title: How respectable is the CM title?

text:
# Question
Title: How respectable is the CM title?
I know a man who has the CM title and his wife is WGM. They wrote a book together and on the cover her name is given with the WGM title but his name is left without his CM title. I asked him about this and he insists that he is rather embarrassed by the low title.

I am wondering if it is advisable to put his title on the book cover. Will it confer respect or rather discourage readers? The readers are supposed to be beginners or amateurs or even chess enthusiast that do not really play chess.

Any answers should focus on how the title is perceived by potential buyers of the book, and not on the technical details of obtaining the CM title.

# Answer
> 11 votes
There are, of course, some players who have been given the title in perfectly "respectable" circumstances like reaching a certain rating or reaching 50% in an Olympiad. However, try this. Go to the FIDE rating website and do an advanced search for titled players sorted by rating ascending.

The first 7 players in the list are WCM with ratings between 1032 and 1143. The next is a WFM with a rating of 1154! Which kind of throws doubt on the WFM title too. Then the first CM with a rating of 1161. Ignoring the WCMs for the moment and just looking for CMs we see that the next ones come in at 1204, 1247, 1282, 1298.

What we also see with these very low rated CMs and WCMs is that they are very young, some as young as 7 years old. And therein lies a clue. Another way to get the WCM and CM titles is by finishing in places 1 through 3 in world and continental championships in age groups going down as far as under 7.

These titles are titles for life so if they give up altogether or just play a few games a year and stop improving they will always have their titles.

You judge if giving out titles to players with sub 1200 ratings devalues those titles or not.

# Answer
> 3 votes
The CM title is awarded by "just" having a 2200+ FIDE rating, and after some tournament results. Something similar happens with FIDE Masters (needed rating is 2300+).

Such ratings correspond to a strong amateur player, but they're far away from traditional GM and IM titles, which also need three norms before being awarded.

You have more info on this topic at FIDE Title Regulations

# Answer
> 3 votes
Another way to look at this question is to ask how the players who are eligible for the title rate the title compared to other titles as reflected in the take-up rate.

Every month FIDE publish files of rating data for all current FIDE registered players which also includes details of the titles they have. From these files it is possible to extract counts of how many players in different rating ranges have which titles.

Doing this for the December data gives these results.

First the number of players with each of the different titles (I'm just looking at "open" titles rather than women only titles).

GM - 1647
IM - 3762
FM - 7869
CM - 1663

The first thing to note is that the higher the title the fewer players have the title, with the exception of CM. There are only a few more CMs than GMs.

Next, since probably a significant number of CMs got their title by a tournament performance rather than reaching 2200 ELO, try and get an estimate of how many players got the title by rating.

Since the FM title works in a similar way I will compare the two. A player can reach the required rating for a CM or FM title and get the title for life but as they get older and weaker their rating goes down. So, I'm going to look at the number of titled players above a floor 200 points below the required rating.

The number of FMs with a rating of 2100 (=2300 - 200) or over = 7244. This is less than 10% down on the total number of FMs = 7869.

The number of CMs with a rating of 2000 (=2200 - 200) or over = 957. This is more than 40% down on the total number of CMs = 1663.

Next I'm going to look at the number of players who are eligible for the CM title by rating but have no title and do the same for the FM title.

Number of players rated 2200 or over = 21047.
Number of players rated 2200 or over with no title = 9665.
So, about 45% of the players who are eligible for the CM title don't want it badly enough to apply.

Number of players rated 2300 or over = 8750
Number of players rated 2300 or over with no title = 1513
So, about 17% of the players who are eligible for the FM title don't want it badly enough to apply for it.

If you narrow down the range for the CM title to only look at 2200 to 2300 (so, eligible for the CM title only) then you get -

Number of players rated between 2200 and 2300 = 12297
Number of players rated between 2200 and 2300 with no title = 8152
So, about 66% of the players who are eligible for the CM title and not eligible for other titles are not interested.

Overall those figures tell me that players who are eligible for titles don't rate the CM title anywhere near as much as other titles.

# Answer
> 2 votes
Many informative answers have been given, but to answer the real question:

> The readers are supposed to be beginners or amateurs or even chess enthusiast that do not really play chess. The answers should focus on how the title is perceived by potential buyers of the book, and not on the technical details of obtaining the CM title.

I have been playing chess for over 20 years so in that regard, I’m not a beginner. Yet my current rating is about 1500 — though on lichess it’s about 1950.

When I buy a chess book I indeed look at whether or not the writer is an IM or GM so I know the author knows what he is talking about. Then again, they might know how to play chess, but be very bad at explaining the concepts and teaching others about the game.

A lower rated player could be better at explaining the concepts needed by lower rated players needed to improve their game. Playing chess and teaching about it are two different things.

Although I’m not easily impressed anymore and I’m hesitant to buy books from CM or FM authors, I’m still more inclined to buy books from them than from an untitled player. To me, those titles are still FAR away and getting them is still an impressive accomplishment. I would imagine it would be even more impressive to those that do not really play chess.

---
Tags: fide, books, titles
---


# Question
Title: Is a gambit still a gambit if it's calculated through to the end?
I recently gambitted a knight (I call it a gambit as I gave away a knight without being able to take back).
However I had calculated through all the possibilities and five moves or so later I have an extra pawn and a better position. Does this still count as a gambit or doesn't it as I know I can get the material back?
Essentially, what is the actual definition of a gambit?

# Answer
> 10 votes
No, it's not a gambit; a gambit is 'just' a sacrifice which is part of (well-known) opening theory, nothing more, nothing less.

But, technically, what you describe is not even a real sacrifice, but a 'sham sacrifice'.

Wikipedia gives the following definitions:

> ### Real versus sham
>
> Rudolf Spielmann proposed a division between sham and real sacrifices:
>
> * In a 'real sacrifice', the sacrificing player will often have to play on with less material than his opponent for quite some time.
> * In a 'sham sacrifice', the player offering the sacrifice will soon regain material of the same or greater value, or else force mate. A sham sacrifice of this latter type is sometimes known as a pseudo sacrifice. (Rudolf Spielman, "The Art of Sacrifice in Chess", 1995, Dover, ISBN 0-486-28449-2)
>
> In compensation for a real sacrifice, the player receives dynamic, positional, or other non-material advantages which he must capitalize on, or risk losing the game due to the material deficit. Because of the risk involved, real sacrifices are also called 'speculative sacrifices'.

If the name 'sham sacrifice' sounds too negative to you, just call it a 'tactical combination'.

---
Tags: gambits, terminology
---


# Question
Title: Why do chess tournaments award so many points for a draw?
Nobody likes a draw. Why then do chess tournaments provide incentives for players to go for a draw by awarding significant points for a draw? Typically, a win is 1 point, a draw is 0.5 points for each player, and a loss is 0 points. So a draw is **half** of a win.

This is comparatively to other sports quite a large amount of points to get for a draw and essentially ends up encouraging players to play for a draw more often. Imagine you are rated 2500 and you are going up against a monster like Carlsen. Who in their right mind wouldn't want to just go for a draw and get a whole 0.5 points from that?

In comparison, take other sports, like football, where a draw is **1 point** and a win is **3 points**. So the point system encourages one to go for a win. Similarly, many other sports simply don't **allow** draws and if a game ends in a draw, some sort of extra-time is played so that a winner is found (in Chess, I guess this could be arranged by having a quick blitz match best of 3 after a drawn game to decide a winner).

So why do chess tournaments give so many points for a draw? Wouldn't it be better to follow a different point system, like 3/1/0 as in football, to encourage players to go for a win?

# Answer
> 0 votes
1. I don't see how tournaments incentivize people to go for a draw. You literally cannot win any tournaments by drawing every game.
2. Yes sometimes there are draws that are clearly prearranged but other than that only bad players say draws are bad for chess. The funny thing is that these low rated players are usually not getting draws even against similar strength opposition. They also can't figure out what's going on in high rated games without an engine.
3. The issue being your football system is it would change the elo system and encourage win trading. The best way to gain elo would be win farming against much weaker opponents, as you would lose elo drawing against people of similar elo. The players with the highest elo would not be participating in these super tournaments to maintain their elo. Also colluding draws is nowhere near as damaging as win trading in this system, as the tournament winner cannot really win by drawing every game, but can easily win winning 50% and losing 50% of his games. Also it is freelo due to 1 win and 1 loss against a similar rated opponent being a net gain in elo.

---
Tags: tournament
---


title: Is this a smart draw offer?

text:
# Question
Title: Is this a smart draw offer?
```
[Event "Live Chess"]
[Site "Chess.com"]
[Date "2018.12.27"]
[White "SergioRamos2"]
[Black "SmojLee"]
[Result "1/2-1/2"]
[ECO "B57"]
[WhiteElo "1640"]
[BlackElo "2175"]
[TimeControl "600"]
[EndTime "10:48:30 PST"]
[Termination "Game drawn by agreement"]
[CurrentPosition "8/3kb1p1/7p/6p1/8/3K4/6PP/4R3 b - - 1 54"]
[FEN ""]

1.e4 c5 2.Nf3 d6 3.Nc3 Bd7 4.Bc4 Nc6 5.O-O Nf6 6.d4 cxd4 7.Nxd4 a6 8.f4 Qb6 9.Be3 Ng4 10.Nd5 Nxe3 11.Nxe3 Nxd4 12.Kh1 Nc6 13.Qe2 e6 14.Rab1 Be7 15.c3 Qc7 16.a4 O-O 17.Bd3 Rfd8 18.Rf3 Rac8 19.Rh3 h6 20.Rf1 Bf8 21.Rg3 Ne7 22.Qh5 Ng6 23.f5 exf5 24.exf5 Qc5 25.b4 Qe5 26.Ng4 Qd5 27.c4 Rxc4 28.Bxc4 Qxc4 29.Rd1 Qe4 30.fxg6 fxg6 31.Qd5+ Qxd5 32.Rxd5 Bxa4 33.Kg1 Bc6 34.Rd4 d5 35.Ne5 Bd6 36.Nxc6 bxc6 37.Ra3 c5 38.Rd1 c4 39.Kf1 Bxb4 40.Rxa6 Kf7 41.Ra4 Be7 42.Ra5 Ke6 43.Re1+ Kf6 44.Rd1 Rc8 45.Raxd5 c3 46.Ra5 g5 47.Ke2 Kf7 48.Ra7 Ke6 49.Kd3 Kf7 50.Rf1+ Ke8 51.Re1 Rd8+ 52.Kxc3 Rd7 53.Rxd7 Kxd7 54.Kd3  1/2-1/2

```

This is a game I had with black and I was doing well with time and position but it came down to one move that made me lose! Luckily my opponent is time trouble so he had to offer a draw. Was it smart of me to accept it since he was up by +1 and he only had 40 seconds left? I would appreciate if someone could analyse the game to see what went wrong, thank you!

# Answer
> 4 votes
My first thought was that black had won a piece by move 12, and should have been able to win without getting into such heavy complications. For instance, a move like 15...Qc7? is just a bad move from a strategic standpoint. It's not necessarily losing or anything, but black doesn't know for sure where the queen is supposed to go, whereas black knows for sure that the king should get to safety. This is a good rule of thumb: begin by dealing with the pieces you know where they are going before manoeuvring with the pieces for which it's unclear where they stand better.

Basically what went wrong for black in this game is not a one-move mistake in my opinion. Black went on with a standard plan in the open sicilian, ignoring the fact that white was preparing a kingside attack. This made everything very awkward in the end, and once white's attack was actually picking up steam it was already unneccessarily difficult for black to respond properly. I'm sure that one could make detailed remarks on many of the moves played in this game, but noting that this was a 10-minute blitz game I see little reason to make a detailed analysis of this game. One suggestion I would make for black in this game is that black should've played 11...Qxd4 instead of 11...Nxd4. The reason is that black is already a full piece up at this point, and if the queens are traded white is just doomed, since there will be no talk about kingside counterplay then.

As for the question about the draw offer, black has zero winning chances in the final position. In general, it's never a bad idea to accept a draw offer in a worse position even if your opponent is low on time, and this is no exception to that rule. 40 seconds is enough for white not to blunder a rook, and realistically black is the only one actually risking anything by playing on. But in the end I think the position is drawn and I see no good try for white to actually make any progress.

# Answer
> 4 votes
> Was it smart of me to accept it since he was up by +1 and he only had 40 seconds left

The final position was a **dead draw**, so there was nothing wrong taking the draw offer. However, you would probably win the game by time if you had continue (assuming you had more than 40 seconds on the clock and no increment). Moved your king aimlessly, and pushed for h5-h4 to reset 50-move counter. It would have been a battle on mouse reaction, not chess anymore.

It was a wise decision by position, but unwise if you really wanted a win at all costs.

---
Tags: analysis, sicilian-defense, blunder, time-management, online-blitz
---


# Question
Title: Amount of search per decision: GMs versus AlphaZero and Stockfish
In Demis Hassabis' presentation at the the Kinds of Intelligence Symposium in January 2018, grandmasters are compared to AlphaZero and Stockfish along an interesting metric: how many moves are searched per decision made? It is claimed that \`\`human grandmasters'' considers 10 of moves per decision they make, AlphaZero tens of thousands, and Stockfish tens of millions. Is there any scientific evidence regarding the number of moves per grandmaster or human in general? 10 seems to me a very arbitrary number. Where does it come from?

PS. I didn't know that grandmasters can be non-humans as well!

**Edit**. I missed this answer but my question is not about what make a grandmaster special? Or how many moves can foresee a grandmaster? I understand that any number would depend on the position. My question is I guess more precise: is there any **scientific evidence**, experiment, or study that tried to measure the average number of moves a human can consider during a certain amount of time?

My attempt was to read Alexander Kotov's book "Think like a grandmaster". Kotov asks this simple question: How many candidate moves a grandmaster examine? Kotov does not give any precise answer: \`\`they are unusual cases where there can be five or six, where in the next they are actually seven'' but his book dates back from the seventies (1971 for the English translation) and I was wondering if someone tried to test this more scientifically, by estimating an average number.

# Answer
I assume you're wondering about the speed of calculating moves. I'm not sure how you would go about figuring out the max #moves a GM can calculate (I guess the experiment runs until they fall asleep?).

I'm an FM and I can calculate a couple of moves per second (1-3), assuming the calculation is trivial enough. For more complicated positions where I need to analyze in the middle of my calculations, the speed significantly slows down to how long I need to analyze. This depends entirely on the complexity of the position. GMs are probably slightly faster than me on average. I'm not sure where the "10 moves per decision" figure came from.

From what I understand of AlphaZero, it uses a very strong intuitive (generated from playing itself thousands of times) combined with Monte Carlo Tree Search. This search plays out random simulations of games, starting from where AlphaZero is calculating, and then the move that ends up scoring the highest is chosen.

Stockfish uses the typical minimax with alpha-beta search algorithm, combined with other algorithms which increase efficiency (esp. iterative deepening). It doesn't calculate to the end of the game in each branch, but instead goes up to a certain point and evaluates the resulting position based off its evaluation heuristics.

As for the speed of moves/second between AlphaZero and Stockfish, it comes down to how fast (on average) they can evaluate one position/node. The overall way they traverse the calculation tree is irrelevant when talking about raw calculation speed. Calculation speed comes down to two things:

* The speed of the computer the Engine is running on.
* The algorithm used to evaluate a position.

Assuming Stock and AlphaZero are given equal computers, then on average I would assume AlphaZero is faster (I don't have any official sources for this though). This is because it evaluates based off a very fined tuned intuition which it learned by playing itself over and over. Meanwhile, Stockfish uses evaluation heuristics thought up by humans. They're very good heuristics, but still only human made.

On ChessBase, Stockfish evaluates over 1 million nodes/positions per second. I don't know what AlphaZero's speed is, but when they eventually publish the engine you could check it out then.
> 1 votes

---
Tags: grandmaster, alphazero, candidate-move
---


# Question
Title: Is it true that Chess is generally more played by men?
I have recently heard that the only 5% percent out of entire chess players are women. I find this suspicious. Who says that only men can play chess? Is this statistic true, and if it is, why?

# Answer
> 8 votes
I don't know that it's 95%, but it's close.

Why aren't there more female players? Probably a combination of things certainly including cultural gender bias. Women can surely play the game but American culture doesn't seem to reward them for it.

In about 1990, my B-player rating would have put me in the top 50 women players in the country. A little later, the US got a lot of immigration from ex-Soviet Bloc countries. This included a very good number of strong female players. I can only surmise that their cultures were more supportive of the women.

Further, I feel the game was invented as a war game by men for men and as such probably has a certain character that is best appreciated by men.

Compare to Go, a game of remarkable complexity, which has a *much* higher level of female participation.

# Answer
> 8 votes
Among active players in the United States, about 15% seem to be women.

If you look at the rankings on this page, there are currently 9513 women active out of 64634 total players. That's 14.7%.

My guess is that the composition of female players skews more heavily towards juniors than the composition of male players, but I didn't find any numbers on that. I say this because I saw more female players at scholastic tournaments as a child than I do now at open tournaments as an adult.

# Answer
> 7 votes
> I have recently heard that the only 5% percent out of entire chess players are women.

In 2018 this is certainly false. The statistics from the November 2018 FIDE rating list are that there are 668785 active players of whom 99325 are female. That is a female participation rate of about 15%.

**Update January 2020**: *The statistics from the January 2020 FIDE rating list are that there are 771484 active players of whom 120065 are female. That is a female participation rate of about 15.6%.*

The statistics from the May 2012 FIDE list (when you wrote this question) are that were 87538 active players of whom 7226 were female. That is a female participation rate of 8.25%. So even when you wrote this question your number was inaccurate.

The big difference between May 2012 and today in FIDE rating terms is that the current figures also include rapid and blitz and also FIDE's online Arena for online chess. FIDE rating of rapid and blitz only started with the July 2012 list and has grown massively since then. I believe the FIDE online Arena only started in late 2015.

One other factor also affects the figures and that is that the FIDE default when a new player is recorded is male. If the registering federation does not specify sex then the player is registered as male. This obviously introduces distortions in the figures. It should be noted that FIDE has made great efforts in more recent times to clean up its data and correct errors. More recent FIDE data is more accurate than older data.

Now I don't know which federation you come from so your figure could be accurate for your federation even though it is inaccurate overall.

Figures vary wildly by federation and not necessarily in the way that you might imagine (unless you listen to Jordan Peterson).

Looking at the female participation rate (100 x active female players / active players for federations with 100 or more active players) gives these 10 federations as bottom of the list from the May 2012 list -

Czech Republic - 4%
Spain - 3.9%
Sweden - 3.8%
Nepal - 3.4%
Italy - 3.3%
Finland - 2.6%
Belgium - 2.5%
Switzerland - 2.3%
Ireland - 2.1%
Denmark - 1.5%

And here are the top 5 from the May 2012 list -

Vietnam - 39.1%
Georgia - 33.7%
China - 31.2%
Ecuador - 23.8%
Azerbaijan - 23.6%

Here are the corresponding figures from the November 2018 list (restricted to federations with 1000 or more active players - about 10x as many active players so increase the "noise" filter by 10x).
First the bottom 10 -

Sweden - 6.3%
Israel - 6.3%
Switzerland - 5.9%
Argentina - 5.3%
Netherlands - 4.8%
Norway - 4.8%
Finland - 4.4%
Ireland - 4.2%
Denmark - 2.7%
Libya - 0.9%

And the top 5 -

Mongolia - 41.9%
United Arab Emirates - 35.6%
Sri Lanka - 34.0%
Vietnam - 32.5%
Malaysia - 28.3%

> Who says that only men can play chess?

Nobody says that and the statistics certainly don't say that either. What they do suggest is that men *want* to play chess much more than women. Where women have a greater choice of what sort of things they can do, as in the Scandinavian countries, it appears that many more of them have better things to do with their time than play chess ;-).

PS It's a shame there isn't an international knitting federation publishing data we could use to extract male participation rates in knitting.

NB For anybody interested in the raw data, FIDE publish rating file data going back to 2001. For data before 2001 there is the Olimpbase site, but their data is very "dirty" and will need a lot of work to eliminate/merge duplicates and correct obviously false data before it can be used.

# Answer
> 6 votes
Chess tends to impersonate **war**.
No one says women can't fight, but it's usually considered (culturally) as more of a men's activity, don't you think ?

I'm very curious about the “why” aspect myself, but that probably calls for much socio-psychology I'm not near knowledgeable enough at, and probably isn't even well known yet, not to mention far from the scope of this site.

For real statistics, I guess scripting over a FIDE ratings database wouldn't be too hard, probably even mentioned in the introductory section of *Women in Chess*.
Most people (and other answers) cite a 5-15% figure.

# Answer
> 3 votes
Despite all feminist claims, it's not cultural, but biological. In countries where supposedly the culture is more supportive for equality in activities (like USSR), males are by far relatively predominant in chess, the same as in US. It's the same with careers. It hasn't made much of a difference now that engineering, for instance, has been a field accessible to women for a long time. Most of them simply prefer social activities more. As Desmond Morris says, the brains of men and women work differently from each other. This doesn't imply any inferiority, simply there are activities more suited for men and activities more suited for women. E.g. dyslexia is almost wholly an issue for men, not for women.

---
Tags: statistics
---


title: Bronstein vs Winter

text:
# Question
Title: Bronstein vs Winter
In this game, http://www.chessgames.com/perl/chessgame?gid=1365631

The engine says that 20. Na5 is a blunder. However, I fail to understand why it is. Also, I am surprised at White's choice of moves here with c4 instead of Qxd6. Essentially he is giving a Bishop for free.

```
 [title "Bronstein vs Winter"]
 [fen "r2r2k1/pp3p1p/1n1B2p1/3P4/2q5/1N3P2/PbPQ1RPP/3R2K1 w - - 1 20"]

 1. Na5 Qa6 2. Qb4 Rxd6 3. c4?

```

What is the problem with 22. Qxd6 Qxa5 line where White gets a Rook and a pawn for his Knight and Bishop, the position looks equal. The engine says it is -3 for Black and gives a long long line but I am unable to see how it gives Black an advantage.

# Answer
In the starting position, White should immediately protect his Bishop with 1.Qb4. Then, after 1...Qxb4 2.Bxb4 Rxd5, the endgame is close to equal.

Instead, after 1.Na5 Qa6, White's bishop is still under attack and his knight is vulnerable. The game continued 2.Qb4 Rxd6, and now if White plays 3.Qxd6, Black has 3...Qxa5. Black has won two pieces for a Rook since White's queen got overloaded.

You're right though that 3.Qxd6 was a better move than 3.c4, but only by about 0.40 according to Fritz. Both moves are under -2. The point behind 3.c4 is that White's f2-rook is attacking Black's b2-bishop and threatening to take it. The bishop wasn't already threatened by White's queen since after Qxb2 Black has ...Qxa5.
> 4 votes

---
Tags: analysis
---


# Question
Title: Why do chess tournaments allow absolutely scandalous draws?
I am currently watching the Rapid World Championship and the amount of draws between players is absolutely shocking. I'm not talking about games where each player fights to the end and the game just happens to be a draw - that is perfectly okay in my opinion.

But so many games are being drawn on default - players are simply agreeing to draw far before any sort of endgame is reached. Just now, 5 minutes ago, Anish Giri drew a game after **10 moves**. 10!!! TEEEEN!!!

Why do chess tournaments allow this scandalous behavior?

Imagine if any other sport was played this way. Imagine if Barcelona and Real Madrid are playing football, and they just decide to leave the pitch after 20 minutes because they no longer want to play, and agree to a draw.

Why is this behavior not banned? Why isn't a rule enforced so that a draw can only be reached after many moves (as was the case in the World Championship with Caruana and Carlsen)?

# Answer
Anish Giri was likely playing a "solved" opening, one in which all lines have been analyzed to a draw. Also, Giri is **extremely** hard to beat and draws many of his games (his weakness is that he doesn't often win). In this situation, there was likely no room for progress outside of severe blunders, so it's almost a respect issue, where Giri and his opponent respected each other enough to admit that no blunders were likely to be made, especially in this line. This sort of "guaranteed ending" does not occur in games like football or baseball or whatever.
> 1 votes

# Answer
Many FIDE tournaments do have a rule where a draw can only be reached after \>= 30 moves. If I recall correctly, this rule is quite predominant especially in the closed tournaments which super GMs play in.

I suppose they could also implement the rule in rapid and blitz tournaments, but these events are more informal and less important. The need for so many extra strict rules decreases.

Sports like hockey, football, etc don't allow quick draws since the game could never naturally end early on in a draw. In chess though, the game could easily end (naturally) in a draw.
> 0 votes

---
Tags: draw
---


# Question
Title: A confusing situation-is this stalemate?
Today I played a game, and it was my turn in the endgame.

I had only one pawn, which is blocked, and my king left. But my king could move only to a single square legally, as it would otherwise be in check. However, on the next move of mine, I had to put my king back on the square that it came from. I had to repeat these moves 8 or 9 times, with no another moves available. My king was stuck within those 2 squares.

I was confused, and I still am. Eventually, my opponent promoted a pawn to a queen, and afterward, in 2-3 moves, he checkmated me.

Can anyone explain this type of situation? Is it stalemate, or something else?

# Answer
> 2 votes
A stalemate is when, during your turn, you cannot make any legal move. The game then stops as a draw.

As long as you can make a legal move, with any piece, it's not a stalemate. Therefore the situation that you have described is not stalemate, as you had legal moves every single turn.

There isn’t really a name for the situation that you are in, but it is best called a repetition for simplicity’s sake.

Now, if your opponent also made the same moves as well every single time, and it were a tournament it would be called a threefold repetition and you could claim a draw. But only you are repeating your moves.

---
Tags: stalemate
---


title: What is the fastest possible checkmate?

text:
# Question
Title: What is the fastest possible checkmate?
What is the fastest/shortest possible checkmate? What is the minimum amount of moves to checkmate a side?

# Answer
Two moves! And this has a name as well! It is called Fool's mate!

```
 [title "Fastest Mate"]
 [fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

 1. f3? e5 2. g4?? Qh4++

```
> 5 votes

---
Tags: checkmate
---


title: Do engines remember previous analysis?

text:
# Question
Title: Do engines remember previous analysis?
Suppose I let the engine analyze a given position (let's say for simplicity the starting position), and then I execute the move suggested by the engine (let's say 1. e4). Then I let the engine analyze the upcoming position (black to move after 1. e4), and after a while I take the move back and let the engine again analyze the original position (the starting position, white to move again), will it:

1. utilize the analysis done on this position last time and look wider at each PLY?
2. utilize the analysis done on the upcoming position (after I played 1. e4) and possibly reevaluate 1. e4 based on that?

# Answer
Yes. This is what hash is: it stores previous analysis.

> Hash is a database that stores information about positions previously searched, how deeply they were searched, and what was concluded about them. See also https://www.chessprogramming.org/Hash\_Table
> 4 votes

# Answer
I can't speak for all game playing engines, but a good engine would indeed remember past analysis. Having a "first-draft" evaluation of a position (and all the positions that can arise from each move) allows the engine to do move-ordering. This is where it looks at all possible moves in the order of "probable best" to "probable worst", based off the aforementioned "first-draft" evaluations that it saves.

By looking at the subtrees of moves that are probably better first, the engine is able to perform the minimax + alpha-beta algorithms MUCH more efficiently. Already looking at a good move/subtree allows you to prune a bad move/subtree, but not vice versa.

High quality engines actually perform their search via iterative-deepening. Search one move ahead, then go back to the starting position. Search two moves ahead, then go back to the starting position. All the way up to N moves ahead. That might seem inefficient, but it shows how powerful having some preliminary knowledge of a position and its moves can be before expanding further on it.

For your specific question, I assume you mean when you go forward and backwards *manually* in ChessBase. In this case I'm not sure if the engine remembers everything it calculates, because that's a lot of data to store just for the specific case of the user clicking back to a previous position. It seems pretty space inefficient. I tested it on ChessBase by making a move and seeing how fast the engine's depth climbed. Getting to depth 20 was slightly faster on the second time than the first time, but it wasn't instantaneous on the second time (which it should be if it did remember all its calculations the first time I manually brought it to the position).
> 3 votes

---
Tags: engines
---


# Question
Title: Which is better in the Rossolimo Sicilian, 3... e6 or 3... g6?
```
[FEN ""]
[StartPly "5"]

1.e4 c5 2.Nf3 Nc6 3.Bb5

```

In this opening is it better to do e6 to activate the dark square bishop which will protect c5 pawn. If the opponent plays Bxc6, it will have a double pawn in the c file but the dark squared bishop might help the pawn on c5 or g6 because I think the Bishop will be much better on the long diagonal. Also keeping open the option to recapture on c6 with the d-pawn to open the Queen and light squared Bishop. Also not worried about them doubling the pawns because of the Bishop pair to compensate.

I gave my explanation for both moves but which move do you think is Better?

# Answer
It's really a matter of taste and style. One option may suit more your style than the other. But if you believe in a "moneyball approach", 3...e6 appears to be the "best" move for black based on a search on the 365chess.com website.  Regarding the number of games, I guess that the difference in black's winning chances (30.2% for 3...e6) versus (26% for 3...g6) should be statistically significant.

When you control for the level of players by focusing on the Master Database, the statistics also appear to favor 3...e6 over 3...g6.
> 7 votes

---
Tags: opening, analysis, learning, sicilian-defense
---


title: Human and computer vs computer alone

text:
# Question
Title: Human and computer vs computer alone
How much stronger are human/computer teams vs. computers alone? My understanding is that that advantage is enough to be decisive, especially in correspondence play, but just how large is it?

# Answer
Well, humans have the advantage of identifying potential long term positional ideas where as computers are better at calculating quite complex positions. I predict most of the games would end up in draws but in some situations (specially endgames where you need depth as well as complex strategic plannings), human and computer partnership would triumph. A famous example would be the Caruana vs Nakamura game where computers never identified the queen sacrifice. https://www.youtube.com/watch?v=dMjj9SPnlBE.

Also it's self evident that artificial intelligence programs such as Alpha-go-zero has both human like abilities (long term strategic plannings) as well as computer like abilities (deep calculations). So it would be a great example for you to see the games played between Alpha go zero and chess programs like Stockfish (https://www.youtube.com/watch?v=vP2J4WNN4Qg)
> 2 votes

# Answer
It pretty mcuh depends who the human is. Me + SF can almost always beat SF alone with longer thinking time. It does not take much insight to do that, as I know by heart precisely what moves in precisely what lines SF misplays and precisely what pawn structures it plays badly. Every second move or so, SF will make a mistake, of which the human might take advantage. 3 such mistakes/inaccuracies are sufficient to lose you the game. On the other hand, I will not blunder anywhere in the game as I could have if playing alone, as SF will assist me in tactics, so me + engine could theoretically win every single game. Of course, this will not happen, but this is just the theoretical side of it. If the human player does not know the engine's weaknesses, then there is not much added value to the team. For example, me + unknown engine versus unknown engine might end unexpectedly, even with a win for the unknown engine. In this case, the human might even be a burden, if he chooses not to follow the engine's recommendations. In general, however, a team should always be not only stronger, but significantly stronger, it is always like that when the fight is 2 on 1 and the single entity is of comparable strength.
> 0 votes

---
Tags: computer-chess
---


# Question
Title: Questions about the beginning of this game
```
[Event "Live Chess"]
[Site "Chess.com"]
[Date "2018.12.29"]
[White "Leon_Likes_Chess"]
[Black "SmojLee"]
[Result "0-1"]
[ECO "B47"]
[WhiteElo "1625"]
[BlackElo "2310"]
[TimeControl "600"]
[EndTime "14:52:01 PST"]
[Termination "SmojLee won by resignation"]
[FEN ""]

1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 e6 5.Nc3 Qc7 6.Ndb5 Qe5 7.f4 Qb8 8.e5 a6 9.Nd6+ Bxd6 10.exd6 Nh6 11.Be2 Nf5 12.Ne4 b5 13.g4 Nh4 14.Rg1 Qb6 15.Nf2 Nd4 16.Be3 Ndf3+ 17.Bxf3 Qxe3+ 18.Be2 Nf3+ 19.Kf1 Nxh2+ 20.Kg2 Bb7+ 21.Kxh2 h5 22.gxh5 Qxf4+ 23.Rg3 Qxf2+ 24.Kh3 Qf5+ 25.Kh2 Rc8 26.Bg4 Rxc2+ 27.Be2 Qxh5+ 28.Kg1 Bf3 29.Qxc2 Qh2+ 30.Kf1 Bxe2+ 31.Qxe2 Qxg3 32.Qf2 Rh1+ 33.Ke2 Qxf2+ 34.Kxf2 Rxa1  0-1

```

This is a 20min rapid game I played with black and I have questions about the beginning of the game:

Question 1 - What was the purpose of 6.....Qe5, it looks like it loses a tempo and gives White an advantage

Question 2 - Doesn't 13.g4 weaken the White king?

Question 3 - Why 14. Rg1? White should really try to get his King to safety and focus on development

I would appreciate if someone can give me their thoughts about the rest of the game, thank you!

# Answer
> 2 votes
> What was the purpose of 6... Qe5? It looks like it loses a tempo and gives White an advantage.

I think you are asking the wrong person. You said you were playing black, so, why did you play this move? Exactly as you say, it loses a tempo and worsens your position. 6... Qb8 was much safer.

> Doesn't 13. g4 weaken the White king?

I don't think so. White has a nice setup after 13... Nh4 14. Qd3, and even has the initiative as a kingside attack is ready to be launched against the black king. However, accurate play is required:

```
[FEN "rqb1k2r/3p1ppp/p1nPp3/1p3n2/4NP2/8/PPP1B1PP/R1BQK2R w KQkq b6 0 1"]

1. g4 Nh4 2. Qd3 f5 3. gxf5 Nxf5 4. Bh5+ g6 5. Bg4 O-O

```

The bishop defends f4, so white has nothing to worry about.

> Why 14. Rg1? White should really try to get his King to safety and focus on development.

I wouldn't say Rg1 is a blunder, though, as you said, development takes precedence here. The queen must take part in the kingside action via Qd3. You can also get your king to safety - the engines agree, but it is not a humane decision to get your king walking:

```
[FEN "rqb1k2r/3p1ppp/p1nPp3/1p6/4NPPn/8/PPP1B2P/R1BQK2R w KQkq - 1 1"]

1. Kf2 (1. Kd2? Bb7 2. Qe1 Ng6 3. Kd1 Nd4 4. Bd3 O-O {and the white king ends up exposed in the middle of the board.}) f5 2. Kg3 fxe4 3. Kxh4

```

Your play was almost perfect throughout the middle game, though you missed a mate-in-4 starting at move 28 (the position was winning for black anyways):

```
[FEN "4k2r/1b1p1pp1/p2Pp3/1p5q/8/6R1/PPr1B3/R2Q2K1 b k - 1 1"]

1... Qc5+ 2. Qd4 Qxd4+ 3. Kf1 Rh1+ 4. Rg1 Rxg1#

```

---
Tags: opening, analysis, learning, sicilian-defense
---


title: Draw offer without executing move

text:
# Question
Title: Draw offer without executing move
Scenario: It's Player A's move, and without executing a move he offers a draw. Player B replies "Please make a move". Player A then makes a move, where upon player B says: "Ok, I accept". Is it now possible for Player A to say that the draw offer no longer stands, and was in fact nullified when it was not originally accepted during the period between the offer and the move that Player A did?

# Answer
No, Player A cannot do this. FIDE rules of chess article 9.1.1:

> A player wishing to offer a draw shall do so after having made a move on the chessboard and before stopping his clock and starting the opponent’s clock. **An offer at any other time during play is still valid** but Article 12.6 must be considered. No conditions can be attached to the offer. In both cases **the offer cannot be withdrawn and remains valid until the opponent accepts it, rejects it orally, rejects it by touching a piece with the intention of moving or capturing it, or the game is concluded in some other way**.

Key parts highlighted. Player A made the draw offer at one of these "other times", so it's still valid and cannot be withdrawn. Player B asking player A to make a move, and player A actually making a move, are not one of the four actions that can terminate the draw offer, so the offer remains valid.
> 10 votes

---
Tags: rules, draw
---


title: Teaching endgame ideas to children

text:
# Question
Title: Teaching endgame ideas to children
I am looking for some advice and pointers on teaching young kids about endgame ideas. (Say for children ~8 years old). I am asking specifically regarding my nephew, but I have seen this happen to other kids as well. Often, they know how to mate with K+R vs K, K+Q vs K and similar.

In their actual games, they will get a good position (often even a piece advantage) and then they are just meandering instead of casting a mating net. Here's the interesting thing, if my nephew is shown a mate in 2 or 3, he'll usually figure it out. But in his own games, he seems happy to just keep making the moves.

Any suggestions and link/book pointers from parents, coaches welcome.

# Answer
One great resource for teaching kids chess is www.chesskid.com. In particular, if you want to learn more about teaching the endgame to children, you can checkout chesskid.com's articles on endgames. A simple google search will yield you a ton more results, but this should get you started.

In my opinion, the reason why kids and adults in general solve tactical problems in isolation, but fail the same tactical problem in an actual game is for a variety of reasons, some of which may include and in no particular order:

* Nerves - Solving an endgame puzzle with no time to worry about or no opponent staring you down is a lot easier. It is the only goal. He is not looking to beat someone.
* The goal is to solve the problem in an isolated endgame puzzle, but in an actual game, the goal is to win, therefore, he might get lost in the position and forget about the endgame pattern.
* Learning to recognize endgame patterns in an actual game is also key to learning how to solve it during a game instead of with just a few pieces on the board.

One idea is after he has played a game, if he missed anything or even if he did not, go over the endgame with him and see if he recognizes it.
> 4 votes

# Answer
It looks like he didn't quite integrate that the point of making moves is to win the game in the end.

A piece advantage is just a means of capturing more of an advantage (often, a queen *via* promotion), to easily crush defenses and mate. At least, that's what I'd go for with a piece advantage. If they don't have a piece advantage yet, then try and get it¹. I wouldn't call that endgame², though.

Now, being 8 years old, I think that this will just come as he grows and thinks more in terms of goals in a fight, and less as a game where you play moves according to some rules. **I don't think you should worry about that if he's happy as it is**. At least, not until he starts being bugged by “and now what” himself.

---

This question might be of interest.

¹ I wouldn't mind making capturing pieces the first objective of a young player once he knows checkmate is how a game ends. If he loses games while being ahead in material, he'll learn the difference.
² Endgame, in my mind, is about more equal positions, how to win and not draw, or how to get an endgame advantage. I'd call finishing a game with a piece advantage “finishing the work”, rather.
> 5 votes

# Answer
Aron Nimzowitsch covered this in his classic (well, all his books are classic) autobiography "How I Became a Grandmaster at Chess".
> 0 votes

---
Tags: learning, endgame, scholastic-chess
---


# Question
Title: Magnus vs Tomashevsky Blitz 2012 - why doesn't he take the knight on e7
I'm not sure if anyone is familiar with this game, I watched it a while ago and had just rewatched it now and cannot understand why Magnus didn't take the knight on e7.

Here's the screenshot before this went down:

The moves are in this order: Green, Blue, Red. So the board looks like this:

He doesn't take the knight, why? Instead he plays Bxb2.

I'm sorry if this is obvious to more experienced players, I'm not expert by any means just trying to get someones opinion. Thanks.

# Answer
> 3 votes
Magnus doesn't take the knight because it simply results in a loss of material:

```
[FEN "r1bqk3/p2pNpbn/1p4p1/8/2P5/1N4P1/PP2PP2/R2QK2B b Qq - 0 1"]

1... Qxe7 2. Bxa8 Bxb2 3. Rb1 Bc3+ 4. Kf1

```

By taking on b2, Black threatens to take his opponent's rook, while at the same time frees the c3 square for a check, which gains a tempo. White will then either exchange rooks or move their rook away from danger, also giving Black a chance to flee with their rook.

Taking on b2 is not the best according to engines, but at least it avoids the material loss. The position is significantly better for white.

---
Tags: carlsen
---


# Question
Title: Why in Four Knights, Italian variation the winning percentage favours black after the move 4...Bc5?
I was searching C46 Four knights, Italian variation at 365chess.com and here is what I found:

I am curious why 4...Bc5 gives black a slightly higher winning percentage. It seems to me that after 4...Bc5 it is white's turn to move and white should not have any disadvantage here.

# Answer
> 1 votes
As fuxia noted, winning percentages depend on how strong the players are, not just the opening.

Think about someone likely to play the four knights as White. Since the opening is rather unambitious and fairly easy to learn, there's a good chance this player isn't very strong. I'm not trying to generalize all players here, I'm just talking about averages. Meanwhile, Black is just following the main line moves for 1...e5. This gives no indication of Black being a weaker player.

As an aside though, the 365chess database isn't the most accurate. There are way more than 3723 games played in 4...Bc5. A look at the MEGA database or TWIC would give you more reasonable stats.

---
Tags: opening, advantage, four-knights
---


title: Why 7. Bd3 in the 3 knights opening?

text:
# Question
Title: Why 7. Bd3 in the 3 knights opening?
In this line of the 3 knights opening

```
[fen "start"]

1. e4 e5 Nf3 Nc6 Nc3 Bc5 Nxe5 Nxe5 d4 Bd6 dxe5 Bxe5

```

the best continuation according both to my engines and to databases is `7. Bd3`. Why? For instance, can anyone explain why that's better than `7. Be2` or `7. Bc4`?

Below some of the reasons I found by myself, but I would love to have confirmation or hear more:

* If the pawn on e4 moves, the bishop would attack the h7 square which might be helpful for a mating attack in case black castles king-side. `7. Be2` doesn't attack any important square
* `7. Bc4` would attack f7, but the bishop is undefended on c4 and might become a target
* `7. Bd3` gives extra protection to the e4 pawn (useful in case white needs to move the knight on c3), neither `7. Bc4` nor `7. Be2` does that

# Answer
A light-squared bishop move here is in order so that white can castle soon. The choices that you mentioned are definitely the only ones that aren't dumb/lose a tempo.

Be2 is probably the worst of the reasonable choices. Its only result is to allow castling, and it kind of clogs up white's middle - potential moves like Ne2 or Qe2, which may show up at some point, are off the plate.

Bc4 and Bd3 are both solid, I think. There likely wasn't much of a difference in the engine evaluation for these moves, and depending on the tools you used to conduct this analysis, the difference may be within the margin of error for the program. Essentially, **I'm not sure there is a measurable difference between these moves in terms of evaluation**.

**Assuming that there is an actual difference**, you might also consider that engines are fairly notorious for **NOT** playing attacking chess. It has been argued that they focus too much on material imbalances and not enough on position/pressure/psychology. The move Bc4 "feels" scary, but the engine sees that with perfect play, it isn't much of a threat. The pressure on the e4 pawn, however, will be real with perfect play, and it moves to defend that pawn.

Essentially, Bc4 *might* be more practical in a game between imperfect people, but the attack it provides is not real enough to matter in a perfect game - thus Bd3 is technicallybetter.

Play whatever you're more comfortable with.
> 4 votes

# Answer
Just to answer directly and concisely to the question:

> 7. Bd3. Why?

Well there are 2 reasons for that and one of them you already mentioned:

* Protecting the e4 pawn

This is a bit more real than it seems because the most natural moves for black are Nf6 and castles, which immediately threaten the e4 pawn by removing the defender with Bxc3. Bd3 defends it in advance, which is prophylaxis. I personally feel this is the main reason for Bd3 over Bc4.
* Kingside attack

In the future, if black castles kingside which is the most natural thing to do, Bd3 aims for h7, becoming an attacking piece, after the pawn moves of course. But the interesting part is that black will have a hard time stopping the advance because at any point white can play f4 to kick any blockading piece.

Bc4 also targets black in a kingside castled position which is why it is a reasonable move as well, but h7 looks more threatening and harder to defend for black than f7.
> 2 votes

---
Tags: opening
---


title: How many two move checkmates exist?

text:
# Question
Title: How many two move checkmates exist?
I am well aware that Fool's Mate exists. But how many two move checkmates exist in total?

# Answer
> 4 votes
8 different ways. 2 different ways for f3/f4. 2 different ways for e6/e5. 2 different ways for changing the move order between g4 and f3/f4.

# Answer
> 5 votes
I agree with the previously-given answer from Matthew Liu (please give it the checkmark), but I’ll add the standard notation of the solutions since you ask:

1.f3 e5 2.g4 Qh4#

1.f3 e6 2.g4 Qh4#

1.f4 e5 2.g4 Qh4#

1.f4 e6 2.g4 Qh4#

1.g4 e5 2.f3 Qh4#

1.g4 e6 2.f3 Qh4#

1.g4 e5 2.f4 Qh4#

1.g4 e6 2.f4 Qh4#

---
Tags: checkmate, mathematics, fools-mate
---


# Question
Title: Importing and analysing games played on chess.com
How to import entire game from chess.com game to stockfish?

# Answer
> 1 votes
I think chess.com has in-built Stockfish engine analysis, so I don't understand why you'd want to do that.

Don't like chess.com? lichess is easy. Just grab PGN of your game, import it into lichess. Select engine analysis.

---
Tags: stockfish, online-chess
---


# Question
Title: Why is this King and Pawn ending lost for White?
```
[FEN "8/8/8/3pk3/1K6/8/8/8 w - - 0 1"]

```

Even with White to move, the game is lost. OK, but according to what rule/principle?

With 1. Kc3

* I'm able to get first to one of the key squares (c3,d3,e3)
* I get the diagonal opposition with the black King
* I can occupy the black's promotion square before the black's King

In spite of all that, the ending is lost. Is it because I can't keep the oposition?

p.s. The point of all this is to be able to evaluate this basic position only by applying rules, not having to calculate the concrete variations.

# Answer
> 12 votes
If you want to evaluate this ending with general rules, the rule of key squares is a good way to deal with it. However, this rule doesn't say "whoever reaches a key square first will get the result he is aiming for", it says "if the offensive king (here, Black) reaches one of the key squares, he will win."

Here after 1.Kc3 Ke4 2.Kd2 Kd4 you cannot prevent Black's king to reach one of the three key squares, so you lose.

```
[FEN "8/8/8/3pk3/1K6/8/8/8 w - - 0 1"]

1.Kc3 Ke4 2.Kd2 Kd4 3. Kc2 (3. Ke2 Kc3) Ke3

```

# Answer
> 6 votes
> The point of all this is to be able to evaluate this basic position only by applying rules, not having to calculate the concrete variations.

Well, the basic rule of (single) pawn endings is that if the side with the pawn manages to get their king on one of the key squares (and the pawn can't be taken on the next move), it's a win.

> I'm able to get first to one of the key squares

It doesn't matter that you're the first one to get there, that's probably where your mistake lies.

# Answer
> 2 votes
The diagonal (or horizontal) opposition doesn't do anything for you here because it doesn't help you prevent the black king from controlling the promotion square. If you slide down the c file, keeping the diagonal opposition, the black king just slide down the e file until it reaches e2, and then the pawn can simply march forward. And if you move your king to the d file, the black king can get the vertical opposition, forcing you to move out of the way until again it reaches e2 or c2, controlling the promotion square.

You could draw if you could get to the d file with the opposition, and without the pawn having extra tempos, but that would require black to blunder, for example 1.Kc3 Ke4 2.Kc2 Kd4?? 3.Kd2.

I guess the bottom line is that "not all oppositions are created equal", and often you do need to look at concrete variations anyway. Opposition is a tool, but what really matters here is getting control of the promotion square.

# Answer
> 0 votes
The reason why he can't stop you from reaching the key squares is because he cannot prevent you from gaining the opposition (while your pawn is still behind you).

# Answer
> 0 votes
A simple rule of thumb for king and pawn endings is that when the king is in front of the pawn then it is a win. The reason is that king will be able to gain opposition.

# Answer
> 0 votes
```
8/8/8/3pk3/1K6/8/8/8 w - - 0 1

1.Kc3 Ke4 {You lose control of one of the key squares, as the following variations show.} 2.Kd2 (2.Kc2!? {Setting up a trap.} Ke3! (2...Kd4?? 3.Kd2! {Drawing, although the position would lose if the first rank was removed:} 3...Kc4 4.Kc2 d4 5.Kd2 d3 6.Kd1! {This move would be impossible if the first rank was removed, but White draws here.} (6.Ke3 {White would have to play this if the first rank was removed.} Kc3))) Kd4 3.Kc2 (3.Ke2 Kc3) Ke3 {And Black Wins.}

```

The replayer has moves with annotations.

A video could also clear things up, because it explains the blockade and how to remove it.

---
Tags: endgame, pawn-endgame
---


# Question
Title: What do advocates of the QGD exchange variation (from the white side) recommend against alternative move orders?
I've recently started to become interested in the exchange Queen's Gambit Declined (QGD) from the white side:

```
[fen ""]
1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5 exd5 5.Bg5

```

Thematically speaking it's very enjoyable to play. The problem I'm noticing in constructing my repertoire is that black has a couple of move-order tricks up his sleeve to completely avoid this. For one, there's the Alatortsev Variation (1.d4 d5 2.c4 e6 3.Nc3 Be7), however white still has several interesting lines here after 4.cxd5 exd5 5.Bf4 with some highly dynamic Carlsbad structures. The second move order trick however seems a bit trickier to deal with:

```
[fen ""]
1.d4 Nf6 2.c4 e6

```

It seems to me as though this essentially forces white to choose between accepting the possibility of a main line QGD (after 3.Nf3 d5 4.Nc3) or the possibility of a Nimzo-Indian if white tries 3.Nc3 in hopes of achieving the exchange variation:

```
[fen ""]
1.d4 Nf6 2.c4 e6 3.Nc3 Bb4

```

While I do have some preparation against the Queen's Indian and Bogo-Indian Defenses, the problem here is that this move order seems to force me to study an entirely new system: either the main line QGD (with its endless amount of theory) or the Nimzo-Indian (also very heavy in terms of theory).

So my question is the following: do advocates of the exchange QGD recommend to book up in main lines of the QGD, to book up in the Nimzo-Indian, or to head in a completely different direction with something like 3.g3 (heading into the Catalan, also a very theoretical opening)? Which of those (and which variations therein) are most likely to have thematically similar play as the QGD exchange?

# Answer
> 1 votes
Indeed, the Exchange QGD and a system against the Queen's Indian do not blend very well.

In his famous repertoire series on 1.d4, GM Avrukh opts for the Catalan, using the move orders 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Nf3 and 1.d4 d5 2.c4 e6 3.Nf3. For more information, see Volume 1A (published in 2015) and Volume 1B (published in 2016).

Instead, the repertoire presented by GM Schandorff in "Playing 1.d4" (published in 2012) might be more to your taste. In the volume about the Queen's Gambit, he discusses the Exchange QGD. In the volume about the Indian Defences, the author recommends to play 4.e3 against the Nimzo-Indian.

---
Tags: opening, queens-gambit, nimzo-indian, queens-gambit-declined, catalan
---


# Question
Title: Is the queens gambit declined getting more popular than the slav?
Back when I used to study chess, like 10 years ago or so, all the text books and all the super GMs recommended either the slav or the semi slav against queens gambit, they said it's better than the queens gambit declined.

Moreover all recommended to avoid the queens gambit all together because it doesn't give white any advantage, and so many GMs just stopped playing d4.

Fast forward to now, I stopped studying chess, and I see everyone (by everyone I mean super GMs) playing d4 and black replying by playing queens gambit declined.

It's pretty much automatic for Caruana to play the declined and everyone is playing queens gambit, see the last FIDE championship and more.

What has changed? I feel like there's a big change in the text books nowadays, I don't know for sure, I haven't studied theory in ages.

# Answer
It seems to be that the QGD is regaining some popularity at the top level due to theory advancing. I don't think that says anything about the overall popularity of the two openings though (i.e., including all players).

The increase in engines' powers have made playing the semi-slav a very treacherous choice. There's a lot more that super GMs need to know now in order to stay in the game. Meanwhile, the slav can result in Black getting squeezed, and in general super GMs avoid openings like this. The QGD can be thought of as a safe "middle-ground", in which Black can gain equality with a bit of precise play. This is the kind of Black opening that many super GMs tend to like nowadays.

Overall though, none of these openings have lost any validity at the non-top level.
> 7 votes

---
Tags: opening, theory, queens-gambit, slav-defense, queens-gambit-declined
---


# Question
Title: To earn a direct title for coming first in an official FIDE tournament, do we include players who already have that title?
I'm intending to play in the Oceania Zonal tournament (brochure) and direct titles will be awarded in this tournament. I'm interested in the WIM title. The FIDE handbook says in regards to the WIM title:

> **Sub-Continental Individual**
> 1st equal – title;
> Silver & Bronze – norm
>
> 1st equal = best 3 players after tiebreak;

The current list of entries are here and it includes WGM Julia Ryjanova (2308) and IM Irina Berezina (2109) who are much stronger than me. Both players, however, already have titles higher than the WIM title, and I would like to know if they "count" for awarding direct titles. Do I need to score at least as much as them?

**Question**: To earn a direct title for coming first in an official FIDE tournament, do we include players who already have that title?

Layla Timergazi (FIDE) received the WIM title at the last Oceania Zonal, but she was outright first (crosstable).

# Answer
> 7 votes
Yes, we include all the players who participated in the event. If you finish second after WGM Ryjanova, you will receive a norm but not the title. If you finish fourth, you receive neither, regardless of who is on the podium. If the level of the field is high with a lot of tilted players participating, it often occurs that no 'special' title is awarded at the end of the tournament.

For instance, the World Junior champion is awarded with a grandmaster title. This year, the tournament was won by Iran's Parham Maghsoodloo, who was already a GM. The first non-GM in the tournament, IM Sergei Lobanov, did not receive that title instead (he 'only' got a GM-norm for his third place).

---
Tags: titles
---


# Question
Title: Can a win be claimed on the second illegal move if the first wasn't raised?
First of all, I don't *think* this is a duplicate of what happens on the first illegal move in a game. This is what happens after the *second* if the first is unclaimed.

The setting is a tournament under FIDE rules (2018).

**Can a win be claimed after the second completed illegal move completed by one side, if neither player nor the arbiter intervened upon the completion of the first?**

Assume the arbiter was summoned by the claiming player, and sees the game and its score for the first time. Assume that both players recorded the moves faithfully, illegalities included, such that they agree on the history of events and that there is no doubt that more than one illegal move was completed. (See below for an example.)

The relevant articles of the FIDE Laws of Chess seem to be:

> 7.5.1 **An illegal move is completed once the player has pressed his clock**. If during a game it is found that an illegal move has been completed, the position immediately before the irregularity shall be reinstated. If the position immediately before the irregularity cannot be determined, the game shall continue from the last identifiable position prior to the irregularity. Articles 4.3 and 4.7 apply to the move replacing the illegal move. The game shall then continue from this reinstated position.

And

> 7.5.5 After the action taken under Article 7.5.1, 7.5.2, 7.5.3 or 7.5.4 for the first completed illegal move by a player, the arbiter shall give two minutes extra time to his opponent; **for the second completed illegal move by the same player the arbiter shall declare the game lost by this player**. However, the game is drawn if the position is such that the opponent cannot checkmate the player’s king by any possible series of legal moves.

As a concrete example, look at the following game and assume the arbiter was summoned after the move 24. 0-0-0. Both players recorded the game and agree the game score is correct.

```
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1 "]
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nf6 4. Nc3 Bb4 5. Bxc6 bxc6 6. d4 exd4 7. Nxd4 Ba6 8. O-O d5 9. exd5 cxd5 10. Re1+ Ne4 11. Qg4 Qf6 12. Bg5 Qg6 13. Qf4 O-O-O 14. Bxd8 Rxd8 15. f3 Nxc3 16. bxc3 Bxc3 17. Reb1 Bxa1 18. Rxa1 Kd7 19. Qf5+ Ke8 20. Qxg6 hxg6 21. Nc6 Ra8 22. Kf2 O-O-O 23. Ke1 Re8+ 24. O-O-O

```

(Aside: this is probably a plausible game between weak players, so the question has maybe more than academic value.)

The illegal moves are `8.0-0`, `13...0-0-0`, `22...0-0-0` and `24.0-0-0`. (Relevant articles of the Laws: 3.8.2.2.1 for the first three, 3.9.1 for the last.)

* **Black attempts to claim a win under 7.5.5. Does this stand?**
* **Could white have claimed a win had she summoned the arbiter after `22...0-0-0`?**
* Extension: if the claimed win(s) does (do) not stand, under 7.5.1, from which position does the game resume?

# Answer
> Black attempts to claim a win under 7.5.5. Does this stand?

No. According to 7.5.5 -

> After the action taken under Article 7.5.1, 7.5.2, 7.5.3 or 7.5.4 **for the first completed illegal move by a player, the arbiter shall give two minutes extra time to his opponent**; for the second completed illegal move by the same player the arbiter shall declare the game lost by this player.

After the first illegal move the arbiter gives the opponent an extra 2 minutes. He will also explain his decision to the two players and warn the player that a second illegal move will lose the game. Punishment for a second illegal move can only occur if the punishment for the first illegal move has been made.

There are recent judgements (for which I don't have reference to hand, but I suspect came from one of the FIDE Arbiters Magazines) saying that only one illegal move can be punished at a time. For instance, if a player promotes illegally by not replacing the pawn while still in check, he can not be punished for two illegal moves.

Therefore after the first reported illegal move only the punishment for a first illegal move can be applied. Another illegal move must occur for the punishment for a second illegal move to be imposed.

> Could white have claimed a win had he summoned the arbiter after 22...0-0-0?

No, the same arguments apply.

> Extension: if the claimed win(s) does (do) not stand, under 7.5.1, from which position does the game resume?

From the position before the first illegal move. The punishment and reinstatement of the position are unrelated. Article 7.2.1 is relevant here -

> 7.2.1 If during a game it is found that the initial position of the pieces was incorrect, the game shall be cancelled and a new game shall be played.

Regardless of fault or punishment the entire game should be played according to the FIDE Laws of chess.

Note, I had a very similar problem arbiting a tournament in 2014 when a player came to me to report a third illegal move by his opponent and claim the game. Since it was the first illegal move he reported I treated it as the first illegal move. Since the previous illegal moves had involved his opponent not getting out of check and the position corrected by the players at the time there was no need to go back beyond the current move.

PS Before tieing oneself into gender-anguished knots it is worth noting this line in the introduction to the FIDE Laws of Chess -

> In these Laws the words ‘he’, ‘him’, and ‘his’ shall be considered to include ‘she’ and ‘her’.
> 7 votes

---
Tags: rules, illegal-move, losing
---


# Question
Title: At what handicap are humans as good as computer?
It is well known that the best chess engines are now far stronger players than the strongest human players. But is it known what the smallest handicap is that makes them roughly equal?

# Answer
> 4 votes
No scientific studies on this that I know of, but chess.com has hosted some online matches between super GMs (like Nakamura) and top engines in the world (esp. Komodo if I recall correctly).

In these matches, the human GM is given one of the following odds from the starting position:

* An extra exchange (so rook for knight).
* The engine, playing Black, is missing its f7-pawn.
* White gets two extra moves on top of his additional right to go first (I think).

Each of these are approximately +2 for White. So it seems that at the top level for humans and engines, a +2 advantage is needed to ensure rough equality.

Pretty humbling if you think about it. Wait until they perfect machine learning with engines...

---
Tags: computer-chess, handicapping
---


# Question
Title: The computer said a game was drawn but I think it is won for me
It's white's move and the king can't move.

Why was this game drawn? I should have won it I think.

# Answer
> 3 votes
Welcome to the site. What you described is the definition of stalemate, not checkmate. The enemy king not being able to move anywhere (while it's not attacked) is stalemate. That's why the game was drawn.

For a checkmate, you'd need to trap the king *and* be attacking it at the same time.

If it seems weird that stalemate is a draw, you're not alone. The 3rd world champion Capablanca argued that stalemate be considered a win. Nevertheless, the rules of chess dictate otherwise.

---
Tags: endgame, stalemate
---


# Question
Title: Can we say for sure that Black's king has not moved?
The following position appears as the 7th puzzle of Raymond Smullyan's *Arabian Knights*, a book about retrograde analysis.

```
[FEN "3qk2r/p2pp1bp/bpp2n2/8/3N3Q/1PN1P1P1/P1PPP2P/3K1n2 w - - 0 50"]

```

The conditions given are that "both \[of White's\] castles \[rooks\] captured on the same row, Black\['s\] queen's castle \[rook was\] captured by a pawn, and king's bishop given as odds." The stipulation is that you must find where White's rooks were captured.

I puzzled over this for quite some time, then gave up. Very early in the solution, it is stated that "Since the Black king has not moved..." However, I do not see how this can be inferred from the position. Is it necessarily true? Couldn't the Black king and queen have moved out of the way of the Black rook (which was captured on e3), and then moved back? I do not see "non-movement of the Black king" among the conditions or anything about Black being able to castle.

# Answer
> 11 votes
The conditions you gave are incomplete. The conditions include that black (to move) can castle; it's hidden in Smullyan's original problem text.

From the English book, last paragraph of the problem statement:

> Just then, however, news came that Black was about to castle. \[...\]

A clearer problem statement from the Retro Corner:

> Schwarz (am Zuge) darf noch rochieren. \[...\]

*Black (to move) can still castle.*

# Answer
> 4 votes
The convention in chess studies and problems is that:

* Castles are *always* allowed but if retrograde analysis can prove otherwise, i.e. that rook or king have already moved.
* En passant captures are *never* allowed but if retrograde analysis can prove the opponent's last move was the double-step pawn move required.

In Smullyan's problem, if it is possible to reach the position without moving black king nor rook, then you should assume Black still has castling rights.

**However**, this in itself doesn't prove that the Black King has never moved. Can you show us more of the given conditions and solution ?

---
Tags: problems, retrograde-analysis
---


title: What plan should white play with?

text:
# Question
Title: What plan should white play with?
It's black's turn. What plan should white use so as to confirm it's win? Thanks!

```
 [fen "r1b5/ppkn3R/3p2p1/8/N2b1B2/8/P1P2PPP/5RK1 w - - 0 50"]

```

# Answer
> 2 votes
White is an exchange up with a much safer king and more active / developed pieces. There are many ways to win. The most straightforward here is to exchange pieces where and queen a pawn.

---
Tags: planning
---


title: Regarding Chessbase softwares

text:
# Question
Title: Regarding Chessbase softwares
I have bought Houdini 6 pro ( ChessBase version ), for the primary purpose of practising by playing games against Houdini 6 pro (and other engines I own) I cannot figure out how to play a game against it (Not friendly game with dumbed down engine) . I want to play games with the engines full capacity (using ChessBase GUI) Is this possible or is ChessBase just a database program. Thanks in advance.

# Answer
Chessbase is indeed *just* a database program, albeit a very powerful one. If Houdini doesn't already provide it then you will need some kind of front end to play games against it.

One of the best free ones is Scid vs PC. This is available for download on Sourceforge and if you need more help getting started with it then there is much useful information on the Watford Chess Club website. There it explains in great detail what you need to do to get Scid to use other engines like Houdini.
> 1 votes

# Answer
You cannot play games against engines in ChessBase. ChessBase is just a database program.

ChessBase community has released DeepFritz which is also a GUI where you can play even rated games with the engine you want.

Deep Fritz 16 is the latest version of it. Check https://en.chessbase.com/post/fritz-16-your-companion-and-trainer for more information.
> 0 votes

---
Tags: engines, software, uci, chessbase, houdini
---


# Question
Title: How do I determine who has white or black?
I have used e.g. the game of paper, stone and scissors. Is there another method which determines who has white or black? If so, what is the method?

# Answer
White always moves first. To determine who plays white in a friendly game, you can:

* Toss a coin
* Roll a dice
* Play an even number of games, alternating sides
* Play rock-paper-scissors
* One player takes a white pawn and black pawn, and secretly places one in each hand. The other player picks the hand and therefore the colour to play
* Use any other agreed method

In tournament play, who plays which colour is determined by the organisers and you should be informed of which colour to play before each game. If you are unsure, ask an arbiter or an organiser for clarification.

Please note that *the initiative* is a specific chess term defined below:

> Initiative in a chess position belongs to the player who can make threats that cannot be ignored.

Source: Wikipedia
> 3 votes

# Answer
Another way is to bet for black in an armageddon setup (draw means win by black).

For example, white will have say 60 min. Players bet for the time allowance of black. Whoever offers least amount plays black with that amount of time.
> 2 votes

# Answer
The chess set I have here in front of me the pieces are both in black bags so someone picks one bag and that is what they play. I just realized this.
> 1 votes

# Answer
* Pawn hand - you hold a white pawn in one hand and black pawn in the other. Your opponent picks a hand, and the color of the pawn he gets is the color he plays.
* Flipping a coin.
* Randomly generating a number x in a set of n numbers. If x is a number in the first half of the set, you go first. Else, your opponent goes first.
> 0 votes

---
Tags: rules
---


# Question
Title: What's the benefit of using books during correspondence games?
I'm playing daily games on chess.com and read that it's officially allowed to use books or databases during the game.

My question is: How does it help me getting better (if it's the purpose of this allowance) to use theory sources in daily games?

# Answer
What you get from the books/databases during your correspondece games is the same as what you get when you read them generally. You can make use of

* Opening lines, which become more important as the games get slower and slower
* Tactics, which you may encounter during your games
* Positional concepts and maneuvers, which play the most important part of a correspondence game
* Endgames, though usually tablebases (7-man) are allowed in correspondence games.

All of these (not including tablebases) are allowed because they are simply undiscoverable in a cheating investigation (for example, you can expect perfect opening play from any player), as well as to help you, as you stated.
> 2 votes

# Answer
Using theory sources like books just saves you having to do the theoretical research yourself. So it'll help you win more correspondence games, but not necessarily improve your skills.

On the one hand, using theory books teaches you what high-quality opening play looks like. On the other hand, you're not really thinking yourself.

I would recommend spending time thinking what to play on your own. After you've reached a decision, *then* check the book to see how your move and theirs compares. After that, play whichever move you prefer.
> 1 votes

---
Tags: online, correspondence-chess
---


# Question
Title: Weird early f4 suggested by engine (English Opening: Reversed Sicilian)
I have played a game recently and at move 7 the engine suggested f4 as best continuation, but I failed to understand why. When I see the move, all I see is a super weakening move, especially with a lot of pieces on board. What might be the idea(s) behind this move ?

```
[FEN ""]

1. c4 e5 2. Nc3 { A21 English Opening: King's English Variation, Reversed Sicilian } Bc5 3. Nf3 Nc6 4. Nxe5 Nxe5 5. d4 Ng4? { (0.43 → 2.98) Mistake. Best move was Bd6. } (5... Bd6 6. c5 Be7 7. dxe5 Bxc5 8. Bf4 Ne7 9. e3 Ng6 10. Bg3) 6. dxc5 Qf6 7. Ne4? { (3.17 → 1.96) Mistake. Best move was f4. } (7. f4 Qc6)

```

# Answer
It is either f4 or f3 to defend the threat on f2. Intuitively I prefer the tempo that f2-f3 gets, but the idea of f2-f4 with e2-e4-e5 is probably what the computer likes.
> 4 votes

# Answer
Here, f4 is a good move. Because you can move e4 in near future. Then it will be a better position for you. You are dominating on centre. Before you move e4, it is hard to push d5 by black because three of your pieces already attacking d5. So it is hard to black to stop you moving e4.
> 1 votes

# Answer
If you ask yourself: Why is Ne4 bad? the answer will reveal itself. The only moves are Ne4, f4 and f3 to meet the threat Qxf2+.

As to your comment, "There are a lot of pieces of the board." I don't see any pieces? There is only a White Knight, a Black Queen and a Black Knight. The bishops and rooks are away on vacation...
> 1 votes

# Answer
7.Ne4 places the knight in an awkward position and makes it a target. After 7...Qe5 8.Qd5 Ne7 9.Qxe5 Nxe5, White is definitely better but Black's g4-knight has safely regrouped.

The point behind 7.f4 is to stop Black from moving his knight to the e5-square, while simultaneously neutralizing Black's attack on f2. Now White is ready to take up the whole centre with 8.e4. Another idea White has at his disposal is 8.Nd5, since the knight is still on c3 and not on e4.

7.f4 only looks weak temporarily. Once the e-pawn reaches e4, it looks very strong.
> 1 votes

---
Tags: english-opening
---


# Question
Title: Can a tournament director nullify a game in progress?
Recently I was at a USCF tournament. Six moves into my first round game, the tournament director came to my board and had me stop my clock. It turned out that the person across from me had the wrong board - he was actually supposed to be at the same-numbered board in a lower section (which was playing in the same room.) And the opponent I was supposed to play had sat down at the board in the lower section.

The TD stated that he was nullifying those two games in progress, and that those clocks should be reset and those games restarted with the proper opponent.

Is this the proper action? Can a game in which multiple moves have been played be simply nullified? Also, since my opponent was not at the correct board at the start of the round, and I was, and I properly started the clock, should some time have elapsed from his clock when we restarted?

# Answer
In FIDE rated tournaments I remember hearing that if the starting position was set up wrong and roughly \<= 6 moves were played, the game could be restarted. So if this tournament was also FIDE rated, FIDE rules take precident and restarting was fine. If this tournament was just USCF rated I'm not sure (you'd have to look up the official handbook).

I agree that some time should have elapsed for your opponent. You did nothing wrong but he did. However, you'd have to have said this during the game.
> 1 votes

---
Tags: rules, uscf
---


# Question
Title: What is the longest professional chess game that ended in a checkmate?
Quite simply, what is the longest professional chess game that ended in a checkmate?

# Answer
> 9 votes
The game Dann-Kovchan ended with 217...Nc2#.

```
[Title "Matthias Dann-Alexander Kovchan, Dresden Open, Dredsen Germany, 4/8/17"]
[FEN ""]
[startply "433"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 Ng4 7. Bg5 h6 8. Bh4 g5 9. Bg3 Bg7 10. Qd2 Nc6 11. Nb3 b5 12. h4 gxh4 13. Rxh4 Nge5 14. Nd5 Ng6 15. Rh1 Bxb2 16. Rd1 Bg7 17. c4 Rb8 18. c5 Nge5 19. Nf4 Bg4 20. Be2 Nc4 21. Qc1 Bxe2 22. Kxe2 Bb2 23. Qb1 Qc8 24. cxd6 exd6 25. Nh5 Rg8 26. Kf1 Rg6 27. Bxd6 Qg4 28. Bg3 Rd8 29. Rxd8+ Nxd8 30. Nf4 Rc6 31. Rh4 Ne3+ 32. Kg1 Qd1+ 33. Qxd1 Nxd1 34. Nd5 Nc3 35. Nd4 Rg6 36. Nf5 Nxa2 37. Nxh6 Nc3 38. Nf5 Ne2+ 39. Kf1 Nxg3+ 40. Nxg3 Kd7 41. Ne2 a5 42. Nec3 Rc6 43. Nxb5 Rc5 44. Na7 Bd4 45. Ke2 a4 46. Nb6+ Kc7 47. Nxa4 Ra5 48. Rh3 Bxa7 49. Nc3 Kd7 50. Rd3+ Ke8 51. Rd2 Nc6 52. g3 Rc5 53. Nd5 Rc4 54. Kf3 Kf8 55. Kf4 Kg7 56. Kf3 Nd4+ 57. Kg2 Ra4 58. e5 Ra5 59. Ne3 Rxe5 60. Ra2 Re7 61. Nd5 Rd7 62. Ne3 Ne6 63. Nf5+ Kf6 64. Nh4 Bc5 65. Nf3 Rb7 66. Nd2 Rb4 67. Rc2 Bb6 68. Ra2 Nc5 69. Ra3 Kg6 70. Rc3 f6 71. Ra3 Nd7 72. Rb3 Rd4 73. Nf3 Rd5 74. Rb2 Ba5 75. Re2 Nc5 76. Re7 Bd8 77. Nh4+ Kh6 78. Re8 Kg7 79. Re2 Nd3 80. Re6 Kf7 81. Ra6 Be7 82. Ra7 Ke6 83. Ra6+ Bd6 84. Rb6 Kd7 85. Rb7+ Bc7 86. Ra7 Nc5 87. Ra2 Bb6 88. Rb2 Ba5 89. Rb5 Bc3 90. Nf3 Kc6 91. Rb8 Ne6 92. Rc8+ Nc7 93. Rb8 Ra5 94. Ng1 Ra2 95. Nh3 Nd5 96. Re8 Be5 97. Kf3 Kd7 98. Rg8 Ne7 99. Rf8 Nf5 100. Rf7+ Ne7 101. Rf8 Ke6 102. Re8 Bc7 103. Rh8 Nc6 104. Re8+ Kf7 105. Re4 Bb6 106. Kg2 Ne5 107. Kf1 Nd3 108. Re2 Ra1+ 109. Kg2 Bc5 110. Kh2 Ne1 111. Ng1 Bb4 112. Rb2 Bc3 113. Re2 Ra5 114. Nh3 Rh5 115. Re3 Ba5 116. Ra3 Rb5 117. Ra2 f5 118. Re2 Kf6 119. Ra2 Bb6 120. Re2 Rb1 121. Ra2 Nd3 122. Kg2 Nc5 123. Nf4 Rd1 124. Rc2 Rd6 125. Rb2 Nd7 126. Ra2 Kf7 127. Rb2 Bc5 128. Rc2 Rd1 129. Re2 Bd6 130. Nh3 Nf6 131. Ra2 Ne4 132. Rb2 Ke6 133. Re2 Kd5 134. Ra2 Rb1 135. Ra5+ Nc5 136. Ra2 Rd1 137. Ng1 Ne4 138. Ne2 Ke6 139. Rc2 Ra1 140. Nd4+ Ke5 141. Ne2 Kf6 142. Ng1 Ra5 143. Nh3 Ke6 144. Ng1 Kd5 145. Nh3 Kd4 146. Rb2 Kd3 147. Rb3+ Kd4 148. Rb2 Ra7 149. Rb5 Bc5 150. Rb2 Kc3 151. Re2 Bd6 152. Re3+ Kd4 153. Ng1 Kd5 154. Re2 Ra3 155. Rb2 Bc5 156. Nh3 Kd4 157. Re2 Bd6 158. Ng1 Kc4 159. g4 Ra8 160. gxf5 Rg8+ 161. Kf1 Kd5 162. Nf3 Bc5 163. Nd2 Nd6 164. Nf3 Rg4 165. Re5+ Kc6 166. Ne1 Bd4 167. Ra5 Bb6 168. Re5 Bd4 169. Ra5 Nc4 170. Ra6+ Bb6 171. Nd3 Rg5 172. Ra4 Nd6 173. f6 Nf7 174. Re4 Bd8 175. Ke2 Kd5 176. Re8 Rf5 177. Re3 Rxf6 178. Rf3 Re6+ 179. Re3 Rh6 180. Nf4+ Kd6 181. Rh3 Rf6 182. Nd3 Bb6 183. Rh5 Nd8 184. Rb5 Kc6 185. Re5 Ne6 186. Nb4+ Kd6 187. Rd5+ Kc7 188. Nd3 Bxf2 189. Rh5 Bb6 190. Rh7+ Kd6 191. Rh5 Nd4+ 192. Kd2 Re6 193. Kc3 Nc6 194. Kd2 Ba5+ 195. Kd1 Re3 196. Nc1 Ne5 197. Rh2 Kd5 198. Re2 Rh3 199. Kc2 Nc4 200. Re7 Rc3+ 201. Kb1 Bb4 202. Re2 Rh3 203. Kc2 Rc3+ 204. Kb1 Bd6 205. Na2 Ra3 206. Nc1 Bf4 207. Na2 Rb3+ 208. Kc2 Rb2+ 209. Kd1 Ne3+ 210. Kc1 Rb3 211. Rd2+ Ke4 212. Rd8 Bg5 213. Rg8 Bf6 214. Ra8 Kd3 215. Ra4 Bb2+ 216. Kb1 Ba3+ 217. Ka1 Nc2# 0-1

```

---
Tags: checkmate, records, master-games, famous-games
---


title: Pawn Structure database

text:
# Question
Title: Pawn Structure database
I wonder if there is any existing or a way to create a chess database organised *only* according to pawn structures, where the notion of a pawn structures is crudely defined by GM Andrew Soltis in his book Pawn Structure Chess and GM Mauricio Flores Rios in his book Chess Structure: A Grandmaster Guide as shown in this Wikipedia article?

https://en.wikipedia.org/wiki/Pawn\_structure

I have the first book and I read a free excerpt of the second.

The software I am currently using is SCID vs PC.

# Answer
In SCID, from the Game List you can select the "Change filter" icon followed by the "Search for material or board patterns" icon. In the window that pops up, you can select the location of up to ten pawns. Although ten is not enough to specify the pawns of both sides, you can also separately specify the number of pawns each side has.

You can also select just the file and not the rank (for example, you might care that your a-pawn exists, but not about its exact location.) And you can specify that a particular file doesn't have any pawns of a particular color. Here's what the screen can look like:

In this example, for a game to match the filter, Black must have pawns on b7, c6, e6, f7, and g7, no pawn on the d-file, and exactly seven pawns. Additionally, White must have pawns on c2, d4, and f2, with no pawn on the e-file, and exactly seven pawns.
> 2 votes

---
Tags: software, database, pawn-structure
---


# Question
Title: How well does Elo rating estimate a player's strength?
Proposal: strength is the **real** and rating is the **model** that estimates it.

Question: How well does Elo rating estimate a player's strength?

Bonus question: What happens if you take the player's rating curve into account?

# Answer
> 4 votes
The Elo rating is a statistical prediction of your results against players with known rating when they play each other in the long term. Some examples:

* Two players with the same rating will score the same amount of victories when playing together.
* Two players with a 200 Elo difference, means the stronger player will win 3 out of 4 games (and lose the other).
* Two players with a 400 Elo difference, means the stronger player will win 10 out of 11 times (and the weakest winning the other one).
* And so on, a difference beyond 700 is not accurately measurable (basically the system predicts 100% score of the stronger player).

Now, in practice, many other factors come into play (ie. the stronger player being bored or overconfident, playing a system in which the weakest players has in-depth knowledge, being in shape, etc.)

For more details, see

https://thechessworld.com/articles/general-information/deeper-look-at-elo-chess-rating-system/

http://en.wikipedia.org/wiki/Elo\_rating

# Answer
> 5 votes
It's not clear to me whether you are asking a philosophical or a quantitative question.

My answer to the philosophical question is that the Elo rating is predictive; that is, it is designed to make accurate predictions about the outcomes of chess games. To that extent, it measures strength by estimating the likelihood that a player will win against another player. It does this by using the player's past results, and it does the best it can given that information.

The answer to the quantitative question is that the "expected value" of a game between two players is correlated with the difference in their Elo ratings. For example if player A's Elo rating is 200 higher than that of player B, then player A would be expected to go about 76-24 over the course of a 100-game match.

*Note*: The question has changed since I answered it, so my answer makes less sense now. The title of the question used to be **Does the chess rating represent a player's strength?**, and the question was "I notice that somehow, we chess players associate the chess rating with strength. But is it a measure of strength? To what extent?" Please take this answer as a response to that question, not the one it has been changed to.

# Answer
> 2 votes
"Normally" (pun intended) the Elo rating does indicate a player's **average** strength (you tagged this post with Elo, so I am considering Elo rating).

Elo rating assumes that a player's performance conforms to what is called the Normal Distribution. Thus, if your rating is **2700**, then that's your **mean** or average level of performance. However, ***that does not give an indication of how far varied your performance can be in relation to your mean rating***.

For instance, if your **standard deviation** is low, then it means that your performance is very consistent around 2700 (for example, you beat most guys below 2600, hardly ever beat 2800+, and usually draw with players between that range). If your standard deviation is high, then it means that sometimes, you beat even Magnus Carlsen (2881 as of today), but at times you find yourself losing to a low rated Grandmaster or even an International Master.

# Answer
> 2 votes
The Elo rating system doesn't estimate a player's strength as well as other systems. I've read a while ago about a contest between rating systems, I'll describe it by quoting the article: `competitors train their rating systems using a training dataset of over 65,000 recent results for 8,631 top players. Participants then use their method to predict the outcome of a further 7,809 games.`

The conclusion:

`The Elo benchmark was outperformed within 24 hours`

On a sidenote, I can't see the charts anymore, if anyone finds them, you're welcome to contribute them. From what I remember there were no less than 60 rating systems which outperformed Elo.

# Answer
> 1 votes
The weakness of the Elo rating system is that it depends on scoring, that is the assignment of win=1, loss=0, and draw=1/2. Scoring causes some information about chess game outcomes to be lost. It would be more accurate to measure chess playing strength in two dimensions. Please see: http://papers.ssrn.com/sol3/papers.cfm?abstract\_id=2477868

# Answer
> 1 votes
An Elo rating most emphatically is NOT a measure of a player's strength, nor was it intended to be. A player might, for all kinds of reasons, have a lower Elo rating than someone that is in reality weaker. For example a player that plays mostly in team competitions might accept a draw in a winning position, or risk losing by playing for a win in a drawn position, with bad effects on their rating.

Another example: One player in SWISS tournaments might play objectively to get the "correct" number of points that their play deserves. Another might take great risks on the grounds that 3.5 or 4 out of 6 finishes nowhere whereas 5 or more is usually in the money, and worth the risk of losing from an easily drawn position. The first player would probably earn a higher rating, but the second would win more tournaments! (and might actually be stronger).

The maths behind Elo ratings guarantees that rating points are gained more slowly than is warranted by current form and also ensures that a few bad results do not reduce a rating by a huge amount. In effect games played years earlier when a player was much weaker (or stronger) affect the rate at which the rating can change. This aspect of controlling the rate of change is further fudged by choice of k-factor.

A further problem is that Elo ratings only apply properly to players that are contemporary. They do not give meaningful comparisons of strength for players active in different eras. Of course that has not stopped people from making such comparisons and concluding (for example) that Lasker and ZUuckertort would hold their own against today's GM's that former world-champion Petrosian was no stronger than any modern-day top-50 super-GM, or that Fischer was significantly weaker than Kasparov and Carlsen. Those conclusions may or may not be true, but it is just wrong to use Elo ratings (retrospectively calculated as necessary) to arrive at them.

What Elo ratings are designed for is to allow the probability of encounters between players to be estimated. They do that quite well for players that have stable ratings that have not changed much over a few years. They do a poor job when one or both of the players is either improving or declining.

They have been adopted as a proxy for chess strength, but are far from perfect. The right way to assess strength is to study a players games and make a judgement, but to do that you have to be very strong yourself, and it is hard work.

As in so many other areas of life and human endeavour it is much easier to pretend that a simple number based on results tells us what we'd like to know ... even when it doesn't.

# Answer
> 1 votes
One interpretation of the question is "What is the standard error of Elo?" That is, if Elo is a statistic that measures some true latent ability, what is the standard deviation of that statistic? If, for example, you've just played 50 tournament games, and your Elo is calculated as 1700, is it really 1700, or might it actually be 1710? Or 1750? Might it be 1600?

I have analyzed this question in a blog post, the gist of which is as follows: Suppose two players play each other repeatedly. The difference in true abilities is "Delta A", where we assume the probability of a win by the first player is the Elo logistic function in Delta A. Then, after many games between them, the difference in their computed Elos will be Delta r which equals Delta a plus some error, epsilon. That error term, epsilon, approximately follows an autoregressive process, and is asymptotically unbiased. The standard error depends on the "k factor" used in updating Elo, and on the probability of a tie (which is typically higher for better players, when equally matched). Here is a plot of the empirical (dots) and theoretical standard error versus the k factor, for different probabilities of a tie:  The upshot is that differences in Elo will have standard error around 20 or more.

As others have noted, the Elo rating has some deficiencies. However, it is fairly simple to describe and compute, which was necessary at the time of its introduction.

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Tags: rating, elo, statistics
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# Question
Title: Why is this gambit also known as the Maltese Falcon Gambit?
Why is the Gibbins-Wiedehagen Gambit (1.d4 Nf6 2.g4) also known as the Maltese Falcon Attack (or Gambit)? Is there any specific reason for that?

# Answer
Humphrey Bogart was known to play this opening on a regular basis. Here is one of the recorded games with him playing the opening. One of Bogart's most famous movies is The Maltese Falcon, thus the Maltese Falcon Gambit or Attack.
> 5 votes

# Answer
Well, it's known as a gambit because Bc8 eyes on g4.

A common mistake is 1.d4 Nf6 2.g4? Nxg4? 3.e4 with initiative.

> The Maltese Falcon is a prime example of a story that, while important in its day, is lost on the current generation.

Named after Claude Bloodgood, the opening was played as the Bogart Poisoned Spike in the 30's.

Clearly it's lost on the current generation: 2.g4? Doesn't do anything to control the center. What will White do after 2...h6! 3.Bg2 c6, when Black will play solid and exploit White's weakness ten moves later?
> 3 votes

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Tags: opening, history, gambits
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title: AlphaZero’s search procedure

text:
# Question
Title: AlphaZero’s search procedure
I am aware of related questions and great answers on the same topic such as Understanding AlphaZero. My questions are related to the following figure on **AlphaZero's search procedure**

This figure comes from the Science paper on AlphaZero (Fig. 4, page 4). The search is illustrated for a position from the very nice game 1 AlphaZero (white) and Stockfish (black) after 29. ... Qf8. The rest of note of the figure is as follows

> The internal state of AlphaZero's MCTS is summarized after 10^2, ..., 10^6 simulations. Each summary shows the 10 most visited states. The estimated value is shown in each state, from white's perspective, scaled to the range \[0, 100\]. The visit count of each state, relative to the root state of that tree, is proportional to the thickness of the border circle. AlphaZero considers 30.c6 but eventually plays 30.d5.

I would appreciate some insights regarding the following questions. (Important to note that I am a mere chess player with no knowledge on computer science. I still find this fascinating)

1. What does represent the 10^2, ..., 10^6 simulations? I am very confused because in the Supplementary Material they note that \`\`During training, each MCTS used 800 simulations''.
2. What does it mean that each MCTS used 800 simulations?
3. I assume that the value of 60 in the red circle in the 10^2 simulations represents a 60% expected score for white, which is the average of all position evaluations. However, the simple average of the 9 moves shown is equal to 61.2. I guess that other moves also considered and simulated. Am I right here?
4. I assume that for simulations 10^3 to 10^6, they only present an illustrative sample of the branches. The simulation 10^5 is not shown after 34.Rce1 or stopped after 34.Rce1? I guess that each simulation goes until an expected score of 100%.

# Answer
The diagram shows the 10 most visited game states/positions that AlphaZero calculated. It's actually looking at thousands of positions, but they're only showing the 10 positions that it comes back to the most. For your questions:

1) AlphaZero's search algorithm is called Monte Carlo Tree Search (MCTS). The fundamentals of how it works when thinking at some game state:

* Pick a move. The way this move is picked is based off an algorithm favoring:
    + How good a move has performed in past random simulations of it.
    + How infrequently it has been picked (a move played out less ==\> more desirable).
* Follow this move to a new game state (i.e., the position that arises when you play the move).
* Repeat step 1, for some time limit or depth limit.

The move that has the best average score in all its playouts is the one that AlphaZero picks. There's more involved than this, but the above is the general idea of MCTS. So something like 10^2 simulations for the root node means that AlphaZero performed the above algorithm 10^2 times for that position.

The part where they mentioned "800 simulations" refers to when AlphaZero was learning (*before* its games with Stockfish). The way AlphaZero learns heuristics on its own (which allow it to accurately evaluate positions) is by playing itself over and over. So, I assume they mean that during this phase of playing itself, each time it thought on what to play in a position, it only performed 800 simulations from a position. The point of this was probably to have time to get more practice games in. Against Stockfish, playing extremely quickly is unnecessary, and AlphaZero may as well use the time it's been given to playout way more such simulations.

2) Explained above.

3) Yes, thousands of other moves are also considered, they just aren't shown in the diagram. Also, even if the 10 states shown were the only ones reached, you couldn't just average their scores out. The reason is that some game states are reached more often than others, and thus have a higher weight in the average calculation.

* To illustrate this, assume you only had two possible moves you could play in the beginning of a game: 1.e4 and 1.h4. Looking back at the MCTS algorithm I outlined, playouts/simulations on 1.e4 would happen more often since 1.e4 performs better. However, 1.h4 would also be picked once in a while due to how infrequently you look at it. So maybe you do 9 playouts on 1.e4 and get a score of 60%, while do 1 playout on 1.h4 and get a 0% score. Your odds of winning from the starting position are not (60% + 0%) / 2 = 30%, but rather (60% * 9 + 0% * 1) / 10 = 54%.

4) Yes, only an illustrative sample is shown since they only wanted to show the 10 most visited game states. I'm sure AlphaZero continued the MCTS algorithm far past 34.Rce1.
> 5 votes

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Tags: engines, alphazero
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