |
3| C |
4|GLG| *
 +---+
1. show lines
Lb4-c3 : #25   (50.00%)
Lb4-a3 : #25   (50.00%)
Cb3xb2 : #53   ( 0.00%)
Gc4-c3 : #53   ( 0.00%)
Ga4-a3 : #53   ( 0.00%)
1. setup S/glg/-c-/-C-/ELE/
1. show board
  ABC
 +---+
1|glg|
2| c |
3| C |
4|ELE| *
 +---+
1. show lines
Lb4-c3 : #-32  (50.00%)
Lb4-a3 : #-32  (50.00%)
Cb3xb2 : #-24  ( 0.00%)

```

Or is it?

```
1. setup S/lee/-c-/-C-/GGL/
1. show board
  ABC
 +---+
1|lee|
2| c |
3| C |
4|GGL| *
 +---+
1. show lines
Ga4-a3 : 0     (50.00%)
Lc4-c3 : 0     (50.00%)
Cb3xb2 : #-62  ( 0.00%)
1. setup S/eel/-c-/-C-/GGL/
1. show board
  ABC
 +---+
1|eel|
2| c |
3| C |
4|GGL| *
 +---+
1. show lines
Ga4-a3 : 0     (50.00%)
Lc4-c3 : 0     (50.00%)
Cb3xb2 : #-58  ( 0.00%)

```

**Starting giraffes draw**, but beware of chick fights...

```
1. setup S/lgg/-c-/-C-/EEL/
1. show board
  ABC
 +---+
1|lgg|
2| c |
3| C |
4|EEL| *
 +---+
1. show lines
Cb3xb2 : 0     (33.33%)
Eb4-c3 : 0     (33.33%)
Eb4-a3 : 0     (33.33%)
Lc4-c3 : #-48  ( 0.00%)
1. setup S/ggl/-c-/-C-/EEL/
1. show board
  ABC
 +---+
1|ggl|
2| c |
3| C |
4|EEL| *
 +---+
1. show lines
Cb3xb2 : 0     (33.33%)
Eb4-c3 : 0     (33.33%)
Eb4-a3 : 0     (33.33%)
Lc4-c3 : #-50  ( 0.00%)

```

...and **starting elephants also draw**, but beware of lion moves.

What about side lions in the standard position?

```
1. setup S/lge/-c-/-C-/EGL/
1. show board
  ABC
 +---+
1|lge|
2| c |
3| C |
4|EGL| *
 +---+
1. show lines
Cb3xb2 : 0     (50.00%)
Lc4-c3 : 0     (50.00%)
1. setup S/egl/-c-/-C-/EGL/
1. show board
  ABC
 +---+
1|egl|
2| c |
3| C |
4|EGL| *
 +---+
1. show lines
Cb3xb2 : 0     (50.00%)
Lc4-c3 : 0     (50.00%)

```

**Central giraffe with lion to the side is a draw**.

```
1. setup S/leg/-c-/-C-/GEL/
1. show board
  ABC
 +---+
1|leg|
2| c |
3| C |
4|GEL| *
 +---+
1. show lines
Eb4-a3 : #65   (100.00%)
Cb3xb2 : 0     ( 0.00%)
Ga4-a3 : 0     ( 0.00%)
Eb4-c3 : 0     ( 0.00%)
Lc4-c3 : #-44  ( 0.00%)
1. setup S/gel/-c-/-C-/GEL/
1. show board
  ABC
 +---+
1|gel|
2| c |
3| C |
4|GEL| *
 +---+
1. show lines
Cb3xb2 : #51   (99.94%)
Eb4-c3 : #65   ( 0.06%)
Ga4-a3 : 0     ( 0.00%)
Eb4-a3 : #-64  ( 0.00%)
Lc4-c3 : #-52  ( 0.00%)

```

It is a **win if the elephant is in the middle**. Notice that moving the elephant towards the enemy lion is winning in both positions and moving the lion forward is losing, but in the mirror-symmetric case, chick fight is also winning and elephant towards the other side is losing. At least in this case shogi is more drawish than western chess!

In summary, it seems that trébuchets are quite rare (we did not find any), and most starting positions are draws with the occasional win for the starting player or loss for positions with an obvious weakness.
> 3 votes

---
Tags: chess-variants, shogi
---


# Question
Title: Expected score in my first FIDE tournament
Going to play my first international tournament next week.

As this is my first I do not have a FIDE ELO (I have national rating however).

How will my games be rated and how is my expected score for each game calculated?

# Answer
> 4 votes
The FIDE Rating Regulations give details of how the system works. You should scroll down to section **8. The working of the FIDE Rating System** which describes the mathematical tables and formulae used for calculating ratings.

Note that a fudge factor called the "Development Coefficient" is used in calculating ratings which determines by how much new results affect your existing rating once you have one.

> K = 40 for a player new to the rating list until he has completed events with at least 30 games
>
> K = 20 as long as a player's rating remains under 2400.
>
> K = 10 once a player's published rating has reached 2400 and remains at that level subsequently, even if the rating drops below 2400.
>
> K = 40 for all players until their 18th birthday, as long as their rating remains under 2300.

As a new player you will have a high K which will mean that your rating will change rapidly if you have results which vary widely from your previous results.

# Answer
> 2 votes
If you're unrated, you don't really have an expected score. How can anything be expected when your rating is totally unknown? But the win expectancy table is sometimes used in *reverse*, to calculate the rating of an unrated player based on the *actual* score.

There are actually a few different formulas that might be used to determine your initial rating, depending on the type of tournament and your score, according to the FIDE Ratings Regulations:

> 8.2 Determining the Rating 'Ru' in a given event of a previously unrated player.
>
> 8.21 If an unrated player scores zero in his first event his score is disregarded.
> First determine the average rating of his competition 'Rc'.
>
> (a) In a Swiss or Team tournament: this is simply the average rating of his opponents.
>
> (b) The results of both rated and unrated players in a round-robin tournament are taken into account. For unrated players, the average rating of the competition 'Rc' is also the tournament average 'Ra' determined as follows:
> (i) Determine the average rating of the rated players 'Rar'.
> (ii) Determine p for each of the rated players against all their opponents.
> Then determine dp for each of these players.
> Then determine the average of these dp = 'dpa'.
> (iii) 'n' is the number of opponents.
> Ra = Rar - dpa x n/(n+1)
>
> 8.22 If he scores 50%, then Ru = Ra
>
> 8.23 If he scores more than 50%, then Ru = Ra + 20 for each half point scored over 50%
>
> 8.24 If he scores less than 50% in a Swiss or team tournament: Ru = Ra + dp
>
> 8.25 If he scores less than 50% in a round-robin: Ru = Ra + dp x n/(n+1)

Let's say you play in a Swiss and lose to a 2000, beat an 1800, draw to a 1900, draw a 1750, and lose to a 1950.

The first step is to calculate the average rating of your opponents. In this example, it is 1880. Since you scored less than 50%, we then calculate dp using table 8.1a (which is at the link.) You scored 2/5, which is 40% or 0.4. According to the table, this gives a dp of -72. So your rating for this tournament would be 1880 - 72 = 1808.

When your opponents are calculating their own ratings, this applies:

> 8.52 If the opponent is unrated, then the rating is determined at the end of the event. This applies only to round-robin tournaments. In other tournaments games against unrated opponents are not rated.

So your games against them would not count towards their ratings, in this case. But if this was a round-robin instead, then your rating would be calculated first (using the slightly more complicated process for round-robins described above), and their win expectancy against you would then be determined based on your new rating.

---
Tags: rating, tournament, elo, fide
---


title: Why are Leela's fans so passionate?

text:
# Question
Title: Why are Leela's fans so passionate?
The neural-network engine Leela is a relatively new one. It's also got some extremely passionate fans. For example they write things like this:

> Wait 5-6 months, and we will see SF8 on uber-duper logarithmic in cores Elo-wise 32 cores being smashed by Lc0 on my puny single 1060.

Watching Leela's fans argue up and down Talkchess, Chess.com's computer championship chat and TCEC chat, about how their engine is / isn't superior to Stockfish because of \[multitude of factors\] or how their engine is going to crush Stockfish after the next learning rate drop, about how the "end of an era" is at hand, etc, makes me wonder: why are Leela's fans so passionate?

I don't recall seeing anything similar to this before Leela showed up. It's not like Leela is so special either: before Leela showed up, Stockfish, Komodo and Houdini dominated engine chess, and there were periods when any of the three were the strongest engine. But I don't recall seeing any of their fans displaying the same level of intensity.

# Answer
> 16 votes
You can't really objectively answer this question, but I'll share my view.

One of the important factors to take into account is that Leela Chess Zero project requires tremendous computational resources to complete. The way project attains those resources is by convincing large number of people to donate part of their machine time to that project.

To make this work, project needs to sustain strong community that clearly sees its goals, ideas and progress. There have been done many things for that: there is a very active discord chat, google groups, blog, you can see lots of graphs and metrics regarding project status, there are very detailed spreadsheets, etc. Also some chess youtubers helped this project grow community (e.g. KingsCrusher and ChessNetwork) by featuring it in their videos.

Beating StockFish is one of the very important goals of this community.

When people are united around some idea, it's because they are passionate about it. The behavior you are describing looks the same as when people argue about politics, football, religion, nationality, etc.

# Answer
> 9 votes
Leela is special because it's the first strong open-source deep-learning engine. Defeating Stockfish (and also Komodo and Houdini) convincingly on all settings is a very significant milestone, practically more important than Google's AlphaZero. Google's system is inaccessible to anyone but themself.

Human-understandable evaluation function has always been part of engine design, since it started around 30 years ago. Leela, running on a complex neural network evaluation will be the first open-source "intelligent" leading chess engine. The engine "learns" chess by NN machine learning, a much smarter programming technique than random heuristics programming. Engine programmers no longer have to guess/hardcode engine heuristics!

For the first time in history, we will have access to a free and strong "intelligent" chess engine. Stockfish is also strong but it knows nothing about chess.

The era of none-AI evaluation will soon end. Stockfish, Houdini and Komodo will soon fade in existence. Chess engines adopting classical programming techniques will no longer lead the world. Leela is the future, Stockfish will be history.

# Answer
> 4 votes
Anytime a group of people get extremely hyped about something (and especially when they aggressively bash alternatives), there's a good chance this is just human tribalism at work. Leela may become extremely strong in the near future, but to say with 100% certainty this will happen now is naive.

People also like change. Stockfish is a revolutionary engine (strong evaluation function based on a huge number of heuristics, and an incredibly fast searching function), but it's been the top dog for a long time. No matter how good things are, eventually people want something even better. It's what drives society forward.

Again, I'm not saying it's impossible for Leela to live up to its hype. It's just that this hype you're describing isn't currently warranted.

---
Tags: engines, stockfish, leela
---


title: Alpha Zero vs Lc0 - time for self-play

text:
# Question
Title: Alpha Zero vs Lc0 - time for self-play
Alpha Zero defeated Stockfish after only 9 hours of self-play. On the other hand, Lc0, has been training for several months and while attaining impressive strength (to say the least...) it's still not crushing Stockfish. What can be the reason for such a dramatic difference in learning efficiency?

# Answer
In short, because **DeepMind has TPUs**. Lots and lots of TPUs.

By far, the most time-consuming part of the training process is **generating self-play games**. DeepMind used 5000 TPUs to generate self-play games, which is a lot of processing power. Meanwhile, Lc0 crowdsources processing power from volunteer clients, which is much slower.

From the DeepMind paper published December 2017 (emphasis mine):

> We trained a separate instance of AlphaZero for each game. Training proceeded for 700,000 steps (mini-batches of size 4,096) starting from randomly initialised parameters, using **5,000 first-generation TPUs** to generate self-play games and **64 second-generation TPUs** to train the neural networks.

To achieve the level of performance that AlphaZero got against the (sub-optimally tuned) Stockfish version 8, the training run took about 9 hours and 44 million self-play games for chess:

Meanwhile, the Lc0 project got started sometime in January 2018, and by April 2018, they'd only generated **8.2 million out of the needed 44 million games**. I believe they were generating about 200k games per day at the time.

They also came across a lot of bugs in the process and were figuring out a lot of things as they went, so when the first training run plateaued, the best net was not as good as AlphaZero. Since then, the Lc0 project has actually restarted the training run multiple times:

* **old main:** The original 192x15 "main" run, using the original `lczero.exe` engine. It ended in August 2018, with the last net being ID595. (These nets don't seem to be listed anymore though? The early IDs at the bottom of the net list seem to be these test nets.)
* **test10**: The original 256x20 test run. This was a separate pipeline using a completely rewritten `lc0.exe` engine that was much faster at generating self-play games. Net numbering for this run started with ID10000 on June 27, 2018, and ended with ID11262 on August 30, 2018.
* **test20**: A run with various changes, starting with ID20001 on August 30, 2018 and ending with ID22201 on November 16, 2018.
* **test30**: A run testing various new ideas, starting with ID30001 on September 9, 2018. As of January 14, 2019, the best net was ID32598.
* **test40**: The December 6, 2018 AlphaZero paper revealed a lot of differences between what DeepMind did and what Lc0 did, and it looks like a new test run started with ID40001 on January 8, 2019. As of January 14, 2019, the best net was ID40202.

To get a sense of how well Lc0 is doing compared to AlphaZero, it's more useful to look at the Elo with respect to total number of games generated, not time elapsed. Here's what the graph looks like for the entire Lc0 project as of January 14, 2019 (note that this is self-play Elo, which is inflated compared to actual Elo):

As you can see, they've reset the training run many times. There were also a number of bootstrap mini-resets during the original main run to fix some critical bugs, and there was also a temporary test35 to test the newly revealed configuration settings from the December 2018 AlphaGo paper. Yep, this isn't confusing at all! (/s)

There are lots of calculations and graphs in this spreadsheet here that compares lc0's performance with AlphaZero. For example, here's the graph from the first old main run (under the "Graphs" tab):

From that link, an explanation of what "Leela Max" is:

> "Leela Max" is Leela's theoretical maximum performance when given hardware and/or time to the point of absolute diminished returns. It may be more comparable to AlphaZero, as AlphaZero operated on 4.8 million nodes per move, whereas a conventional setup only gets a small fraction of that.

---

These days, the self-play generation speed is much faster than it was at the beginning. As of January 14, 2019, it looks like the project is generating about 1.5 million games per day. But at this speed, it'll still take a month to achieve what DeepMind achieved in 9 hours. More like double the time, really, if the training games are being diverted towards two separate runs.
> 11 votes

# Answer
This is happening because AlphaZero and Leela aren't playing against the same Stockfish. If you read the paper, AlphaZero beat Stockfish 8 (it also played a series against Stockfish 9 - same logic applies however). Both these versions of Stockfish are old, and significantly inferior to the latest version of Stockfish.

AlphaZero beat Stockfish 8 by +155 -6 =839. That's a ~50 elo difference. On the other hand Stockfish 10 is better than Stockfish 8 by ~100 elo. Leela, playing against Stockfish Dev (which is even better than Stockfish 10 - the engine is continuously updated) and not Stockfish 8, could be as good as AlphaZero yet fail to crush Stockfish. It would crush Stockfish 8 alright, but not Stockfish Dev.

On a side note: it's not clear that AlphaZero would crush Stockfish 10 either, or vice versa, because elo isn't transitive: if A beats B by 50 elo and B beats C by 50 elo, it doesn't mean that A beats C by 100 elo.

**Edit:** To illustrate, in the TCEC cup semifinals, Leela vs. Stockfish, the version of Stockfish that played was Stockfish 270918. The last six numbers is the date - Stockfish as of the 27th of the 9th month of 2018. You can see from the link above that this version of Stockfish is roughly 100 elo stronger than Stockfish 8, so the fact that Leela performs worse against it is not a surprise.
> 6 votes

---
Tags: engines, alphazero, leela
---


# Question
Title: Why bother with human chess when AI is superior?
Before I get to my question couple things to get out of the way:

* This question is a sensitive subject. But I assure you that I'm not a troll, I have deep respect for your community. It is my first question here, so please be gentle.
* I am a beginner chess player with mere 50 games that I've played total in my whole life.
* By asking this question I'm trying to uncover answer to the question: "What do we do as humanity when AI proves to be superior in all ways 100 years from now? - not just chess". I'm asking here specifically because I'm assuming "you've been there, done that"

With that out of the way: What motivates you to keep playing chess? I notice that lot of players here are very focused on ranking, too, so it's not purely social there is some need to be better (or even perhaps to be "the best"). But what can you do when you've worked hard for your ranking but you know that a couple silicon chips have a ranking superior to yours? And that you will never catch up (the gap between chess abilities in AI and humans will just widen). Is it something that just never bothered you in the first place? How come? If it did bother you but it doesn't any longer, how did you get through that slump?

Or am I making the wrong assumption? Are you into chess in some ways AI is INFERIOR to the human mind and you are fascinated by the ways that human mind still remains superior to AI regardless of the historic AI-human match outcomes? Or perhaps you even want to prove this somehow?

Or are we talking about a situation much like horse racing? Yes, horse races still make billions of dollars around the world, even though SR71 could beat any horse with it's Mach 6 performance? Is it just a question of the pure feeling that's unique experience of playing and watching human chess? Same as a horse race can never be replicated with robot horses, neither can chess?

What aspects of chess as a game allow the human chess-playing community to persist despite the existence of chess computers?

# Answer
I think one of the reasons humanity continues to play gams that computers will always win at is that chess is a useful tool to inprove critical thinking skills, such as pattern recognition and analysis of consequences. No matter how good at chess computers become, and even if chess is one day solved, humans can learn the game and still enjoy it, not to be the best on the planet, but to improve oneself and also for entertainment. Lord knows no one plays chess for the fame or the lifestyle.

Additionally, chess doesn't have to be played with computers. Two humans can enjoy a game of chess regardless of their skill level because it's a form of competition. It's also one of the most widespread forms of mental competition, so for those who don't enjoy physical competitions like other sports, chess can be appealing.

We still teach our children to play games like Tic-Tac-Toe (or Noughts and Crosses, or whatever you wish to call it), even though it's solved. The idea, apart from providing relief to the kids' parents, would be that they learn. Chess, and other activities, are not about being the best in the world or defeating computers. They're about the journey to get there.

Another reason humans don't care that much about being inferior to computers and AI is that we can simply exclude those from competing. Sure, cheetahs might be faster than Usain Bolt, but humans don't care; we don't allow cheetahs to race us in competition.
> 3 votes

---
Tags: training, world-championship, chess-ai
---


# Question
Title: Story of unexpectedly high (400+) Elo rising in few months (reaching 2500 Elo mark)
I'm sorry for being vague, but that's exactly my problem: I can't find an online blog post of a German/Scandinavian master anymore which illustrated a case of a young boy from Eastern Europe who managed to reach 2500 mark (in a few months time span) thanks to some suspect tournaments and timing. His coach fine-tuned everything to exploit the delay in updating the Elo list, combined with an excellent performance on a local tournament.

Does anyone can recall a similar story?

I'd really love to read the post again. It was backed up with data from the FIDE official site.

# Answer
> 5 votes
Ok, I finally got it!!! Here is the link I've been looking for: Zibbit's blog

---
Tags: elo, cheating
---


# Question
Title: AlphaZero and the revenge of the Artificial Intelligence
Answering this question, @SmallChess offered this answer:

> Before Google's chess journey, the chess engine community believed: AI chess will not beat classical programming because neural networks (or other models) run much slower.

1. I was looking for a reference to this quote. Did someone make this prediction in the past?
2. I have another, perhaps more fundamental question related to another part of @SmallChess' answer:

> AI machine learning is not new to chess. There were serious attempts before Google established. Unfortunately, nobody had the determination, skills and resources to do a good job.

Is it possible to pin down precisely what they have done better than others? Could it be simply that they use a lot more of computing ressources than before?

3. Subsidiary question: For a layman, who doesn't know how to compare TPU
and CPU, instead of 4 hours, how long would Alphazero's training have taken with Stockfish's configuration? (44 threads on 44 cores - two 2.2GHz Intel Xeon Broadwell CPUs with 22 cores instead of a single machine with 4 first-generation TPUs. See Supplementary Materials for their Science paper.)

# Answer
1. Pretty much everybody. The reason being that it is STILL slower. The evaluation function for alphazero has WAY more variables so despite more computing power, alphazero can only calculate a fraction of number of positions than stockfish. However the evaluation function for alphazero is much much better due to self-learning and also takes forever to calculate.

https://arxiv.org/pdf/1712.01815.pdf

Consider this. Google used 5000 super computers to train the AI to play before the game. Now consider what happens if you give stockfish access to 5000 super computers to think for 4 hours and if it memorized all those lines.

2. The issue comes down to computing power.
3. Not in your lifetime.

It is a bit difficult to find Ghz to tflop conversions but consider this.

https://www.pugetsystems.com/labs/hpc/Intel-Core-i9-7900X-and-7980XE-Skylake-X-Linux-Linpack-Performance-1059/

28 cores on 2.6Ghz gives about 1.123Tflops. So for 88 cores running at 2.2Ghz each is around 3Tflops. So your system gives around 3Tflops.

Now I can't find any information on the first generation TPUS but the second generation TPUs have 180 Tflops each.

https://en.wikipedia.org/wiki/Tensor\_processing\_unit

So 1 TPU = 60 of your systems. So 5000\*60\*4 = 1200000 hours = 136 years.

Also should clearly show how unfair the alphazero vs stockfish match is.

Edit: I made a mistake, you said 2 22 core systems. My calculations had 88 cores. So you would need to double the previous total to 272 years.
> 2 votes

# Answer
**(1)** Let's go back to 2016 when Google had just beaten the best Go player...

http://talkchess.com/forum3/viewtopic.php?f=2&t=59072&hilit=machine+learning+chess+slow+machine+learning&start=50

Milos who I believe is a PhD claimed machine learning had been tried "N" times.

Dr Bob, the legendary engine programmer who wrote Crafty believed NN was too slow.

**(2)**

> Is it possible to pin down precisely what they have done better than others? Could it be simply that they use a lot more of computing ressources than before?

* Google indeed had more computing resources but that's not all ...
* Google had a superior deep learning model
* Google adopted MCTS instead of pure alpha-beta
* Google developed the model from self-playing, not like learning from GM games

This was the network used in NeuroChess. It's a shallow network in our modern standard. It's **NOT** a deep NN.

(3). I suspect it'd take weeks if not months. Not sure.
> 1 votes

---
Tags: stockfish, programming, alphazero
---


# Question
Title: Is it possible for a move to be recomended by engines but rejected by professional human players?
Am wondering if it is possible for a move to be considered "good" by engines but is rejected by professional human players. One possible reason that I can think of is that the in order for this move to be successful, one has to play exactly right for the next 20 moves or so, which is easy for engines but difficult for human players.

# Answer
> 12 votes
I see three situations, where something like you describe could happen:

1. wild tactical positions with open king, where moves have to be very precise and many humans might be too scared to enter such position
2. Many composed studies feature surprising moves that could be rejected by humans. For instance studies in which you give up all your material except for say a bishop with which you mate somehow. In most positions you can't win with a bishop only, so lines leading to such positions would not be considered usually.
3. some of the more tricky endgames feature very unnatural/inhuman moves that would be rejected by human players. One example are the computer lines after move 67 in game 6 of the last WC match Carlsen-Caruana. Some quotes regarding the winning lines suggested by computers:

Svidler:

> Even when I saw what the machine suggested was winning there I honestly don't think it was humanly possible to find it on the 10 minutes that Fabi had, and it's incredibly weird how the position is conceptually lost after Kg6.

Kasparov:

> The computer shows Black wins with 68..Bh4 here. But had Caruana played the incredible 69.Bd5 Ne2 70.Bf3 Ng1!! they would request metal detectors immediately! No human can willingly trap his own knight like that.

Svidler:

> A move that a human is more or less incapable of making

Grischuk:

> I would never even dream about Bh4

Carlsen:

> I’m not going to disagree with the computer, I just don’t understand it!

# Answer
> 5 votes
Yes, it's possible. See this article. The gist is, if for you're in a "draw and I win this tournament" situation, you would quite naturally play moves that might not be the best, but keeps the position simple and avoids tactical melees. You'd do this even if it reduces your chances to win the game. Conversely, if you're in a must-win situation, then you'll take chances and try to complicate the game even if they objectively weaken your position, because a draw is the same as a loss anyway. A computer on the other hand doesn't understand these things. It just makes the best moves.

Below is a quote from the article about this position, after 30...Bf6.

```
r6k/1p3Rpp/p2p1bq1/3N4/2P5/1P6/P1b2QPP/5RK1 w - - 0 1

```

> I showed the position to a number of players in Wijk aan Zee, and all gave me simple wins – for instance 31.Rxb7, 31.Rd7 or even 31.Rxf6. Remember, the first time control is looming and tournament victory is in grasp.
>
> So what does our hero play? 31.Qa7?!! “Fritzy!” squealed Anand and went into uncontrollable fits of laughter when he saw this and the following moves (I filmed his mirth and included it in my multimedia report in ChessBase Magazine 69). He and the other players immediately recognised the “hand” of the computer.
>
> If you switch on multiple-variation mode you will see that Fritz thinks 31.Qa7 is a tenth of a pawn better than the other alternatives. A computer program simply doesn't understand the difference between cast-iron moves that cannot fail, and a tight-rope walk on the edge of the precipice. I venture no human would undertake the latter course in the given tournament situation. Play through the continuation and judge for yourself.

# Answer
> 1 votes
Well... absolutely possible and common. Magnus Carlsen himself said *"I don't care"* on his very positive position in the last game of the 2018 WCC match. Did he offer a draw in a position that a chess engine can very likely to win?

Engine might play stronger chess, but if we don't understand how to do it, it's pointless. Sometimes we don't always make the best objective move. Carlsen did it to his last game. Kramnik tried several unsound openings this year.

# Answer
> 1 votes
Yes, it is very much possible and this is the very reason different openings exist!

Some examples:

* 1 e4 as White is suggested by almost all engines. However, some GM's and WC feel that e4 is too committal.
* Sicilian is almost never recommended by engines, whereas lot of GM's and WC's think that is the best way to equalize for Black. Engines usually suggest 1...e5 or 1...e6
* Engine evaluation of KID may not always be understable to humans. See here: https://en.chessbase.com/post/review-mihail-marin-winning-with-the-kings-indian

# Answer
> 1 votes
I would say definately yes. One example is the situation of a fortress. Even though one side is up in material the position is not winable. The engines can figure out that the fortress will not break in 10, 20 or whatever moves ahead but cannot figure out that it can **never** break! Then the evaluation function is obviously off and the suggested move is also off. Only a relatively strong human player can assert that it's a dead draw and reject the move and the line that follows.

# Answer
> 0 votes
To follow up on plus1's comment, consider things like

```
6kr/5b1p/2p3pP/rpPp1pP1/pP1PpP2/P3P3/1K6/8 w k - 0 1

```

as well. It is clear that if White takes the rook eventually the Black forces will break through yet many engines can't resist the lure of decreasing the points deficit.

---
Tags: engines, human-versus-machine
---


# Question
Title: Websites for creating tournaments with different starting positions
I'd like to create tournament for my students where I specify the starting positions.

Which websites allows users to create tournaments with different starting positions?

# Answer
> 5 votes
You can do this

**For free**

at https://lichess.org. Go to the "Play" tab, and select "Tournaments." Assuming that you have a lichess account, (*all they need for that is your e-mail, and they do not spam it*) you will see an option to create a tournament. Once you select that option, you will be able to specify the start position in the tournament (this position must be an opening with an ECO code).

If you wish to have *only your students* playing in the tournament, you can make the tournament private (password required to enter) and send the password to your students.

You can also play a game (not tournament) from *any legal position* (opening, endgame, middlegame, whatever) via the board editor, which is under the "tools" tab

---
Tags: tournament, online, websites
---


# Question
Title: CLI tool to let chess engines play each other
I'm looking for a command-line tool to let two chess engines play a game or a tournament against each other. The tool should support UCI and/or the xboard protocol and it should allow to save the game as a PGN.

I could only find GUI programs for that purpose. Aren't there any commandline tools that can do that job?

# Answer
Try cutechess, a reliable software.
> 2 votes

---
Tags: engines, computer-chess
---


# Question
Title: What rule changes are proposed to minimize the incentive to draw a game?
Many world champion games are drawn, and people in the general public think that is disappointing. Not to debate that opinion here, but the question seems to be out there. So what would a rule change look like to get rid of most of the drawn games in tournaments? Especially those agreed upon rather than those forced. What has been proposed?

What consequences would come from giving zero points to both players who draw? Or to punish the party who proposes a draw by a reduced score? Draws can be forced, and the players could "agree to force" a draw, so it's not apparent to me how it would work out.

# Answer
Possible solution for the World Championship match: always playing a tie-break before the classical phase.

In case, the main phase (12 classical games) is not drawn, the tie-break will be of no importance for selecting the world champion. Simply, the winner of the classical phase is always declared the world champion. Only if classical phase ends in a draw (6.0 – 6.0), the – previously played – tie-break is decisive.

The key idea is that a tie-break loser will have stronger incentives to play aggressively (offensively) than now. Already before the first classical game, he will be certain that without winning at least a single game out of 12, it is impossible for him to become the champion.

The incentives would be the strongest in the 12th game if after the 11 games the result is 5.5 – 5.5. To have championship chances, the tie-breaker loser will have to risk playing for a win.

The idea described here is a direct analogy to the solution proposed in the literature for soccer (see References below).

References:

Carrillo, J. D. (2007). Penalty shoot-outs: Before or after extra-time? Journal of Sports Economics, 8, 505-518. (link)

Lenten, Liam JA, Jan Libich, and Petr Stehlík. "Policy Timing and Footballers' Incentives: Penalties Before or After Extra Time?." Journal of Sports Economics 14.6 (2013): 629-655. (link)
> 4 votes

# Answer
Tried systems are to award 3 points for a win and 1 for a draw, not being able to offer a draw before move 30, and only being able to draw with the consent of the arbiter. There has been a long discussion about giving black 0.6 points versus white's 0.4, due the the advantage of the first move. There is also Fischer's suggestion of not counting draws in matches.

I have suggested on splitting the point in a ratio derived by the difference in rating. For people with \<= 75 points difference, the point is split evenly. 75-150, the point is split 0.6-0.4, weaker and stronger player respectively. There could also be a variance based upon which color was played. This should give the stronger player more incentive to play for a win, however it also gives the weaker player more reward for playing for the draw.
> 5 votes

# Answer
> So what would a rule change look like to get rid of all the drawn games in tournaments?

It wouldn't look like anything to do with chess because the question is one which displays ignorance of the laws of chess.

There are many situations where a draw is automatic -

1) Stalemate

2) Insufficient mating material

3) Five fold repetition

4) 75 moves without a capture or pawn move.

All of these instantly end the game according to the latest FIDE Laws of chess and in these cases the result is a draw.

> What consequences would come from giving zero points to both players who draw?

This shows tremendous disrespect to players who fight long hard games which end in draws because the players are evenly matched.
> 4 votes

# Answer
You can incentivize any behavior by providing the appropriate reward function. It is hard to select proper rewards (and even harder to persuade other people to adopt them). One example would be to give a slight edge for a win: 1.25 for win, 0.5 for a draw.

Another approach to make draws less likely is to start from a list of predefined very unbalanced positions. For example in checkers which had very high percentage of draws on the highest level, the game started not from the start but from a random position from a predefined list.
> 1 votes

# Answer
The 3-1-0 system (3 for a win, 1 each for a draw) has been used but IMO it unfairly penalizes the player of Black. At strong GM level it's difficult to win with Black if the opponent only wants a draw.

My suggestion is to modify the 3-1-0 method by giving Black 1.5 for a draw. This is equivalent to changing the normal 1-0.5-0 system by only giving White 1/3 for a draw.

It wouldn't be at all suitable for Swisses but for the invitational all-by-all events I think it would be very positive. There would be much more onus on players with White to play for wins and risk-taking players would be rewarded.
> 1 votes

# Answer
In Rudolf Spielman's book I have once read his proposal to introduce the following rules for scoring a single game:

1) mate to opponent: 7-0

2) opponent king left alone 6-1

3) stalemate to opponent king 5-2

4) draw by repetition 4:3 for black, 3:4 for white

With this scheme the score of each game is never equal for both partners so somebody always wins. In particular White is discouraged from a draw by repetition because he gets less than Black in this case.
> 0 votes

# Answer
One way to get rid of draws is to have all games be Armageddon games. Basically, when you play under these rules, a draw is counted as a win for one player, and the other player is given a time advantage as compensation.
> -1 votes

---
Tags: rules, tournament, draw
---


title: Sicilian Najdorf 6. Bg5 Nbd7 line

text:
# Question
Title: Sicilian Najdorf 6. Bg5 Nbd7 line
```
[fen ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 Nbd7

```

1) Why 6... Nbd7 is not played by many players? Why they prefer 6... e6 only? I could not get the answer for this. Requesting experts to answer this question with detailed explanation & examples. Thanks in advance.

# Answer
6.Nbd7 is played and often the lines transpose. If Black continues to try and avoid e7-e6, his position, though solid, is less aggressive than the other lines.

Fischer said something like:

> "The Sicilian is not a defense, but rather a vicious counter-attack!"

so with 6...e6 7.f4 Black has options like 7...Qb6 entering the Poison Pawn Variation, or 7...b5 entering the Polugaevsky Variation which are considered some of the sharpest variations in chess theory. Why spare White the worry of having to deal with either of these lines?

6...Nbd7 is playable and probably leads to equality as well but Black is delaying his counterplay if he avoids ...e6 for long. Some issues are that Black would like to play Qc7 and then has to worry about Nd5 when if Nf6xd5 exd5 results in a favorable structure for White.
> 0 votes

---
Tags: opening
---


# Question
Title: Finding a mating net in a RRN vs RRN endgame
This question relates to a game I played on LiChess (link), from which we have the following position:

```
[FEN "8/2rn4/2pN2k1/r1Pp2p1/p2P4/3KPP2/R7/7R w - - 4 42"]

```

In this position with white to move, I played 48. Rha1, eventually winning the a pawn. LiChess's version of Stockfish declared this a blunder and gives 48. Rah2 a score of +5.6. Playing it through, it even looks like white forces mate after giving many checks, although Stockfish doesn't claim this.

*Question*: In this two-rook and knight position, does 48. Rah2 lead to mate after a gajillion checks?

Ideally, it'd be nice if there was some way to understand the mate, as a human, if it exists.

# Answer
This is really a concrete-calculation question, to which you should find an answer yourself by either going through the obvious candidate lines or playing it out with the help of an engine. Your calculation techniques will benefit far more from that process, even if you don't find the answer, than asking for the direct answer.

In any case, clearly black is doing terribly poorly: there's no initiative, the rooks are completely out of play and stand defensively, and the king is quite isolated on `g6,` and even in the worst case scenario the passed `a` pawn is not hard to defend against. On the other hand, white's able to easily coordinate all 3 pieces for an attack on the king, either forcing material loss or checkmate. So the game's really lost even if you fail to find the mate, simplest being to mount an attack on the defense-free king on `g6` well caged thanks to the monster knight on `d6`. Focus on winning material first and then convert if the mate does not appear to be a trivial one. That said, the only way black can delay the imminent mate threat is to bring the knight into the defense, namely, `Nf6` which at least stops a rook landing on `h7` and secures some space for the king. As far as I see, even if black ignored the threat and just pushed the `a` pawn after `Rah2,` the cage around the king may be enough to force mate but it may easily be a case of mate in 12-15 moves1, which means, it's far simpler to grab material first and simplify the task before calculating for such forced lines.

Here's one line (among the various ways this can unfold) where black attempts a defense by bringing the knight, to which white can reply with a e3-e4 pawn push in order to advance a pawn to `e5` forcing the knight away from its "ideal" defensive post on `f6.`

```
 [FEN "8/2rn4/2pN2k1/r1Pp2p1/p2P4/3KPP2/R7/7R w - - 4 42"]

 1.Rah2 Nf6 2.Rh6+ {The immediate e4 may allow Rh7 for black, forcing the trade of a pair of rooks} Kg7 3.e4 {e5 is unavoidable, best black can do is to take once to at least free up the g4 square for the knight.} a3 {ignoring white's threat just to see what the mating net looks like} 4.e5 Ng8 5.Rh7+ Kf8 6.Rxc7  {Mate on f7 next} Ne7 7.Rxe7 Kxe7  {at this point, even if you don't see the mating pattern, you can simply win the a pawn first and then convert the game.} 8.Rh8 a2 9.Re8+ Kd7 10.e6+ Kc7 11.Rc8#

```

---

1: This is far too deep to calculate mentally, what players (at any level really) do in such a case, they simply go with the first few obvious moves (checks), moves they know cannot be possibly wrong, and after a while if it appears to have simplified then you can sit down and calculate a forced mate (assuming there's time) else you just have to be practical and go with the first best line you see, specially in such case where the position is trivially winning for white anyway.
> 3 votes

# Answer
**This is trivial calculation**, though I can see it tempting to just target a weak pawn -- it's the King we are after!

Phonon is correct in that you need to practice concrete calculation. But I disagree that the lines are too deep.

First: 1.Rah2 threatens Rh7 when R1h6 will be mate. Let's try to defend this straight forward threat:

Black moves his knight to allow his rook to defend h7: --Phonon's line of 1...Nf6 just loses a piece to 2.Rh6+ Kg7 3.Rxf6 followed by the fork on e8 (of course playing for more as in Phonon's line is better you don't need to calculate more when you already see a win), so how else can Black defend? -- 1...Nf8? 2.Rh6 and now the knight forks the King again!

It becomes easy to see that Black can't avoid these forks and mate at the same time. -- 1...g4 2.f4 doesn't change anything

**Supplemental:** To finish answering the direct question "Does it lead to mate": I will say it does not directly force mate. Black can jettison material to avert immediate mate.
> 1 votes

---
Tags: tactics, checkmate, calculation
---