# Question
Title: What are some good books or articles on how to play coffeehouse chess?
A coffeehouse style is what players who work hard to improve their skill at finding the objectively strongest moves in a position, having taken account of the objectively strongest moves available to the opponent, often disdain. Used by hustlers, by some recreational club players, and by many who play friendly blitz games, it is about playing what works in practice, in games with short or no time controls and which may be but are not necessarily played for money.

It includes playing moves that set traps that for some reason the opponent is likely to fall into. For example a classic example of a coffeehouse opening by Black is the Blackburne Shilling Gambit, 1 e4 e5, 2 Nf3 Nc6, 3 Bc4 Nd4. If White plays 4 0-0, 4 c3, 4 Nc3, or 4 Nxd4, he can get an advantage, whereas Black hopes that he will play 4 Nxe5, grabbing the pawn, after which he gets walloped by 4 ... Qg5, perhaps in the line 5 Nxf7 Qxg2, 6 Rf1 Qxe4+, 7 Be2 Nf3 mate.

But coffeehouse is not reducible to tactically trappy play and can be more subtle psychologically. For example if facing the line in the Alekhine Defence 1 e4 Nf6, 2 e5 Nd5, 3 c4 Nb6 White plays 4 a4, that move is not objectively weak but if it is played with a view to influencing Black to believe that White is weaker than he actually is, as if he were prone to lashing out aggressively with lots of pawn advances even when objectively unsound, it would be coffeehouse.

I would appreciate recommendations of titles not just on trappy coffeehouse openings, but on any aspect of how to play strong coffeehouse.

One book on coffeehouse is John Healy's *Coffeehouse Chess Tactics* (2010) and there is also John Emms's *The Survival Guide to Competitive Chess* (2005). What other titles are there?

# Answer
Maybe it's not exactly "coffeehouse" but Simon Webb's excellent *Chess for Tigers* is all about finding what works rather than looking for objectively best moves. From page 2 of the 2nd edition:

> Next time you sit down to play a match, ask yourself what is your aim in playing. Are you aiming to play the best moves? Or are you playing to win? There *is* a difference. Many players aim merely to play the best moves, objectively speaking. They never succeed, of course, but that doesn't stop them trying. But chess is not a science — it's a game, a struggle between two mortals who make mistakes, deceive themselves and each other, get tired, allow themselves to be distracted, and altogether have no hope of attaining perfection at the chess-board. If you want to become a Tiger, you must forget about playing the best moves and concentrate on winning.
> 2 votes

# Answer
Hikaru Nakamura wrote Bullet Chess; One Minute to Mate, perhaps not entirely what you had in mind. Ive not read it. Apparently, from Amazon reviews, some people liked it.
> 0 votes

# Answer
Any of the SOS books (Secrets of Opening Surprises) can be useful guides to lines effective in coffeehouse play.
> 0 votes

---
Tags: psychology
---


# Question
Title: Distracted by opponent's habit of spinning captured pieces
Many players have the habit of spinning and flipping captured pieces, e.g. Nakamura, Gelfand, Van Foreest, etc... However, when it is in my field of view, it distracts me and it brings me out of my concentration. Therefore, when playing a rated game and it's me to move, I would kindly ask my opponent to stop. And so far they always do, as they don't have the intention to distract me, it is just a habit of them.

I wonder, is there any mentioning of this in the FIDE rules?

What if my opponent would continue spinning a captured piece, ignoring my request to stop (which never happened so far)? Can I go to the arbiter?

Top players don't seem bothered, are they not distracted by it? Or is it *me* who is too easily distracted by it?

# Answer
> 25 votes
Article 11.5 of the FIDE Laws of Chess covers this:

> It is forbidden to distract or annoy the opponent in any manner whatsoever. This includes unreasonable claims, unreasonable offers of a draw or the introduction of a source of noise into the playing area.

If your opponent distracts you in this way and refuses to stop when you ask him then you should definitely call the arbiter. The arbiter will ask your opponent to stop this behaviour and will keep an eye on your game. If your opponent ignores the arbiter's instructions then the arbiter will penalise him.

Note that when top players do these potentially disturbing things they are careful to do so out of sight of the opponent so it does not actually disturb them. Gelfand spins his piece under the table where even he can't see it.

---
Tags: rules, fide
---


title: Backwards Chess Program

text:
# Question
Title: Backwards Chess Program
Is there a chess program where you can create a position and the program creates a game, expecting the best possible moves to get there, or the most common?

A problem I would see is some positions might require a terrible move to get there, or have really extensive games to get to that point.

I feel like this could create creative attacks

---

-Most common= most frequent move, such as how e4 is commonly responded with e5 even though stockfish rates c5 (Sicilian defense) as a higher value choice via the Aplha-Beta Pruning Algorithm.

-"Best" move= pretty much what stockfish/Komodo/ Houdini Would choose as their algorithm chooses the highest value, safe move, as their programs can go deeper than our abilities

# Answer
> 4 votes
I think this is doable. However, it will depend on the number of pieces in the required position. You see that many openings can be reached in multiple ways `(X,Y,Z,...) -> P`; where `X`, `Y` and `Z` are the sets of moves that get you from the initial position to the required position `P`.

This problem is NP-hard, because you can never know for sure which road was selected!

The best way for you is to study the positions of known games (which is most of the time is the case). Then search for \[1\] the game and play it back from the beginning.

---
Tags: engines, software, programming
---


# Question
Title: Longest number of moves that have been identical in two independently played games on record
Are there any recorded examples of two chess games that were identical till the end?

If the answer is no (which is most likely the case), what is the longest number of moves that have been identical in two independently played games on record?

# Answer
> 11 votes
**There are Several reasons for identical games:**

1. The fact that we databases and computers allows us to find the *best* move in known positions. (if both players knows the *theory* in the same level - it might lead to a known draw).

Hence some players might follow a known game between two great players, which might result with identical games.

2. The fact that there are known traps, might lead to to the same trap (when one player knows the *theory* and the other fall in the trap)

In this case, the game might end after the player fall in the trap.

3. In same cases, following a *theory* might lead to a lose as in the below story about Vishy Anand:

**Vishy Anand loses in 6 moves after following a known game**

```
[White "Zapata"]
[Black "Anand"]

[FEN ""]

1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.Nc3 Bf5?? 6.Qe2

```

**Anand resigns**

> The story goes: reaching the position after white's 5th move,Anand recalled the publication of the game Miles-Christiansen,in the Informator(a highly respectable chess journal),which went 6.Nxe4,Bxe4 etc....Impressed with the ease with which black had drawn in that game,Vishy decided to try it himself.But,after 6.Qe2,black just loses a piece.
>
> Now,how could both Miles and Christiansen have missed such an obvious move???? The answer is........they didn't!!**That game had been agreed drawn in advance**.Something the Informator had not revealed.At the board,Miles did see that Qe2 was winning,but remained the gentleman,and avoided playing it.It is said,that he did spend some seconds polishing the e2 square with his finger,untill Christiansen's face had the appropriate shade of red,whereupon Miles took on e4.

**Two Identical games**

Here you can find

1. Two identical games for the first 28 moves
2. 48 Moves - Both Haugen (2523)-Fernandez (2437), 2010, and Bross (2587)-Efremov (2574), 2011, reached the same position after 48...Qd7+:

This is my source for the below Answer, in this link you can find more identical games.

```
[Event "Uxbridge Int Alekhine"]
[Site "Uxbridge ENG"]
[Date "2010.02.17"]
[Round "8"]
[White "Rudd, J."]
[Black "Gormally, D."]
[Result "1/2-1/2"]
[ECO "B90"]
[WhiteElo "2286"]
[BlackElo "2479"]
[PlyCount "18"]
[EventDate "2010.02.13"]
[EventType "tourn"]
[EventRounds "9"]
[EventCountry "ENG"]
[EventCategory "2"]
[Source "Mark Crowther"]
[SourceDate "2010.03.01"]

[FEN ""]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 Ng4 7. Bc1 Nf6 8.
Be3 Ng4 9. Bc1 Nf6 1/2-1/2

```

Another Game:

```
[Event "ch-SUI"]
[Site "Lenzerheide SUI"]
[Date "2010.07.16"]
[Round "9"]
[White "Jenni, F."]
[Black "Kurmann, O."]
[Result "1/2-1/2"]
[ECO "B90"]
[WhiteElo "2542"]
[BlackElo "2449"]
[PlyCount "18"]
[EventDate "2010.07.08"]
[EventRounds "9"]
[EventCountry "SUI"]
[Source "Mark Crowther"]
[SourceDate "2010.07.19"]

[FEN ""]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 Ng4 7. Bc1 Nf6 8.
Be3 Ng4 9. Bc1 Nf6 1/2-1/2

```

Another Game:

```
[Event "Moscow Dvorkovich Memorial"]
[Site "Moscow"]
[Date "2009.09.11"]
[Round "4"]
[White "Gansvind, Valeriya I"]
[Black "Pisakov, Ilia"]
[Result "1/2-1/2"]
[ECO "B90"]
[WhiteElo "2226"]
[BlackElo "2331"]
[PlyCount "18"]
[EventDate "2009.09.08"]
[EventType "tourn"]
[EventRounds "13"]
[EventCountry "RUS"]
[EventCategory "4"]
[Source "ChessBase"]
[SourceDate "2009.11.03"]

[FEN ""]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 Ng4 7. Bc1 Nf6 8.
Be3 Ng4 9. Bc1 Nf6 1/2-1/2

```

---
Tags: records, famous-games
---


title: Effect of chess on work

text:
# Question
Title: Effect of chess on work
I'm a software engineer, mostly working from home so I get to schedule my time however I want. I noticed few things recently.

If I play more than 3 games a day, I can't work afterwords, I'd be mentally tired. I used to think that Chess makes me more productive and I kept playing every few hours a 5 min match to stay focused, but noticed that if the match is hard to win, I can't focus on work afterwards or if I was in time trouble.

I'm avoiding playing chess these days because of that and considering leaving the game. Is it just me or is what I described a common problem?

# Answer
> 3 votes
I have the same problem, and I think it's caused by two factors: 1- Bad time management. 2- Taking the games (win, loss) and rating seriously.

It happens to me that when I am winning and then I lose on time. I keep thinking of the game, even after I close the app. It's because I keep thinking that I should've played faster here or there. When I lose due to bad position or blunders, or if the position was equal, I run the analysis and keep thinking of the missed chances to win.

I did like what you did. It's been a week or so that I haven't played chess games. I only solve puzzles and do lessons. No online full games. This keeps my mind working (refreshed by the distraction of a different activity) and I don't have to think of what went wrong!

# Answer
> 1 votes
I like playing some 1 0 chess once in a while for often 20-30 minutes. I find it helps to actually relieve stress/nervous energy that I gathered when working.

It's obviously different for many people though. If you spend more effort on the game, it will tax you more. I haven't really heard of it exhausting an individual for the rest of the day, however.

# Answer
> 0 votes
If you play Classical Chess, try not to play more than one or two each day. They can be very exhausting.

Try to play Blitz or Bullet, these time controls tend relieve the stress out of you.

---
Tags: psychology
---


# Question
Title: Do different nationalities have "notably" different play styles?
In chess, noting the more common countries I've played (Indian Russia, Australia, France, US, China, Japan etc) I've noticed some similarities in their play style. Like how Japanese players, from what I've seen, play aggressive pawns; France and US play the more typical tactics, China doesn't play gambits, and overall isn't rich in strategy.

While these may just be coincidence, Is there enough similarity within a nationality that it's notable?

# Answer
> 7 votes
Consider this quote from wikipedia regarding the Soviet Chess School:

> The main contribution of the Soviet School of Chess was **not the style** of players but their emphasis on **rigorous training and study of the game**, i.e. considering chess a sport rather than an art or science.

Emphasis is mine.

Given that chess is taught as a school subject in Russia, then this points to there *not* being trends in chess style by country.

Moreover there seems to be little evidence that openings named after regions are done so because of their popularity there. If this were the case, then Scandinavians would tend to play the , which has a different style to the . In fact, the Scandinavian is called such because it was first seriously analysed by Scandinavian masters.

# Answer
> 1 votes
Interesting question, I've noticed that as well. In a way, german and english players for instance tend to play solid and wacky stuff respectively, like in soccer. Just kidding :)

Top GM of their countries play also an important role, `Trompovsky attack` has been popularised by John Nunn and other strong GMs, encouraging english chess school to adopt it. Strong german GMs like Jan Gustaffson usually play more solid openings. But there are exceptions of course.

# Answer
> 1 votes
Chess is a very internationalized game where geographical borders have a very limited impact on playing styles. Every strong player from any part on the world will have studied games from Capablanca, Euwe, Fischer, Kasparov and Carlsen, and that won't make their style more Cuban, Dutch, US, Russian nor Norvegian.

Moreover, in any big enough country, you will find very different players. Best Soviet grandmasters in the 60s where Stein, Petrosian, Smyslov, Taïmanov, Tal, Korchnoï and Spassky \[*edit: and Geller, and Keres, and Botvinnik, and so many... I should have chosen another country as example!*\]: but for the fact they all were super-strong players, it would be very hard to point any similarity in between their 'styles' (if such a thing even exists). If anything, their openings were very different. Later, Karpov and Kasparov were very different players too, etc...

For a while, an excellent book published in a certain language or an excellent trainer exercing in a specific area may have had an influence on the development of players in the given area and on their choice of openings: for instance, you would meet the Tarrasch defense more often in Sweden (a Gedeon Stahlberg's legacy) and the King's Indian more often in Yugoslavia (following Svetovar Gligoric's and Boris Ivkov's example). In our era of widespread information, however, I don't think that national borders have any significative influence.

---
Tags: style
---


# Question
Title: 100 Endgames You Must Know - What's the difference between 3rd & 4th Eds?
Does anyone know the difference between the 3rd and 4th edition of "100 Endgames You Must Know"? I just looked at the Table Of Contents and they are identical and random pages on Amazon look the same too. I would imagine there must be some new use of the new tablebases that were completed since 2012?

# Answer
De la Villa's "100 Endgames you must know", though apparently a good book seems to have been plagued by an abundance of typos and mistakes as detailed in this blogpost.

So although the culprit in this case has been the 2nd edition, maybe it does make sense to go for the latest edition. Here you can look at the errata page which presumably contains errors that have now been corrected, although as I mentioned some of these corrections probably already happened in the third edition.
> 2 votes

# Answer
I have the book on Chessable (popular site for reading chess books like this one):

> https://www.chessable.com/endgame-book/100-endgames-you-must-know/5193/

The difference in edition come from improved annotations and error checking. That's common for all books (chess or not). If you already have the 3rd edition, there's no point to get the newer edition.

Please note the edition is not specified in the screenshot because it's always the latest edition. I'd recommend to get an ebook version (e.g. Chessable or other publishers). New In Chess updates their ebooks for free, you will get a free update when they release the 5th, 6th edition etc.
> 1 votes

# Answer
Endgame books always **contain analysis mistakes**, and newer editions always **correct these mistakes**. So I would recommend to get up-to-date by buying the last one.

As you said, 7-men Lomonosov built since last edition, and probably 7-men tablebase revealed that some analyses wrong.

From erreta page: "On this Errata page we provide our readers with corrections in our books of analytical mistakes, or mistakes which might lead to misunderstandings ..."
> 0 votes

# Answer
I know this answer is coming late, but as someone who had the 3rd edition and upgrated to the 4th edition I can answer this definitely. The ONLY difference in the new edition is that diagrams have an indicator of who is to move, and glancing at the text below the diagram it's very easy to see who is to move if you can't already figure it out based on the particular ending you are studying, if you already have the 3rd and you want this "feature" just go through the book with a pencil and mark every diagram with W/B for who has the move, everything else in the book word for word is IDENITCAL, yes I went through each page and did not see ANY difference whatsoever. Those that said that updated versions where usually money grabs nailed this one completely. The publisher New In Chess was extremely deceptive selling this as a new version complete with a new book cover. This could have been done in a new printing, shame on New in Chess.
> 0 votes

# Answer
More often than not, edition differences are often just edits and re-phrasings. If you have the 3rd edition, then I would not fret about getting the 4th.
> -1 votes

---
Tags: books
---


# Question
Title: Why can't FIDE use a Non-Deterministic Gender Neutral Swiss Pairing system?
I have been following the controversy surrounding the pairings of Hou Yifan at the IOM chess tournament 2017. She was paired with 4 consecutive female players, this is following her last open swiss tournament outing in Gibraltar where she was paired with 7 female players from 10 pairings, including round 1 - 4 consecutive female-female pairing as in IOM 2017.

The question is can we not design a simple non-deterministic swiss pairing system that does not penalise the "outliers" of the female population of players? It is clear that rules make it more likely for Hou Yifan to be paired with women as there is an elo gap in mean the population of male elite GMs and female elite GMs and the lowest elo on the highest score and highest elo on lowest score pairing pattern used increases the likelihood of these gender-specific pairings. Any ideas?

Surely we can create opt out for gender pairings which occur consecutively?

# Answer
> 8 votes
The current algorithms are deterministic. I have no idea why you would want a *non*-deterministic algorithm. The advantage of the deterministic ones we currently use is that they can be easily done by hand (and were done by hand until quite recently), so if a TD changes them manually that can be detected.

Gender of the players is not an input to the algorithm at all. It does not play a role whatsoever.

Hou Yifan had a very unusual draw in this year's Gibraltar and the first four rounds of Isle of Man; but that's just a coincidence. Something like that has never been noticed with any other women or other tournaments or other years.

# Answer
> 3 votes
> Surely we can create opt out for gender pairings which occur consecutively?

Yes, we could. We can make whatever rules we like, after all. But I don't think we should.

Such a rule would have to come at the expense of some other pairing rule. We currently have rules that players cannot play each other twice, that players with equal scores should play each other, that colors should be equalized, etc. Which of the existing rules are less important than equalizing which gender a player will play?

Such a rule would also imply that playing females is somehow undesirable, or gives an inherent advantage or disadvantage compared to playing males with the same rating. I don't think these are views FIDE wants to encourage.

And any rule that makes things "non-deterministic" makes it harder for FIDE to verify that the pairings were not manipulated. (If we did have such a rule, why would it not be deterministic?)

> It is clear that rules make it more likely for Hou Yifan to be paired with women as there is an elo gap in mean the population of male elite GMs and female elite GMs and the lowest elo on the highest score and highest elo on lowest score pairing pattern used increases the likelihood of these gender-specific pairings.

First of all, people with "highest" and "lowest" scores are very unlikely to play each other. Perhaps you meant "higher" and "lower".

Second, there are pairing rules about minimizing the number of people who get the same upfloat/downfloat as the previous round, or two rounds ago, so while this may be a factor for some players, it won't happen every round, or even every other round.

Third, in both Gibraltar and Isle of Man, she did not float (in either direction) in any of the rounds, so this was pretty much irrelevant. It was sheer luck that she was paired with women.

# Answer
> 0 votes
> The question is can we not design a simple non-deterministic swiss pairing system that does not penalise the "outliers" of the female population of players?

What you are saying is sexist and very offensive. You are saying that when Hou Yifan is paired against other female players she is "penalised".

It is correct and fair that the pairing systems are required to be gender neutral.

Your suggestion that -

> Surely we can create opt out for gender pairings which occur consecutively?

offends against one of the basic principles laid down in the General handling rules for Swiss Tournaments in the FIDE Handbook -

> A. Pairing Systems
>
> ...
>
> 5 It is not allowed to alter the correct pairings in favour of any player.

---
Tags: software, tournament, fide, swiss-pairing
---


title: Facing its own weapons

text:
# Question
Title: Facing its own weapons
It's not a technically oriented question but rather a "psychological" one. Personally, I don't especially like to play against my own lines especially sidelines.

If I decided to play a precise line (ex : Malaniuk variation in the Scotch, but it does not matter here), it's because I consider it to be good, sound, enjoyable or whatever. But I have to play against it, I feel uneasy, like I'm playing myself. Am I the only one in this case ? Facing its own "weapons" could be an excellent way to improve though. What would be your take on this ?

# Answer
> 8 votes
I actually like playing against opponents who attempt to play the same way that I play with their color.

The important part however is to not follow your favorite lines to the very end. As you said, there is a reason you consider them worthwhile. Instead, use your knowledge about which moves you consider *unpleasant* when playing that variation. Chances are that your opponent, who apparently likes the style of a line you like, will dislike this deviation as well and will be just as uncomfortable as you. Keep calm, and you might be the one with the psychological high ground.

Playing against your own weapons also is a good way of sharpening them. Best case, one of your chess buddies plays the same variation. Then both of you can play a lot of practice games against each other starting with this variation with alternating colors and test possible ways your opponent might attempt to counter your strategy. I think you learn more by literally putting yourself in the opponent's skin and *really* trying to find winning moves against your variation rather than by just assuming their moves while exclusively playing your own side in training, which might lead to some bias ("hopefully he'll continue with this move in this line..").

# Answer
> 5 votes
You are not alone in this:

> **Don't play against your own weapons**
>
> Botvinnik said a player should devise an opening repertoire so that he doesn't have to face the same variations with White that he is prepared to defend as Black, and vice versa. In this way he avoids the psychological limbo of trying to beat his own ideas.
>
> Botvinnik followed his own advice. After adopting the Winawer variation as Black, he almost always played 3. Nd2 as White when facing the French. And when he devised his own line for the QGD for Black (1. d4 d5 2. c4 c6 3. Nc3 e6 4. Nf3 Nf6 5. Bg5 dxc4!?) he took care that when he was White he played 4. e3 or the Exchange Variation and never had to face the Botvinnik Variation.

Source: *The Wisest Things Ever Said About Chess* by GM Soltis

---
Tags: opening, psychology
---


# Question
Title: What happens if a strong chess engine plays with itself many times?
If a strong engine (eg. Stockfish) plays with itself many times (say, 100 times), what will be the outcomes in terms of the following:

1. What will be the proportion of draws? Will there be wins/losses? If so, what could determine wins? Will it tend to be predominantly white (because of opening advantage) or just random?
2. Will all the games played be along a narrow repertoire? Will there be diversity in games played?

# Answer
> http://tests.stockfishchess.org/tests

has information on **exactly** what you want. They are self-playing tests for improving the Stockfish code base.

The draw rate is roughly about **60% - 70%**. There're lots of wins and losses. I believe white has more wins but it's not shown on the page.

Chess engines aren't perfect, they do make mistakes. If SF makes a bad move at move 20, the same algorithm might find the win a move later (21) because it can search deeper and further.
> 15 votes

# Answer
With best settings and same opening moves, the results should be the same every time. Not very interesting. Only variation that might occur is if search depth vary due to time limit and random dips in processing availability.

With different predefined openings white is expected to win up to 6% more often (opening advantage). This might vary from engine to engine and restrictions put on that engine (search depth/time).

If you google it, there have been some Stockfish vs Stockfish games played and most of them seem to end in a draw. But I can't seem to find any extensive statistics.
> 3 votes

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


title: Will my rating increase?

text:
# Question
Title: Will my rating increase?
I just play 3 to 4 games in day(sometimes online) I am average chess player with rating 1400(rating is not fide rating. It is rating given by chess.com). Will my rating increase with time? Or I need to join classes or chess clubs to improve my game?

# Answer
If your rating has stagnated (not changed in a long time) then you need to change your approach. What you listed will definitely help. Even if your rating is still improving, those things will make it improve faster... or they may make your rating decrease initially as you try new things.

You can also learn by yourself without classes and clubs by using online and printed resources. However, an organized class may lead you to learn things you would not otherwise find on your own. Likewise, learning on your own will help you focus on the things you like most about the game. Do both.

At the end of the day - why do you play chess? If to have fun - why do you care if your rating improves? If to improve - why not invest yourself into classes, tactics trainers, and additional resources.
> 2 votes

---
Tags: rating, online-chess
---


title: About Alan Turing and chess

text:
# Question
Title: About Alan Turing and chess
I read Turing had some algorithm or method he could use to play chess 'against' this pen and paper algorithm assigning certain numerical values to each piece. Is this true? Is there a pen and paper algorithm one can use to play a kind of chess with oneself?

# Answer
Yes, he played a game against Alick Glennie, actually he created an algorithm based on mathematical calculations. Then he tried his algorithm using pen and paper to do calculations.

```
[fen ""]
[White "Alan Turing"]
[Black "Alick Glennie"]

1.e4 e5 2.Nc3 Nf6 3.d4 Bb4 4.Nf3 d6 5.Bd2 Nc6 6.d5 Nd4 7.h4 Bg4 8.a4
Nxf3+ 9.gxf3 Bh5 10.Bb5+ c6 11.dxc6 O-O 12.cxb7 Rb8 13.Ba6 Qa5
14.Qe2 Nd7 15.Rg1 Nc5 16.Rg5 Bg6 17.Bb5 Nxb7 18.O-O-O Nc5
19.Bc6 Rfc8 20.Bd5 Bxc3 21.Bxc3 Qxa4 22.Kd2 Ne6 23.Rg4 Nd4
24.Qd3 Nb5 25.Bb3 Qa6 26.Bc4 Bh5 27.Rg3 Qa4 28.Bxb5 Qxb5
29.Qxd6 Rd8 0-1

```

The main idea of algorithm is here:

1. Mobility: For the queen, rooks, bishops, add the square roots of the number of moves that the piece can make, counting a capture as two moves.
2. Piece safety: For the rooks, bishops and knights add 1 point if there is one defender and 1.5 if there is more than one
3. King mobility: For the king use the same method of scoring as for the piece, but do not count castling
4. King safety: Deduct points for the king's vulnerability, defined as the number of moves that a queen could make were it on the square of the king
5. Castling: add 1 point if castling is still legally possible after this move. Add another point if castling is immediately possible or if a castling move has just been made
6. Pawn credit: score .2 points for each rank advanced and .3 points for each pawn defended by one or more non pawns
7. Check and mate threats. Score 1 point for the threat of mate, and .5 points for a checkmaterial values used to each of the pieces were:pawn =1, knight=3, bishop=3.5 rook =5, queen=10
> 7 votes

# Answer
Yes, Turing created a "Paper Machine" along with David Champernowne in 1948 that they called "Turochamp". As far as I know he only played one recorded game with the system, against Alick Glennie (full game found here). There was only one recorded game against the Paper Machine because it took a very long time. Calculating one move without an electronic computer could take up to an hour.

You can read more about Turochamp here.

I have not found any source code for running Turochamp yourself, but I"m sure someone out there has coded it. For the 100th anniversary of Turing's birth Kasparov played a game against the Paper Machine, notes here.
> 5 votes

# Answer
Chessbase has made an implementation of Turing's engine available at the bottom of this post.
> 1 votes

---
Tags: engines, history, chess-variants
---


# Question
Title: How could I have played this opening better?
This was a recent game on chess.com. The "Maximum" analysis tool they have says my first mistake isn't until move 9, but I felt like I misplayed the opening even earlier. Indeed black's white squared bishop came back to haunt me. So: am I correct and if so, what could I have done better?

I include the entire game, complete with several embarrassing blunders (I'm still very new), for the sake of completeness. It may be worth nothing this was a blitz game.

```
[fen ""]

1. e4 b6 {I don't see this response to e4 often, but I figure it allows me to control the center better.}
2. d4 Bb7
3. Nc3 e6
4. Nf3 Nf6
5. e5 Nd5 {I instantly regretted my pawn push here since, in particular, it opened up the long diagonal for my opponent's white squared bishop. Better was maybe 5. Be2 or Bg5?}
6. Nxd5 Bxd5
7. b3 Bb4+ {I was preparing for 8. c4, which as foiled.}
8. Bd2 Nc6
9. a3 Bxd2+
10. Qxd2 Bxf3
11. gxf3 O-O
12. O-O-O Qh4
13. h3 d5
14. exd6 cxd6
15. Rg1 d5
16. Rg4 Qf6
17. Be2 Rac8
18. Rdg1 g6
19. h4 e5
20. dxe5 Nxe5
21. Rg5 Nxf3
22. Bxf3 Qxf3
23. R1g3 Qh1+
24. Rg1 Qxh4
25. Rxd5 Rfd8
26. Rxd8+ Rxd8
27. Qe3 Rc8
28. Rd1 Qf6
29. Qe4 Qa1+
30. Kd2 Rd8+
31. Ke2

```

I resigned here.

# Answer
> 5 votes
Some thoughts, mainly about your opening (to be fair, this game jumped right from opening to endgame in short order):

* Your first four moves are very good, taking control of the center while developing.
* **5. e5**. General rule of thumb: If you have pawns adjacent to each other and well-defended, you don't want to push one of them (*unless* you have a good reason! And achieve something concrete with it, say, if you had a bishop on g5). The reason is that by doing so you lose a lot of flexibility. As a pair on the same rank, the pawns control a line of squares of both colors, with no obvious opening to attack by your opponent while at the same time retaining the potential of two different pushes by yourself as soon as you see an opening in the opponent's structure in return. If you move one of them without a clear target, you weaken your own line of defense (as you noticed yourself, the bishop diagonal is now open) and you also commit yourself to one attacking angle, which means that your opponent now doesn't have to worry about the other as much anymore (you cannot easily play d5, so your advance has essentially come to a halt and is not much of a threat to him anymore). Bg5 is a much stronger move here, Bd3 is fine too (development + protection of e4).
* **6. Nxd5.** Actually makes a lot of sense, despite moving a developed piece a second time, as it offers a way to "repair" your pawn structure in the center. A pawn on c4 makes it only half as bad, since then the e4 pawn has regained hope of being mobile again with the support of his neighbour.
* **7.b3.** But then you fail to execute that plan. Why not play 7. c4 straight away? The pawn will be defended adequately by your bishop on f1 and scare back the enemy bishop with a gain of tempo. Why do you need more support of c4? The only way black can attack it once more is by ...b5, and he cannot do so because of Bxb5.
* **8. Bd2.** Makes sense.
* **9. a3.** Allows Black to play 9...Bxf3 10. Qxf3 Bxd2+ and you are forced to retake with your king and strand it in the middle of the board behind a less than optimal pawn structure. Lucky that he played it the other way around.
* Moves 10 & 11 are obvious.
* **12. O-O-O.** Not the best choice, in my opinion. Your kingside might look just as weak as the queenside, but the doubled pawn actually offers some interesting possibilities, too. Many pieces have been exchanged already, so you don't actually have to worry about your king's safety after castling short: Bg2 fills the gap nicely (and can exploit the long diagonal where Black is actually weak now that his bishop is gone) and Black cannot bring in more pieces other than the queen anytime soon. Your f-pawn can support e5 from f4 to keep the center closed so that this stays this way and it may even attack on f5 in the future. You, on the other hand, might be able to use the half-open g-file to threaten his king. Black's counter plan will be to open files for his rooks. As this will happen on the queenside or center, castling long happens to have moved your king into future lines of fire. h1 would have been a much safer place to hide.
* **13. h3.** Kinda unnecessary at this point in time, but it's alright, you want to make the rook more mobile.
* **14. exd6.** Obviously, following my commentary on move 12, I don't like this move either. En passant looks fancy and all, but I think your strategy at this point should be to keep the center closed and use your (small, but hey) advantage on the kingside before he can break through on the queenside.
* Rest of the game, in short, as it doesn't really concern the opening anymore: After opening the center, his rooks can join the fight, and your inferior pawn structure quickly shines through. Castling long proves to be absolutely inefficient in terms of king safety because of said whole-y structure.

# Answer
> 0 votes
The game was totally correct but after the move 22..Qxf3 you could play 23.Rxd5 your f2 pawn is defended and opponents one pawn will down , and you could control the d file for that time which is very good . The opening was reasonable , but i think you need to prepare middlegame. For advice you can see the games of karpov and carlsen. sites : http://www.chessgames.com/perl/chesscollection?cid=1011420 ; http://www.chessgames.com/perl/chesscollection?cid=1034176 etc.

---
Tags: opening, positional-play, 1.e4
---


title: FEN notation problem

text:
# Question
Title: FEN notation problem
See image: Why does this FEN code display incorrectly (it should describe the Portsmouth gambit)?

# Answer
> 2 votes
OK I seem to have solved this. In the .fen file do not use pgn tags! Then the FEN code displays correctly. Of course FEN positions can be added or used in PGN files and then the pgn tags are needed\]

See image..hope this may help others

---
Tags: fen
---


# Question
Title: Looking for a Gata Kamsky quote - 'you must be playing a different kind of chess'
I remember a really interesting moment from the coverage of one of the past US chess championships (probably 2015 or before). Kamsky had just finished his game and was asked by Maurice Ashley for his opinion on one of the games in progress. So Maurice starts with how White has all this advantages, more space... certain squares etc. And Kamsky instantly replied

> **you must be playing a different kind of chess**. white has no plan at all. black just goes... \[some moves\] and that's it

(of course I might have black and white mixed up above)

It was a striking illustration of how immediate and accurate the evaluation of an elite grandmaster can be. Does anyone remember this at all? I am trying to find the video clip or failing that, the position that the guys were discussing. I am pretty sure it was in the uschesschamps website at the time, but not anymore.

# Answer
I remember this - it was an impressive moment. I don't remember who the players were, but the game was probably from the Open section. Vague recollections of proposed kingside maneuvers for Black, involving ...Qg8-h7 or something likewise extravagant. I don't remember the result of the game or if Kamsky's ideas were played. And unfortunately, most of the videos on the CCSCSL livestream channel from before 2014 seem to be gone.
> 1 votes

---
Tags: grandmaster
---


title: Checklist before you make a move

text:
# Question
Title: Checklist before you make a move
What is the checklist that you generally follow before you make a move?

I would generally look first for forcing moves (checks/captures), then moves that give me some positional edge.

It would be good to know what good players think during moves.

# Answer
1) Did my opponent’s last move contain a threat? Is the threat real and something I need to respond to? Or am I able to ignore that move and continue with my plan?

2) Do my pieces have sufficient protection? Do I have a piece that is hanging? Does my opponent have an under-protected piece?

3) Is my king safe? What about the opponent’s king? Can I take advantage of my opponent’s king by, for example, preventing him from castling?

4) Did my opponent’s last move prevent the threat posed by my previous move?

5) Do I still need to develop my pieces?

6) Can I bring my rooks to an open file or in general, make them useful? Can I double up rooks on an open file? Do I need to still open files for my rooks?

7) Does my opponent have any weaknesses? What are the targets I should considering attacking (undefended pieces, under-protected pieces or squares, open king, etc.)?

8) How can I attack the target(s)? Any other weaknesses that can be exploited? What’s the plan?

9) After looking away for a few seconds and revisiting the position with a completely clean, unbiased mindset, does the move I am about to make appear to be a mistake? Am I hanging a piece? Am I falling for a forced checkmate? Did I analyze all forcing moves (checks, captures, and threats)? Are my thoughts consistent with what I am calculating?

Taken from ChessUniversity.com, but is taught to students everywhere.
> 9 votes

# Answer
There are not so many books that talk about the thought process of selecting a move.

There is a section about this in Michael de la Maza's book *Rapic Chess Improvement: A Study Plan for Adult Players* (Everyman Chess, 2002). Below is a summary. (See also this PDF.)

1. Make a physical movement. (This may sound strange, but Michael de la Maza found this important for himself.)
2. Look at the board with "chess vision". (The book describes exercises to develop your "chess vision". See also Microdrills to Improve Your Chess! on Chess.com.)
3. Understand what your opponent is threatening.
4. Write down your opponent's move on your score sheet.
5. If the opponent makes a serious threat, then respond. If not, calculate a tactical sequence. If no tactical sequence exists, implement a plan:
    * Improve the mobility of your pieces.
    * Prevent the opponent from castling.
    * Trade off pawns.
    * Keep the queen on the board.
6. Write down your move.
7. Imagine the position after the intended move and use "chess vision" to check the position.
8. Make your move and press the clock.

Dan Heisman also describes a thought process in his book *The Improving Chess Thinker*:

1. Write down your opponent's move.
2. Ask yourself: what are **all** the things your opponent's move does? Look at checks, captures and threats, in that order.
3. What are all the positive things you want to do? This includes potential tactics.
4. What are all the candidate moves which might accomplish on or more of your goals.
5. Which of these candidate moves can you reject immediately because they are not safe? (Find checks, captures and threats that defeat the move.)
6. Of the final candidate moves, which one is the best you can find in a reasonable amount of time?
> 4 votes

# Answer
1) Checks

2) Captures

3) Threats (I'm threatening to check, capture, tactic like fork, skewer etc. on my next move or the move after)

4) Stop my opponent's plan

5) Improve my position

After everything else but must always be done is **blunder check**! Even a check or capture can be a blunder. The saying "Patzer sees a check, patzer plays a check" is only about the patzer who forgot to blunder check his move. The first step to stop being a patzer is the final blunder check.

Some players would say that I have "4) Stop my opponent's plan" too far down and it is more important.
> 3 votes

# Answer
The best & shortest checklist before making a move is

* Find out which opponent's move is most aggressive and coming in my territory or crossing half of the board.
* Sometimes when you miss the above a volley of moves come in and seizes your initiative and render it to your opponent.
* From your side you can find out that any of your piece needs protection and king is safe.

You can make a long list for yourself but practically it not feasible sometimes to remember all the steps but the above is the best suited for all formats of the game even in blitz.
> 1 votes

---
Tags: best-practice
---


# Question
Title: Black's reply against anti-Grünfeld (3.d5)
This is not the most famous anti-Grünfeld out there, but the move `3. d5` is a bit unconfortable for a Grünfeld player, at least for me.

Main moves are `3...Bg7` and `3...c6` challenging the `d5` pawn right away. But I don't see a clear follow-up in either case. What would you recommand considering I'm not a King's indian player ?

```
rnbqkb1r/pppppp1p/5np1/3P4/2P5/8/PP2PPPP/RNBQKBNR b KQkq - 0 1

```

# Answer
In Volume 1 of his high-quality series on the Grünfeld for black, GM Avrukh recommends 3....b5!?, "playing in the spirit of the Benko Gambit". On page 6 of the PDF excerpt, you can find his analysis.

However, this may not be to everyone's taste. Instead, he also gives the line 3....c6 4.Nc3 cxd5 5.cxd5 d6 6.e4 Bg7 etc... "with equal chances". To me, this seems a good way to play: black has several ways to develop his pieces on the queen side and to create counterplay (e.g. Nbd7-c5, e6) and it is not necessary to memorize any complicated lines.

With 3.d5 white indeed avoids any Grünfeld structures, but it is relatively harmless and black can develop quite harmoniously.

```

      [StartPly "5"]

      [FEN ""]
      1.d4 Nf6 2.c4 g6 3.d5 c6 (3...b5) 4.Nc3 cxd5 5.cxd5 d6 6.e4 Bg7 7.Nf3 O-O 8.Be2 Nbd7 9.Be3 Nc5 10.Nd2 e6

```
> 10 votes

---
Tags: opening, 1.d4, grunfeld-defense
---


# Question
Title: Is there a rule that doesn't allow adjustment during the opponents time?
While playing a tournament, I adjusting my pieces several times during my opponent's time. He claimed a win for the same. Can anyone explain how this rule works and why is it there?

# Answer
I think this FIDE rules section explains that:

> Article 6.2
>
> d. Only the player whose clock is running is allowed to adjust the pieces.

According to Article 4.2, a player should announce *"j’adoube"* (I adjust) **before adjusting pieces on the board**, providing only the player having the move may adjust one or more pieces on their squares (i.e. player in turn with clock still running).

In actual games usually the arbiter only issues verbal warning about adjusting pieces only in respective player's turn. But keep in mind you should avoid distracting the opponent, i.e. obstructing their view on the board when it's opponent's turn to make a move, since Article 4.8 applies if a player decides repeating disruptive behavior from his/her opponent, without announcing to adjust the pieces first:

> A player forfeits his right to claim against his opponent’s violation of Articles 4.1 – 4.7 **once the player touches a piece with the intention of moving or capturing it**.

Related issue:

Adjusting in ones turn only
> 9 votes

# Answer
In your case, the relevant rule is here :

> 4.2
> Provided that he first expresses his intention (for example by saying “j’adoube” or “I adjust”), only the player having the move may adjust one or more pieces on their squares.
>
> \[...\]
>
> 4.8
> A player forfeits his right to claim against his opponent’s violation of Articles 4.1 – 4.7 once the player touches a piece with the intention of moving or capturing it.

As for why, I believe that adjusting your pieces while your opponent is thinking is very disruptive, especially if it happened several times during the game. It just breaks his focus. During your opponent's turn, you should let him focus as much as they want. It could also be very unfair if you adjust your pieces while your opponent doesn't have much time, since you are using their time at their detriment.
> 6 votes

---
Tags: rules, fide
---


# Question
Title: Learning steps of a non-professional or play-for-fun player
Let's say I already know the rules of the games. What would be the next thing I should focus on? And then? Learning the most common openings? Unbalances?

I learned to play chess as a kid, played once in a while back then but then I have hardly played in 20 years. I've started to play again, and I'd like to improve. I don't want to be extremely good and I don't have a lot of time to invest, I'd just like to achieve a decent level and enjoy playing.

I'd also appreciate a couple of book recommendations, pre-intermediate level.

# Answer
> 4 votes
Go to your local chess club. They will match you with opponents of an appropriate skill level. In addition, there will be people there willing to help you improve.

# Answer
> 2 votes
Obviously, simply **playing the game** is the best way to enjoy it and, at the same time, fill your brain with the patterns you need to improve.

If you want to speed up that improvement process without spending a lot of time and while still having fun, the most efficient things are **tactics puzzles** (there are tons of apps or websites out there) and **joining a club** (hopefully there's at least one in your town).

**Tactics** are widely considered to be the most important topic to practice at the beginner to intermediate level in order to get better at the game. Doing puzzles can be done very time-efficiently by using a couple of spare minutes here and a couple of spare minutes there (e.g while waiting for the bus) - you don't have to allocate special "training time"! At the same time, they will pump happiness hormones into your brain by using the psychology of reward stimuli (most apps/sites use some sort of point system to show your progress).

Visiting a **club** on the other hand will use up some hours per week at a specific time slot - but most clubs try to place their meetings at an employment-friendly time in the evening, so it shouldn't interfere too much with your daily routine. And, of course, meeting with other people is the best way to have fun and enjoy the game! You can also learn a lot by having better players comment on your play. This sort of advice generally is less "complete" than the coverage a book might offer, but it will be specifically tailored to *your* needs. And it will be a lot less dry, so more of it will actually stick in your memory (properly working with a chess book takes a lot of time - that you might not have - and can quickly develop into a chore).

# Answer
> 1 votes
To complete other answers, I'd avise you to play **15 min games or longer time control**, avoid blitz at the very beginning. Playing blitz is a very good way to practise opening though, and you speed thinking, but not right now.

Speaking of openings, choose an opening that suits your style (be it a `d4` or `e4` opening) and stick to it. Play **something sound that you intend to play in the long run**. For example, a lot of players try to dodge the Sicilian playing McDonnell Attack or Grand-Prix (a bit better than the latter). Those are not totally unplayable but you won't learn a lot and will be crushed against stronger players. **You shoud avoid the most theoritical openings**, because you'll spend most of you time and efforts remembering moves (or findind them over the board) rather than playing chess.

If you are a `d4` player, you'll learn (anyway!) the `Queen's gambit declined`, to which you can add the `Trompovsky` (very interesting opening). If you are an `e4` player and you're afraid of the open Sicilian, give a try to the `Rossolimo`.

As black, against `e4` and if you're willing to play the Sicilian, I'd recommand the `Taimanov`. Against `d4`, it's hard to tell, you have a bunch of choice. The `Nimzo` is very interesting as well, theoretical of course but maybe not as much as the Grünfeld or King's indian. But once again, it depends on your style.

# Answer
> 0 votes
Here are some recommendations for your limited time: Solving tactic puzzles is the best way to improve. There are online sources for this but books with the best bang for your buck are: "1001 Winning Chess Sacrifices and Combinations" and "1001 Brilliant ways to Checkmate" both by Fred Reinfeld. Then you need to learn strategic basics so read "My System" by Aron Nimzowitsch. And of course you need basic endgame knowledge so "Basic Chess Endings" by Reuben Fine Memorizing openings isn't going to make you a good player. You can watch videos on youtube for openings but with your time constraints I would not recommend opening books. I do recommend you get a book of games written by the player, some world champion that you like.

---
Tags: learning
---


# Question
Title: How should I analyse my game to get better?
I've been playing chess for a while, but very casually. I just joined a chess club and played my first tournament game. Not having used a chess clock before, or ever having had to record my moves made things interesting!

I really want to get better and I've heard I should be analyzing my games. Other than stepping through them and figuring out if I should have done something differently (given I lost, probably), is there something specific I should be doing?

This is my game from tonight, any ideas/analysis would be very welcome.

```
[fen ""]
1. e4 c5
2. d3 Nc6
3. Nf3 e5
4. Nbd2 Nf6
5. c4 Be7
6. Nb3 O-O
7. Be3 d6
8. h4 h6
9. Qd2 Ng4
10. O-O-O Nxe3
11. fxe3 a6
12. d4 exd4
13. exd4 cxd4
14. Nfxd4 Ne5
15. Qf4 Qc7
16. Nd2 b5
17. b3 bxc4
18. Bxc4 Nd3+
19. Kb1 Nxf4
20. g3 Ne6
21. Nd2f3 Rb8
22. Rc1 Qa7
23. Nc6 Qe3
24. Nxe7+ Kh8
25. Rhf1 Qxe4+ {I realized this was a mistake as soon as I made it}
26. Rc2 Nd4
27. Ne1 Nxc2
28. Nxc2 Qxc4
29. Ng6+ fxg6
30. Rxf8+ Kh7
31. Kc1 Qd3
32. Rd8 Bf5
33. Ne1 Qb1+
34. Kd2 Rxd8 {i resign}

```

# Answer
> 1 votes
## Opening

I feel that you are getting lost in the English Botvinnik system, seeing as you form the Botvinnik pawn triangle (c4-d3-e4) but then your piece placement is off (e.g. O-O-O instead of O-O). I suggest you visit my answer to Suggest a line for a player who does not want to be dragged into the Sicilian for more information.

Also, try not to move the same piece multiple times in the opening, as 6. Nb3 isn't constructive. I would try 6. Be2 and 7. O-O with a safe but cramped game.

## Material

You concede the bishop pair (half a pawn) with 9. Qd2 instead of 9. Qc2.

The move 15. Qf4 is the start of your tactical woes. This square should set off alarm bells because of both the potential for a knight fork and pin (...Bg5 may become playable). I would have looked at 15. Kb1.

## Tournament etiquette

Comfortably using notation and the clock comes with practice, but I don't understand why you carried on playing after 18...Nd3+.

# Answer
> 1 votes
You can go over your game(s) with a chess engine to see what tactics you missed. You should also find a better player to look at your games so they can tell you what you are missing strategically. Finally, you could compare your opening moves to a database to see what other players did in that particular line.

---
Tags: analysis, learning, beginner
---


# Question
Title: Why can't the king castle in this position?
In a video I'm watching (requires register), it has this setup.

```
[FEN "r3k2r/pp1qn1pp/2p2p2/8/3P4/5N2/PP2QPPP/2R1R1K1 b kq - 0 1"]
[startflipped ""]

```

The instructor says:

> The king cannot escape, he cannot castle kingside or queenside, because of the white's pressure on e7 \[...\]. Black wants to escape this pressure by castling by hand.

I don't understand why can't black castle. It won't castle from, through, or into check. Why is it?

# Answer
> 42 votes
**Executive summary:**

Black actually can castle, but if he does castle he will lose the knight and the game (due to material loss).

**Detailed answer:**

Black and White have equal material.

* The black knight is protected by two pieces: the king and the queen.
* The black knight is attacked by two pieces: the queen and rook.

If the king castles, the knight will be protected only by the queen, and White will be able to win the knight which will lead to a big material advantage: a knight, which is worth about 3 points.

"Castle by hand" (meaning moving the king and the rook over several turns until they reach a castle position) will allow Black to keep protecting the knight. (E.g. By moving the king to F7 to protect the knight, followed by a rook to E8, etc.)

# Answer
> 1 votes
There is one possibility when castling would be illegal - if king has moved earlier in the game - then the move would be illegal.

---
Tags: rules, castling
---


# Question
Title: Website to practise thematic games [blitz]?
As stated in the title, are there any websites out there to play thematic games in Blitz (or quick time control) ? The idea is to practise a specific opening, starting from a precise position (arising after the exchange Grünfeld for example). I know a french website where it's possible but for corresponding games only. Thanks in advance.

# Answer
> 2 votes
Lichess has what you are looking for:

But you may have to check out when a specific opening theme may be scheduled in their tournament table. Also Lichess has a feature to start your own thematic tournament at any time of the day, but attracting players to the custom tournaments typically does not work.

# Answer
> 0 votes
Chess24.com used to do this - https://chess24.com/en/read/news/new-thematic-tournaments . I don't know if these tournaments are still running.

---
Tags: opening, websites
---


# Question
Title: Queens Gambit Accepted 3rd move Side Lines (White)
What are rationals/inherent preferences behind the following novelties performed by White? I'm open to those to either logically deduced them or explain the deviated lines through experience/practice playing them.

### The traditional line:

```
[FEN ""]
1.d4 d5
2.c4 dxc4
3.Qa4+ Bd7
4.Qxc4 ...

```

### Novelty 1:

```
[FEN ""]
1.d4 d5
2.c4 dxc4
3.Bf4!?

```

### Novelty 2:

```
[FEN ""]
1.d4 d5
2.c4 dxc4
3.Nd2!?

```

### Novelty 3:

```
[FEN ""]
1.d4 d5
2.c4 dxc4
3.b4!?

```

# Answer
> 10 votes
**Short answer**

3.Qa4+ and 3.Bf4 are reasonnable enough moves but not dangerous for Black.

3.Nd2?! and 3.b4? are very dubious.

**1. "Traditional line"**

I don't know why you name it that way, 3.Nf3 or 3.e4 are much more common than 3.Qa4+. By the way your "novelties" are certainly not that "new" either.

The idea of 3.Qa4+ is to regain the pawn at once. Its minus is that the queen goes out too early and will lose some tempi later on. Note that beside 3...Bd7, 3...Nc6 is possible too.

**2. "Novelty 1"**

3.Bf4 is just a developing move, so it cannot be too bad. However, it doesn't adress the main issues in the QGA (fight for the center, for the light squares, for the Pc4...), so it should be pretty harmless for Black after, say, 3...Nf6 4.e3 c5!?, or 4...Bg4!?, or simply 4...e6 followed by a6,c5 in traditional QGA-style.

**3. "Novelty 2"**

I suppose 3.Nd2?! aims at taking back on c4 with that knight. Fair enough, but it becomes a real (double-)gambit after 3...Qxd4!? 4.Nf3 \[or 4.e3 Qd7 5.Bxc4 e6 and White doesn't have enough for one pawn.\] Qc5, and White has to prove his compensation. If Black is less adventurous, 3...Nc6 4.e3 e5 should already be advantageous for him: he has more influence in the center and White hasn't got his gambitted pawn back yet.

**4. "Novelty 3"**

3.b4? sets a record: There is no faster way to give your opponent a passed pawn after only 5 plies. It also doesn't develop, doesn't make a threat and weaken your queenside.

If Black takes en passant, White will get a bit of compensation for his pawn but probably not enough. If black just develops with 3...Nf6 or 3...e6 (already hiting b4!), he enjoys a great position with as much of an advantage as you can dream for on move 3 as Black. The solid 3...c6 planning either 4...a5 attacking the weakness on b4 or 4...b5 securing an extra protected passed pawn also looks logical to me. 3...e5!? is a more aggressive option, and a tempting one as well since 4.de5 Bxb4+ 5.Bd2 Qd4 6.Bxb4 Qxa1 is probably just winning for Black.

Maybe White's idea is the trap 3...Nc6?! 4.d5 Nxb4?? \[even here, 4...Ne5 should be okay.\] 5.Qa4+ winning the knight, but well, that's just a cheapo and once Black avoids it he can be very happy.

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


# Question
Title: Can black make any progress in this end game?
I have been analyzing this endgame for a while now, but I can't seem to make any progress. The engine evaluation is -2.5, but I'm wondering if this is one of those weird evaluations that is wrong because black can never win.

Black to move

```
8/8/8/1q4p1/p6k/B1R4P/K7/8 b - - 0 1

```

# Answer
> 4 votes
It does look like a fortress. After 1...Qe2+ 2.Bb2 Qd2 White can wait with Ka2-b1-a2 or Bb2-a1-b2 depending on where the queen sits.

Black cannot bring the king to d4 because of discovered checks, so the best try seems to be to travel to d5 and play a3 when the pieces are Qd2, Bb2, wKb1. Then Rxa3 Kc4 prevents the rook from coming back to c3 because of Qxc3 simplifying to a winning pawn ending.

Alas, White still can play Bc1 Qg2 Re3 Kb4 Ra3 and wait with Ra3-e3-a3.

I believe it is a draw.

# Answer
> 0 votes
It would be perpetual since white can keep the rook on the 3rd file and guard it with the bishop, your best bet is to hope they blunder, which isn’t likely

# Answer
> 0 votes
I checked the tablebases, and removing the a3 pawn is a win for black, while removing the a3 and b5 pawns is a draw.

I ran it through a couple of engines for a while, starting with Qd5+, Kb2, Qd2+. It did not appear to come up with anything.

---
Tags: endgame, fortress
---


# Question
Title: Bronstein timing vs. Simple Delay, Is there a formal definition of Bronstein Timing that specifies whether the increment should be added initially?
There seems to be some controversy on whether there is really any practical difference between Bronstein timing and Simple Delay timing. By "Bronstein" and "Simple Delay" I'm referring to the timing methods described in this Wikipedia Article

Now I think the fact that the two timing methods are functionally equivalent is proven quite convincingly in this YouTube video. Note that the DGT clock shown using Bronstein timing starts by adding the delay to the initial time before counting down and that is an important factor in making the two timing systems equivalent. Note that the Wikipedia definition I linked to earlier doesn't make any mention of whether the delay interval should be added to the time at start.

I've also noticed that other clocks that implement Bronstein timing don't automatically add the interval time at the start. For example, the Garde clock shown in this YouTube video. (Note, jump to 2:37 to see the clock started)

In the case of a clock like that, I believe the two timing systems aren't functionally equivalent in that the Bronstein timer would always run out sooner by the amount of the delay. And in the case of a secondary time control, that would accumulate so that it would be shorter by 2xDelay.

So here is my question, I can't find any definitions of Bronstein timing that specify whether the delay should be added to the start time as DGT has implemented it and I can't find the text of David Bronstein's original proposal of this timing method to see if it specified how the start time should be handled. To me the DGT way seems more correct, but if it isn't really specified then I guess both clocks could be considered correct as it is ambiguous how it should be handled. I also couldn't find a FIDE rule that specifies how Bronstein timing should work.

So does anyone know of a formal specification that addresses the starting time issue?

Also, If anyone has experience with other clocks that implement Bronstein timing other than the DGT and Garde clocks I mentioned, do most clocks add the delay from the start like the DGT or just start counting from the set time like the Garde?

# Answer
> 2 votes
The Fide Laws of Chess state the following:

> 6.2. b. The time saved by a player during one period is added to his time available for the next period, except in the ‘time delay’ mode.
>
> In the time delay mode both players receive an allotted ‘main thinking time’. Each player also receives a ‘fixed extra time’ with **every move**. The countdown of the main time only commences after the fixed time has expired. Provided the player stops his clock before the expiration of the fixed time, the main thinking time does not change, irrespective of the proportion of the fixed time used.

I'm under the impression that the literal interpretation is the correct one, and the delay should be added to the start time.

Technically, The Youtube video does not show whether the first 5 seconds of the first move are the delay (making the time control essentially 79 minutes 55 seconds for 30 moves etc. with delay starting from the first move) or not (the delay in the first move is completely skipped).

In addition, the video does not show what happens when the 30 move mark is reached, but the clock seems to be counting moves, and I assume it will add the extra time automatically, and I don't see any reason it won't also add the delay at the end of the 30th move.

---

While this was not your question, I think it's worth mentioning: The only other section related to this topic I could find in the Fide Handbook is in the section "Standards of Chess Equipment and tournament venue for FIDE Tournaments":

> 5.1. (b) The display at all times should show the time available to complete a player’s next move.

so it appears to me that in terms of the Fide rules, the correct method of showing time is the Bronstein method, as opposed to the delay method.

# Answer
> 1 votes
So, I noticed this as well. I recently purchased a DGT3000 to replace my Saitek Game Clock II that had finally died. With Bronstein timing, the Saitek did not add the increment to the initial time control (i.e. at move 0), but the DGT3000 does. This seemed odd to me. I play a lot of 2-12 Bronstein games (2 minute games with a 12 second increment). I programmed one of the DGT's manual setting slots for a Bronstein 2-12 control and I was surprised to see 2 minutes and 12 seconds on my clock at the start of the game.

I've been a USCF rated player since the 1970s. I'm also a certified tournament director, and I've never seen a clock that handled the Bronstein control like this. Yes, I understand the rules stated above 6.2. b and 5.1.b. However, the problem in adding the delay to the initial time control violates Bronstein's own rule that the bonus can never increment the time to more than what was on the clock at the beginning of the move. Finally, I would also point out that Bronstein controls seen on the online sites such as FICS, etc. don't do this.

Fortunately, for the DGT, you can get around the problem by setting the initial control down by the increment. In other words. a setting of 1:48-12 in reality yields the 2-12 game I'm after on the DGT.

# Answer
> 0 votes
According to this Wikipedia article (a different article than was linked in the question...), the Bronstein time adjustment is always added back at the end. The first clock I had that implemented this was the original Saitek digital clock, and it implemented it this way (same as the other clocks that were described in the question).

---
Tags: rules, chess-clocks
---


# Question
Title: Game engine versus engine from a given position
I use Fritz8SE , which allows the following options :

* You can let play two engines against each other a normal game.
* You can setup a position and let one engine play out the position.

What I would like to do :

> Setting up a position and then let play two engines against each other, ideally with different PLY's.

Does anyone know whether this is possible ? And if yes, how ?

# Answer
> 1 votes
It’s also possible within Chessbase’s Fritz UI, you just save the desired sequence of moves as a database and then define that database as the opening database for the engine match.

# Answer
> 1 votes
**ANSWER**:

> Yes. Here's how:

1. Download Arena Chess Engine GUI
2. Ensure Athena has the Chess Engines you desire installed
3. If not - Check Best Free Chess Engines
4. Download Stockfish
5. Download other desired Chess Engine
6. Configure Chess Engines in Arena
7. Load both Chess engines
8. Set up position
9. Example for setting up and conducting a tournament in Arena can be found here

---
Tags: engines, fritz
---


title: Top-rated players in each style

text:
# Question
Title: Top-rated players in each style
Who are top-rated players (with 2600+ ELO) who are most notable in each of following styles?

```
Aggressive
Positional
Calculating
Technical
Practical
Intuitive

```

# Answer
As addressed in my answer to What is chess style?, there is a website called ChessPersonality.com which gives a list of styles alongside suggested openings and top players you may want to study.
> 1 votes

---
Tags: style
---


title: Fastest King vs King endgame

text:
# Question
Title: Fastest King vs King endgame
What is the fastest possible game that ends in a King vs King endgame? Please post a game and tell me the number of half-moves you've achieved. By some simple logic, I can prove that this number is greater than 32 half-moves. There are 30 pieces to be captured, and the first capture can only be made on the 3rd half-move or later.

An example of such a game could be this:

```
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. e4 d5 2. exd5 c6 3. dxc6 Qa5 4. cxb7 Qxa2
5. bxa8=Q Qxa1 6. Qxa7 Qxb2 7. Qxb8 Qxb1 8. Qh5 Qxc2
9. Qxh7 Qxc1+ 10. Ke2 Qxd2+ 11. Kf3 Qe1 12. Qxh8 Qxf1
13. Qxg7 Qxg1 14. Qxg8 Qxh1 15. Qxf7+ Kd7 16. Qxf8 Qxh2
17. Qxe7+ Kxe7 18. Qxc8 Qxg2+ 19. Ke2 Qxf2+ 20. Kxf2 Kd6
21. Qd7+ Kxd7
1/2-1/2

```

achieving the result in 42 half-moves.

# Answer
This is a famous task, originally tackled by Sam Loyd and only improved a century later. See http://www.chessvariants.com/problems.dir/twokingstask.html, which gives the refinement by Ponzetto:

```
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1.e4 d5 2.exd5 Qxd5 3.Bd3 Qxa2 4.Bxh7 Qxb1 5.Bxg8 Qxc2 6.Bxf7+ Kxf7 7.Rxa7 Qxc1 8.Rxb7 Rxh2 9.Rxb8 Rxg2 10.Qxc1 Rxg1+ 11.Rxg1 Rxb8 12.Qxc7 Rxb2 13.Qxc8 Rxd2 14.Qxf8+ Kxf8 15.Rxg7 Rxf2 16.Rxe7 Kxe7 17.Kxf2

```

For reference, here's the original Loyd solution:

```
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. c4 d5 2. cxd5 Qxd5 3. Qc2 Qxg2 4. Qxc7 Qxg1 5. Qxb7 Qxh2 6. Qxb8 Qe5 7. Qxc8+ Rxc8 8. Rxh7 Qxb2 9. Rxh8 Qxa2 10. Rxg8 Qxd2+ 11. Kxd2 Rxc1 12. Rxg7 Rxb1 13. Rxf7 Rxf1 14. Rxf8+ Kxf8 15. Rxa7 Rxf2 16. Rxe7 Rxe2+ 17. Kxe2 Kxe7

```

\[ **ETA:** Incidentally, while the linked article leaves it as an open problem, it seems like it would be a very straightforward task to show that 16.5 is optimal; at least at first glance I don't see any lines that have captures by both sides on all four half-moves in moves 2 and 3, which would imply that some form of 'off move' along the lines of White's 3. Bd3 is a strict necessity within the first few moves. \]
> 14 votes

# Answer
**41 Half moves, not a real game**

The first possible capture is indeed on the third half-move. After that, a perfect game would be purely captures. By counting the moves which don't involve a capture, you can show how close to a perfect king v king you got. Giving check is bad, unless the opposing king can take a piece while moving out of check (unlikely, if none of the pieces are moved)

The following is a game I created to challenge this puzzle, and it includes 11 half moves which do not take a piece. The other 30 half moves are all captures. My solution is one half move faster than the OP's proposed solution (42 half moves):

```
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. e4 d5 2. exd5 Qxd5 3. Qh5 Qxg2 4. Qxh7 Qxh2 5. Qxh8 Qxh1 6. Qxg8 Qxg1 7. Qxg7 Qg6 8. Qxf7+ Kd7 9. Qxf8 Qxc2 10. Qxc8+ Kd6 11. Qxb8 Qxb2 12. Qxa8 Qxa2 13. Qxa7 Qxa1 14. Qxb7 Qxb1 15. Qxc7+ Ke6 16. Qxe7+ Kxe7 17. f3 Qxc1+ 18. Kf2 Qxd2+ 19. Be2 Qxe2+ 20. Kg3 Qxf3+ 21. Kxf3

```

**Now in 36 half moves:**

```
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. c4 d5 2. cxd5 Qxd5 3. Qc2 Qxa2 4. Qxh7 Qxb2 5. Qxg7 Qxb1 6. Qxg8 Rxh2 7. Rxa7 Rxh1 8. Rxa8 Rxg1 9. Rxb8 Rxg2 10. Rxb7 Rxf2 11. Rxc7 Qxc1+ 12. Kxf2 Qxd2 13. Rxc8+ Kd7 14. Qxf7 Qxe2+ 15. Kg3 Qxf1 16. Qxf1 Kxc8 17. Qxf8+ Kd7 18. Qxe7+ Kxe7

```

By using the queens and rooks I was able to take pieces from either side of the King. When only using the queen, I had to move the queen across to the other side without giving check, so using rooks aswell removed this problem.
> 9 votes

# Answer
Francois Labelle has studied this as part of the more challenging problem of finding a unique proof game which ends with KvK. Labelle's site contains a wealth of computational chess results, including massacre proof games, u.e. proof game problems where nearly all the moves are captures.

He found one proof game leading to KvK in 19.5 moves, and has certainly got all the (non-unique) 16.5 games. A minor point worth noting is that any solution cannot end with a capture of a minor piece, or a forced capture, because there would be a prior dead position.

His Stratgems 58 article on unique bare king proof games is on his site. Here is the full solution, taken from the Die Schwalbe Chess Problem Database.

1.c4 e5 2. Qb3 Qh4 3. Qxb7 Qxh2 4. Qxb8 Qxg1 5. Rxh7 Rxb8 6. Rxg7 Rxb2 7. Rxf7 Rxa2 8. Rxd7 Rxd2 9. Rxa7 Kxd7 10. Rxc7+ Kd6 11. Rxc8 Qxg2 12. Rxf8 Kc5 13. Rxg8 Rxg8 14. Bxg2 Rxg2 15. Nc3 Rxf2 16. Kxf2 Kxc4 17. Kf3 Kxc3 18. Bxd2+ Kxd2 19. Ke4 Kxe2 20. Kxe5

```
[Title "François Labelle, P0330 StrateGems (58), 6/4/2012"]
[FEN ""]

1. c4 e5 2. Qb3 Qh4 3. Qxb7 Qxh2 4. Qxb8 Qxg1 5. Rxh7 Rxb8 6. Rxg7 Rxb2 7. Rxf7 Rxa2 8. Rxd7 Rxd2 9. Rxa7 Kxd7 10. Rxc7+ Kd6 11. Rxc8 Qxg2 12. Rxf8 Kc5 13. Rxg8 Rxg8 14. Bxg2 Rxg2 15. Nc3 Rxf2 16. Kxf2 Kxc4 17. Kf3 Kxc3 18. Bxd2+ Kxd2 19. Ke4 Kxe2 20. Kxe5

```
> 4 votes

---
Tags: problems, records, mathematics
---


# Question
Title: Maximum number of pieces on board in dead position
It is possible in a chess game to have a dead position in which both players have all eight pawns, one bishop, and a king--20 pieces total. If the two players' pawns are interlocked in "zig-zag" fashion and each player's bishop is the same color as his pawns, each player's army will be forever stuck behind his own wall of pawns, with no way to ever reach anything on the other side.

```
[FEN "4kb2/8/1p1p5/pPpPp1p1/P1P1PpPp/5P1P/8/4KB2 w - - 0 1"]

```

What is the largest number of pieces that can be on the board in a legally-reachable position such that either:

1. The side on move has at least one legal move, but no sequence of legal moves would produce checkmate.
2. It would be possible to play an arbitrary number of legal moves, but no sequence of legal moves would produce checkmate.
3. No legal sequence of legal moves would produce checkmate or stalemate.

I would guess that the first of those might be possible with as many as 28 pieces on the board, but most escape-proof positions rely upon immobilized kings to block opposing pawns, making it hard to allow anything other than pawns to move safely. What are the actual limits?

# Answer
**EDIT** 30-Dec-2023: added the R(1,D) position with 32 units. So Challenge 1 is now completely resolved.

Apologies that the first few lines are a bit theoretical. I reach the actual chess as soon as I can! :)

**Living & dying moves**

In a position, if there are no legal moves, then the game ends immediately: in **checkmate** (if check) or **stalemate** (if no check). Otherwise, there is at least one legal move. Then we can describe each legal move as either **living** (if there's a checkmate still possible after playing it) or **dying** (if there is no checkmate anywhere ahead in its game tree). Quality of play is not a consideration: all sequences of legal moves are valid.

**Living & dead positions**

Under FIDE Laws, the game ends immediately in **Dead Position (DP)** if there's at least one legal move, and *all* of them are dying. A position with a living move we call **living**.

So there are four kinds of position: checkmate, stalemate, dead & living. These are exhaustive & mutually exclusive. In particular, stalemate & dead position are disjoint. (This last point wasn't obvious to me at first, but clearly it's the intention of the FIDE Laws.)

| Summary |
| --- |
| A living move gives a living position or checkmate. |
| A dying move gives a dead position or stalemate. |

**Zombies**

From a DP, the moves aren't actually played (except over-the-board by accident or from ignorance sometimes: see http://wismuth.com/chess/illegal-moves.html). Such legal but unplayable moves are called **zombie moves**. Similarly, a legal but unreachable position is called a **zombie position**.

*Formally the game terminates as soon as DP is reached.* There is no arbiter involvement needed. I have spoken with the Head International Arbiter at the time (Stewart Reuben) and the Rules Committee member who invented the DP rule (Igor Vereshchagin), who confirmed. When they designed the rule as a replacement for draw by insufficient material, they were aware of the potential for entertainingly complex positions, but reckoned (correctly I think) that almost all practical situations encountered would be very simple. The rule seems to have bedded in well in the last 25 years.

Zombie moves are hypothetical, because in all such positions the game has already finished. But in fact you *need* hypothetical moves, in order to explore the game tree and determine if a position is living or dead in the first place. So this "walking dead" concept is well-defined and it's also fun.

**Avoiding circular definitions**

Sometimes, people overload the term "illegal move" to mean "zombie move", as in Francois Labelle's page linked above. A lot of the time such usage doesn't matter, but it can be confusing. Since DP is *defined* based on the FIDE Laws concept of legality, any redefinition of legality would be circular. So I prefer the perhaps more pedantic terms introduced above. Note: this is just terminology, it doesn't affect the underlying logic.

**The three challenges**

OP proposed an excellent challenge for each of three increasingly restrictive categories of DP, rephrased as:

1. any DP,
2. DP, and some sequence of zombie moves can avoid stalemate indefinitely,
3. DP, and no sequence of zombie moves can reach stalemate.

A difficulty is that solutions for 3. can have so many units that perhaps nothing new that can be added by loosening the game-end criteria in 2. To avoid overshadowing in this way, I suggest that we modify the categories, to make them mutually exclusive:

1. DP, and all sequences of zombie moves end in stalemate.
2. DP, and some, but not all, sequences of zombie moves end in stalemate.
3. DP, and no sequence of zombie moves ends in stalemate.

(For these purposes, we can ignore Draw by Threefold/Fivefold Repetition & 50/75 move rules. A subject for another day, maybe...)

**Types A, B, C & D**

To construct a position with certain properties, it's often easier if one player is already in check, or if we're given who has the move. So retroanalysis enthusiasts often sub-divide Task Records into various types:

* **Type B** = no check, but we are told who has the move (e.g. White here). (In theory, retro-logic might tell us who is on the move without being told: this is so-called Type A, but this doesn't seem applicable for this question. We would treat it as a special case of Type B.)
* **Type C** = one player is in check.
* **Type D** = either player might be legitimately be on the move. We require that both sides satisfy the category requirements (1., 2. or 3.)

Therefore we treat each of these Types separately here. Note that if R(n,X) is the maximum number of pieces for Category n with Type X, then R(n,B) \>= R(n,D).

**Summary of Results**

What records have been achieved so far?

| Record | Modified Challenge 1 | Modified Challenge 2 | Modified Challenge 3 |
| --- | --- | --- | --- |
| R(n,B) | 32 ID01 | (26) | (29) |
| R(n,C) | 32 ID02 | 29 ID04 | 30 ID06,ID07 |
| R(n,D) | 32 ID03 | 26 ID05 | 29 ID08 |

In this table, ID numbers reference the problems below. Any number in brackets is implied by R(n,B) \>= R(n,D).

Are these records the best possible? R(1,B) = R(1,C) = R(1,D) = 32 are definitely unbeatable, but all the other records may well be improvable.

**At last: some chess!**

Here are all the constructions that drive this table:

```
[title "ID01 R(1,B)=32, White to move, A.Buchanan"]
[fen "bqn1KN2/rrk1pB2/nb1pPp1p/p1pP1PpP/PpP3P1/1P2N1R1/4Q3/1R4B1 w - - 0 1"]

```

Note, with White to move there is no e.p. possible since Black's last move could not have been g7-g5. Bf8 would have been captured at home, but we know it's still on the board.

This position would not work as Type D because with BTM it's stalemate/living (depending on e.p.) with BTM. It wouldn't work as Type A because BTM is reachable.

See also two other capture-free positions that work as R(1,B).

```
[title "ID02 (R1,C)=32, A.Buchanan"]
[fen "bqn1KN2/rr2pB2/nbkpPp1p/p1pP1PpP/PpP3P1/1P2N1R1/4Q3/1R4B1 w - - 0 1"]

```

This is just a minor variation, retracting 1 single move from ID01. The same can be done in both of the other two R(1,B) positions linked to.

```
[title "ID03 R(1,D)=32, A.Buchanan & J.Coakley"]
[fen "qrkn3n/rb1p1p1p/p1pPpPpP/PpP1P1P1/1P6/KRB5/BRN2N2/bQ6 w - - 0 1"]

```

BTM: 1. ... Bxb2+ 2. KQRBxb2=. WTM can't relieve the looming stalemate. 20+1=21 legal but unplayable moves.

```
[title "ID04 R(2,C)=29, J.Coakley, The Puzzling Side of Chess 127, 2016"]
[fen "rnb1K1Qk/rb1pN1p1/p1pP2P1/P1P5/5p1p/4pP1P/q3P1BR/5BNR w - - 0 1"]

```

Mandatory 3 captures yields position in which stalemate is optional.

```
[title "ID05 R(2,D)=26, J.Coakley, The Puzzling Side of Chess 127, 2016, version"]
[fen "rnb1K1k1/rb1p2p1/p1pP2P1/P1P5/5p1p/4pP1P/4P1BR/5BNR w - - 0 1"]

```

This is the position 3 mandatory single moves after ID04. It can be reached with either side on the move.

```
[title "ID06 R(3,C)=30, example 1, A.Buchanan"]
[fen "qrn1KRRB/brk1pPN1/1p1pPp1p/1b1P1P1P/Pp6/1Pp5/2P5/N5bB w - - 0 1"]

```

One approach...

```
[title "ID07 R(3,C)=30, example 2, A.Buchanan"]
[fen "brn1KRRB/brN1pPN1/1bkpPp1p/p1pP1P1P/q1P5/1P6/1Q6/b4B2 w - - 0 1"]

```

...and another, achieving the same record.

```
[title "ID08 R(3,D)=29, A.Buchanan"]
[fen "qrn1KRRB/brk1pPN1/1p1pPp1p/1P1P1P1P/1p6/1Pp5/2P5/N5bB w - - 0 1"]

```

One move after ID06, but it can be reached with either player to move.

```
[title "ID09 Challenge 1, Type B, 31 units, White to move. Last move?, A.Buchanan"]
[fen "brnk1N1B/qnb1pBR1/rbKpP3/p1pP2NQ/P1P2p2/1p3P1p/1P5P/5R2 w - - 0 1"]

```

**Bonus! Last move?** Finally, here is a runner-up R(1,B) position in which additionally one can determine the last move. It costs a unit, so is not reflected in the table above, but nevertheless is interesting to illustrate the frequent involvement of en passant in critical DP situations. As with ID01, this can neither be Type A nor Type D.

Black's last move must have been b4-b3. If the prior position was dead, the game would have already terminated. So White's move before that was a2-a4 or c2-c4, and Black chose not to make the en passant capture, which would have kept the game alive. No en passant convention is required here: a double pawn move by White is the only way the game could have reached the current position without dying already.
> 15 votes

# Answer
I've come up with 23, in the following position, with promotions:

```
[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[FEN "nb2k3/2p5/1pP5/1Pp5/2P1p1p1/3pPpPp/3P1P1B/4KNBN w - - 0 1"]

```

*
> 12 votes

# Answer
Funny task. I think I'm still pretty far from the maximum, but here is a suggestion with

**23 men**:

```
[Event "?"]
[title "Challenge 3, 23 units"]
[FEN "NRN1k1bn/QRKpPp2/PPpP1Pp1/2P3Pp/7P/8/7B/8 w - - 0 1"]

```

**With black to move, an almost-dishonest trick to reach 25**:

```
[title "Challenge 3, BTM, 25 units"]
[FEN "BRN1Nkbn/QRKpPp2/PPpP1Pp1/2P3Pp/7P/8/1r6/B7 b - - 0 1"]

```

**27 with promoted units**:

```
[title "Challenge 3, Check, 27 unit, including promoted"]
[FEN "QNBk1bnr/RBpPpKbr/PpP1Pp1p/1P3P1q/6P1/8/1R6/b7 w - - 0 1"]

```

*explanation*: This is a dead draw because after the forced moves 1.gxh5 Bxb2, White could only play his king back and forth on f7 and g6 while Black's bishop explores the bottom half of the board. wRb2 could be replaced by a wB or a wN (or a wQ with obvious adjustment of the nature of the upper-left-corner stranded pieces), or even by a fourth bB while preserving legality. This is so many "degrees of freedom" that I strongly feel that 27 is not the maximum, and someone will soon come up with (at least) 28...

*edit*: indeed, Laska just scored a pretty 28 (or even 30 with "the trick").
> 11 votes

---
Tags: theory, problems, draw, records, dead-position
---


# Question
Title: Capture towards the center vs. undoubling
There is a spoken advice to capture with the pawns always towards the center. This situation let me think for a while. Is undoubling here not better?

# Answer
> 9 votes
In this particular position both ...ab6 and ...cb6 are reasonable.

Generally speaking I would prefer to take toward the center because the doubled pawns are not weak at all when they have neighbours and the enhanced control of the center might prove useful.

Here however ab6 has the minus that it allows White counterplay thanks to the outside passed pawn after a4-a5.

The evaluation of this position will depend on Black breaking through or not on the kingside, with ...Rf3 or ...g4. My intuition is that White should be able to hold. If that's correct, the best choice might very well be to limit counterplay with 1...cb6. But once again, this is merely due to the specifics of this particular position, and not because undoubling would be better than taking toward the center in general.

# Answer
> 2 votes
Here all is about whether white a-pawn will be strong passed pawn or weakness on semi open file. Possible undoubling is just a side effect of more important consideration. If you can blow the kingside, make your center as solid as possible and wait a3 will become a serious weakness with white pieces tied to defense. If you can't, you will have to deal with huge distraction problem on the a-file, forcing you to leave attacking position. My first idea was clearly cxb6 but it's better to ask the engine :-)

# Answer
> 1 votes
I think Olivier is right to prefer axb6. The drawback of allowing White a potential passed pawn is not serious, unless it occurs at some late stage of an endgame. Until then it is just a backward pawn on an open file. But Black also has a great position on the other wing. A Fischer block with Rf3 must be taken seriously.

In the general situation, you should ask, why are doubled pawns weak? Sometimes because they cannot protect each other, sometimes because the square ahead is open to blockade. Neither applies here, but they would exert great control over the center. Whether you are playing with doubled pawns or against them, you have to "accentuate the positive". Remember that anything that cannot be attacked is not weak.

---
Tags: strategy, pawns, captures, doubled-pawn
---


# Question
Title: Opening classification and transpositions
Positions in an opening can often be reached in a variety of (meaningful) ways, i.e. by *transpositions*.

When classifying chess games (e.g. in databases or books) by , are there rules or other guidelines which of these transpositions to pick?

# Answer
Your question has two different nuances, that is, how to classify an opening and how to classify a game.

The Encyclopedia of Chess Openings' only aim is to classify the first moves of a chess game, it does not concern itself with how the game develops nor further transpositions. Even if a widely known position is reached after an unorthodox choice of moves, the ECO will classify the opening according to these first moves. A comprehensive list can be found both in 365Chess and Wikipedia, the first provides easy access to the variation in question and the second provides the name and some contextualization for the variation.

While the ECO has not an analogous encyclopedia for complete games, the widespread and common way of treating them in the literature is to find the last instance of a known tabiya and consider the game under its umbrella. This ignores the concrete opening, which is often useful since the game may be a relevant addition to the theory on that position, and thus the particular move order leading to it is irrelevant.
> 1 votes

---
Tags: opening, transpositions
---


# Question
Title: Can it be proven that 11. 0-0-0+ is legal in this position?
Because the chess site this was on takes its puzzles from real games and gives the move numbers, potential solvers knew that the following position was reached after exactly 10 moves by each player.

```
[fen "2bk2nr/p1p2ppp/2p5/2p5/2P1P3/2N5/Pr3PPP/R3KB1R w - - 0 11"]

```

> Given that information, can one prove that 11. 0-0-0+ in the above diagram is legal?

(i.e., that neither the white King nor the Ra1 has moved so far)

It seems to me like that's not enough total moves for white to have spent two
moves "shuffling", but I can't come up with any proof or a counterexample-game.

# Answer
> 6 votes
Reasoning by hand about proof games is fine, but is more fun for positions which have been designed by humans to be solvable and to contain interesting features. Automatic verification is standard for all but the most complex of compositions, and is normally done by specialized engine, of which there are several available for free online.

IMHO, the best proof game engine for OP's position is Natch. Running for 49.03 seconds, it found 2493 "solutions" for how to reach the position in exactly 10.0 moves. None of them contained the strings e1, a1 (or 0-0-0!) and so there is no way that White could have lost castling rights in the prior play.

Notes:
(1) The way that Natch reports consolidates results to reduce the length of the report, so there are rather more than 2493 actual proof games, but that doesn't affect the conclusion.
(2) What about other engines? Popeye is not the most performant for this kind of position, and Euclide would have terminated as soon as it found that there wasn't a unique solution. But both are excellent engines.

# Answer
> 20 votes
Ok after playing around with a couple of lines, I finally found one line that shows it's still perfectly legal to play long castles for white at move 11, here it is:

```
[Title "possible 11.O-O-O+"]
[StartFlipped "0"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.e4 e5 2.Nf3 Nc6 3.c4 Rb8 4.d4 exd4 5.Nxd4 Bc5 6.Nxc6 dxc6 (6... bxc6 7.Be3 d6 8.Bxc5 dxc5 9.Qxd8+ Kxd8 10.Nc3 Rxb2 11.O-O-O+) 7.Qxd8+ Kxd8 8.Be3 b6 9.Bxc5 bxc5 10.Nc3 Rxb2 11.O-O-O+

```

Added another continuation, taking on c6 with the b-pawn, same position results and same number of moves needed!

To conclude, because I reached the given position in exactly 11 moves, and did not play any redundant moves (e.g. Nf3 then back to Ng1 again), it means that all the played moves were necessary, their order can be different, but point is there was no spare move to use and destroy white's castling (e.g. an impossible scenario would be black exchanging queen on d1, Kxd1, then black plays Kxd8, and white goes back to e1, but that took up 2 more moves than the line I showed, so impossible to reach the position you're looking for in 11 moves after such line)

Long story short, castling is perfectly possible here, and in 11 moves black could not have done anything to prevent us from castling and still manage to reach the final position we want. Interesting post by the way, +1.

Alternatively one can also just look at the final position and count the necessary number of moves, that must take place for this position, I elaborate: have the final position in mind: let's take black's point of view: Pawn moves needed to obtain the final position:

1. e5
2. exd4 (why black has to take on d4 and not white on e5 is explained in the diagramm below)
3. bxc6 or dxc6
4. b6 or d6
5. bxc5 or dxc5,

Development moves:

6. Nc6 (to be captured on c6, otherwise there cannot be a pawn on c6 and not have knight on b8)
7. Bc5 (otherwise c5 pawn impossible)
8. Rb8 (otherwise Rxb2 never possible)

Remaining necessary moves: Queen d8 capture and pawn b2 capture:

9. Kxd8
10. Rxb2

And we find ourselves at the 11th move again, where all we did was just consider the most straighforward ways our pieces could end up where they are in the shown puzzle.

Let's see if we reach the same position via another path, showing why exd4 is the fastest way to reach the final position:

```
[Title "Why black must take on d4 and not white on e5:"]
[StartFlipped "0"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.e4 e5 2.Nf3 Nc6 3.c4 Rb8 4.d4 Bc5 5.dxe5 Nxe5 6.Nxe5 d6 7.Nc6 bxc6 8.Be3 Rxb2 9.Bxc5 dxc5 10.Qxd8+ Kxd8 11.Nc3

```

Here we are at move 11 and we still have to play Nc3... clearly because we played 2 knight moves for black.

Finally let's demonstrate why in the fastest path to the final position, white has to be taking on d8 (queen exchange) and not the other way around:

```
[Title "A line white cannot castle but the final position cannot be reached within the 10 required moves (so impossible for our purposes)"]
[StartFlipped "0"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.e4 e5 2.Nf3 Nc6 3.c4 Rb8 4.d4 exd4 5.Nxd4 Bc5 6.Nxc6 dxc6 7.Nc3 Qxd1+ 8.Kxd1 b6 9.Be3 Kd8 10.Bxc5 bxc5 11.Ke1 Rxb2

```

We lost 2 king moves(capture on d1 then back to e1) for white in this line, hence the Rxb2 only happening at the 11th move.

So it was shown that the only line leading up the the final position within 10 moves, is one where white still must be able to castle.

**EDIT:** A summary of the discussed elements in the comments:

The proof presented in this answer is purely deduction based, in the sense that the simple fact of having reached the position in exactly 11 moves without having made any redundant (or insensitive to the position) moves, implies that 11.O-O-O+ should be legal without exception.

*What does redundant mean here?* "Redundant moves": here, are defined as moves that do not bring us any closer to the final position, or would even deviate us from it. For example playing Nf3, then back to Ng1, would be redundant. Playing Be2 then back to Bf1 would be redundant, and so on.

Point being, in any variation, you may come up with, that would take away white's castling rights, will imperatively entail redundant moves, that will in turn delay reaching the final position by a couple of moves. (As an exercise, try some of your ideas, it is interesting, and see how many moves it takes you.)

Looking at such problem from a combinatorics point of view, may be possible, but would be too complicated as we're looking at a depth of moves(tree lines) resulting from 11 moves. Instead, like most chess puzzles, one has to look at it from a purely heuristic point of view, and find the right ideas that would go in the direction of proving the question at hand. Finally, in chess, one usually has an easier time looking for counter examples(proof by contradiction), which is why it is encouraged to look into some of the lines on your own.

# Answer
> 4 votes
We can deduce nine moves that white absolutely had to make to get to this position.

* At least three moves were required to put white's pawns and its queen's knight there (3 total)
* Either the c- or d-rank pawn was captured after it moved. That's another move (4 total)
* The pieces captured on c5 and c6, whatever they were, needed at least two moves to get there. That's four extra moves. (8 total)
* If the piece captured in c6 isn't white's missing knight (which needs 3 move to get there), that knight had to be captured in d4 by the e pawn, and that means the queen or bishop had to capture it on their way to capture on the c-file, adding another move anyway (not to mention what it means about the missing white pawn). That's another move. (9 total)

This position without possible castling requires two more moves (moving the castle or king back and forth), and it's impossible to fit them in.

# Answer
> -5 votes
Sorry, no, White -cannot- castle queenside in this position. Retrograde analysis has nothing to do with it. The official rules of Chess explicitly state that, in castling (either side), neither the king -nor the moved rook- is allowed to pass over a threatened square. The Black rook on b2 ruins it.

---
Tags: castling, retrograde-analysis
---


# Question
Title: How to play more chess without your brain tiring
It used to be a common problem for me to have very high calculating ability for the first few matches, and then I would make tons a blunders when I play the 10th or more. While for the most part memorizing lines, and having tactics become more inherent is allowing me to play more games, but I still can’t command the high level of analysis I would of at the beginning of the day.

So how do I keep from my brain exhausting?

---

“Do you drink water during that time? Do you snack or drink soda?”

For the most part, no. I’m in the zone

# Answer
Following the general rules for staying physically fit are probably a good idea. Also getting enough sleep before a match. These things always helped me. Fischer was noted for staying physically fit. Also he drank apple juice during play. Getting up and moving around also would seem desirable, since that keeps your blood pumping as well as providing a temporary distraction from your game, which should refresh your thinking. There are human limits to endurance though no matter what you do. I've noticed that as I age (I'm 80), I tend to fatigue sooner than I used too. There's probably no cure for that.
> 1 votes

# Answer
Since you answered my comment that you don't drink water, sodas or eat snacks during games, maybe you should give these a try.

Drinking water is very important since it keeps your body (and your brain) hyrdrated, keeping the electricity flowing and helping you focus.

Snacking and drinking soda can give you some carbs for bursts of energy. Several chess players eat pieces of chocolate to give them some energy.
> 0 votes

---
Tags: analysis, learning
---


title: Can one simulate a top GM strength?

text:
# Question
Title: Can one simulate a top GM strength?
I would like to know *roughly* if a top GM could win a given position against a top engine.

Is there a way of adjusting an engine's settings to simulate the strength of a top GM in order to make it play against a full specs engine? If so, which engines allow for these adjustments?

# Answer
> 2 votes
Ubisoft's *Chessmaster: Grandmaster* edition allows you to set games between artificial players. One is the engine itself and there are simulated top players, e.g. Anand. You can set the games from the starting position or from a set position.

Please see my answer to Looking for a good chess program with a couple of features for relevant screenshots.

---
Tags: engines, software
---