# Question
Title: Failing to understand how to start Popeye
I am trying to run the chess solving program Popeye, but I am failing to understand how to start the program on Windows.

There is an English guide, and this is all of what is tells you to do:

> Starting popeye:
>
> Change the name of your preferred executable to py.exe
>
> To operate it from the terminal: py
>
> To solve problems recorded in file XX: py XX

I'm basically illiterate when it comes to code. Can anyone explain how to start Popeye?

# Answer
> 5 votes
To ease the burden of typing, what I do is this: I have a file containing chess-related commands I have run. I keep this file in a directory I can easily find. Most times I want to do a chess-related command, it's a slight variant of one I ran earlier, e.g. to run Popeye on some other input file. So I'd replace the old input file name with the new one, resulting in something like this:

```
D:
cd "D:\games\by game\chess\problems\Popeye"
C:\Progra~1\Popeye\pywin64 Smith_h#3.pyin

```

`C:\Progra~1\Popeye\pywin64` is just where I installed the Popeye executable on my Windows PC. Replace this with whatever is the file name (including drive-letter and full path) of where you've installed the Popeye executable on yours.

The parameter `Smith_h#3.pyin` you see there is the name of the file which Popeye is to read. As it stands, that command would run Popeye, read that file and write its output to the command-prompt window. This is what that Popeye documentation was referring to when it said "To solve problems recorded in file XX". By XX they mean the name of the file in which you have written the Popeye commands that describe the problems(s) you want Popeye to solve. That Popeye documentation describes the Popeye commands which you need to put into the input file to describe a problem to Popeye.

If you want to capture this output in a file, here are two ways to do it. One is to specify the output file in the command, e.g.

`C:\Progra~1\Popeye\pywin64 Smith_h#3.pyin > Smith_h#3.pyout`

This would redirect output to `Smith_h#3.pyout` but would not write anything to the window while Popeye is running. Another is to put the Popeye command

`prot Smith_h#3.pyout`

in Popeye's input. This would redirect output to the specified output file *and* write it to the window as well.

# Answer
> 6 votes
For those interested, you can download the exe from https://sourceforge.net/projects/popeye-chess/

There's no reason to alter the name of the executable. You have to enter command prompt. On windows this is done by running cmd.exe, or you can use a dos emulator. When you're in the folder which contains the popeye.exe file, you can start the program by typing popeye. However, the program is "dumb" and you need to provide more parameters. The first parameter is the file which contains the puzzle(s). There are three other parameters, but they're not needed.

For example, the command "popeye puzzle.pgn" starts the popeye program and tells it to solve the puzzles in the puzzle.pgn file. The program should produce a generic file with the answer(s) and misc. info about what the program did.

There is another method, but that is more restrictive and not really worth mentioning.

This is the method on a Windows OS. For Linux, Apple, or other OS the procedure is slightly different, but users of these OSes normally are already familiar with these methods.

---
Tags: learning, software
---


title: Elo rating and fide rating

text:
# Question
Title: Elo rating and fide rating
I am an amatuer chess player and I want to know the difference between Elo rating and FIDE rating (for example, a 2500 Elo rating is needed for GM title).

# Answer
> 15 votes
The Elo rating system is a rating system for two-person, zero-sum games based on the assumption that performance is normally distributed. That is, a player's performance is expected to follow a normal distribution. For FIDE the mean = the player's rating and standard deviation = 2000/7 = 285.7.

It was developed by Arpad Elo and first implemented by the USCF at a meeting in St Louis (where else?) in 1960. So, the USCF rating system is the original Elo rating system. It was later adopted by FIDE in 1970. Many other federations also implement Elo rating systems and it is also used in other sports, for instance soccer.

It has since been discovered that players' performances are not strictly normally distributed. Lower rated players have a better chance of an upset result against higher rated players than their ratings suggest and so the basic system has been tweaked by different federations (including FIDE) over the years. Varying k factors are one variable that is changed.

Elo rating systems predict *relative* performance, not absolute performance. Hence FIDE, USCF, Lichess, Chess24 ratings, although all elo rating systems, are not comparable. All you can say is that if player A has a higher rating in one implementation than player B then you expect that in a different implementation player A will again have a higher rating than player B although it is not certain. The likelihood will depend on the difference in ratings and the standard deviations of the systems.

So, the bottom line is that Elo rating is a *system* of rating and FIDE rating is a particular *implementation* of Elo rating.

# Answer
> 12 votes
To make GM, a 2500 FIDE rating is needed, among other thing. But there is not a separate "Elo rating" which is also needed.

Elo rating is a generic term for any rating system based on the work of Arpad Elo. It's also often used as shorthand for FIDE rating. If someone says their rating is 2500 Elo, that normally means 2500 FIDE.

# Answer
> 4 votes
From your context, there is no difference between the two. "Elo" (From Arpad Elo, a professor at Marquette University and president of one of the two organizations that merged to form the US Chess Federation back in 1939 -- IIRC he chaired the meeting that resulted in the merger) when used by in the context of FIDE titles typically refers to the FIDE rating system. Professor Elo created the rating system used by FIDE, and was responsible for calculating the FIDE ratings in the initial years after its adoption. You can read a description of his original system in his book "The Rating Of Chessplayers Past and Present."

Professor Elo created his system with the numeric range it has in order to cause the least amount of disruption to the USCF, which was at the time using the Harkness system; his preference was for a two-digit system as he thought four digits implied a greater precision than the system was capable of.

It's not surprising that some who came later would tweak the system, given Elo's own view of its precision. But as he observed in his book, the real problem with any rating system is that it's trying to predict human behavior without taking into account factors that would affect it. As a measure of past performance it works. As a predictor of the outcome of a single game, it leaves too much out of the equation to be more than mildly indicative.

Edit: My memory was wrong. It was Elo's successor, Kirk Holland, that chaired the merger meeting.

---
Tags: rating
---


# Question
Title: Did Kasparov refute over the board Karpov's 1987 novelty?
In the second game of the 1987 World Championship, Kasparov played an English opening. In the ninth move Karpov played a novelty that he had prepared for his 1981 match with Korchnoi (the usual play is 9. ... exf3). It is claimed that Kasparov's next two moves, 10. d3 and 11. Qb3 completely refute Karpov's surprise move, but in the end Kasparov lost this game (it is the famous one in which he forgot to hit the clock after playing his 26th move).

Then in the fourth game, Kasparov plays an English again and reaches the same position up to move 8! Clearly it was a provocation, but whether he could refute 9. ... e3 or not was not demonstrated, because Karpov avoided it and played the usual 9. ... exf3, only to get trounced (incidentally, this was the 100th championship game between the two).

> What is the novelty about, and how do Kasparov moves refute it?

For reference, here are the two games:

```
[Event "World Championship Game 2"]
[Site "Seville, Spain"]
[Date "1987.10.14"]
[Round "2"]
[Result "0-1"]
[White "Kasparov"]
[Black "Karpov"]
[ECO "A29"]
[FEN ""]

1. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. g3 Bb4 5. Bg2 O-O 6. O-O e4 7. Ng5 Bxc3 8. bxc3 Re8 9. f3 e3 10. d3 d5 11. Qb3 Na5 12. Qa3 c6 13. cxd5 cxd5 14. f4 Nc6 15. Rb1 Qc7 16. Bb2 Bg4 17. c4 dxc4 18. Bxf6 gxf6 19. Ne4 Kg7 20. dxc4 Rad8 21. Rb3 Nd4 22. Rxe3 Qxc4 23. Kh1 Nf5 24. Rd3 Bxe2 25. Rxd8 Rxd8 26. Re1 Re8 27. Qa5 b5 28. Nd2 Qd3 29. Nb3 Bf3 30. Bxf3 Qxf3 31. Kg1 Rxe1 32. Qxe1 Ne3 0-1

```

```
[Event "World Championship Game 4"]
[Site "Seville, Spain"]
[Date "1987.10.19"]
[Round "4"]
[Result "1-0"]
[White "Kasparov"]
[Black "Karpov"]
[ECO "A29"]
[FEN ""]

1. c4 Nf6 2. Nc3 e5 3. Nf3 Nc6 4. g3 Bb4 5. Bg2 O-O 6. O-O e4 7. Ng5 Bxc3 8. bxc3 Re8 9. f3 exf3 10. Nxf3 Qe7 11. e3 Ne5 12. Nd4 Nd3 13. Qe2 Nxc1 14. Raxc1 d6 15. Rf4 c6 16. Rcf1 Qe5 17. Qd3 Bd7 18. Nf5 Bxf5 19. Rxf5 Qe6 20. Qd4 Re7 21. Qh4 Nd7 22. Bh3 Nf8 23. R5f3 Qe5 24. d4 Qe4 25. Qxe4 Rxe4 26. Rxf7 Rxe3 27. d5 Rae8 28. Rxb7 cxd5 29. cxd5 R3e7 30. Rfb1 h5 31. a4 g5 32. Bf5 Kg7 33. a5 Kf6 34. Bd3 Rxb7 35. Rxb7 Re3 36. Bb5 Rxc3 37. Rxa7 Ng6 38. Rd7 Ne5 39. Rxd6 Kf5 40. a6 Ra3 41. Rd8 Ra2 42. Rf8 Ke4 43. d6 Nf3 44. Rxf3 Kxf3 45. Bc6 1-0

```

# Answer
> 2 votes
No, this was unequivocally not refuted. First, I would consider a line "refuted" if it led to a significant advantage, and there was nothing you could do about it...it is forced. That is definitely not the case.

For a very brief moment in time, this appeared to be slightly better for white, but black has since found plenty of resources with Na5, and it has been played many times since, even by some very strong Grandmasters. One of the latest games is Nakamura-Naiditsch from 2018. Another recent game between two highly-rated players is Gelfand-Hammer Palma de Mallorca 2017 (1/2)

```
 [Event "Olympiad-43"]
 [Site "Batumi"]
 [Date "2018.10.02"]
 [Round "8.3"]
 [White "Nakamura, Hikaru"]
 [Black "Naiditsch, Arkadij"]
 [Result "1/2-1/2"]
 [ECO "A29"]
 [WhiteElo "2763"]
 [BlackElo "2721"]
 [PlyCount "73"]
 [EventDate "2018.09.24"]
 [EventType "team-swiss"]
 [EventRounds "11"]
 [EventCountry "GEO"]
 [FEN ""]

 1. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. g3 Bb4 5. Bg2 O-O 6. O-O e4 7. Ng5 Bxc3 8. bxc3 Re8 9. f3 e3 10. d3 d5 11. Qb3 Na5 12. Qa4 c6 13. cxd5 cxd5 14. f4 Bg4 15. Nf3 Nc6 16. h3 Bd7 17. Qa3 Nh5 18. Kh2 Qf6 19. Nd4 Nxd4 20. cxd4 g5 21. fxg5 Qxg5 22. Qd6 Bc6 23. h4 Qg7 24. Bh3 f5 25. Rf3 Rad8 26. Qb4 f4 27. gxf4 Qc7 28. Ba3 Nxf4 29. Qe1 Nxh3+ 30. Qg3+ Qxg3+ 31. Rxg3+ Kh8 32. Kxh3 Re6 33. Rf1 Rg8 34. h5 h6 35. Rxg8+ Kxg8 36. Kh4 Ba4 37. Bc1 1/2-1/2

```

In that game, black was never worse than the tiniest of white pluses that you see in every sound opening, and by move 19, black was actually better. In fact, per Mega 2020, in the 48 games played in this line since white won 16, black won 20, and 12 draws. The average rating for white was 2386, and for black 2410.

It would seem that this opening holds up quite well for black even to this day, and my modern computer with Stockfish agrees.

# Answer
> 3 votes
I recall these games from his Modern Chess series. Logically, if Kasparov was willing to return to the same position, Karpov believed that it was likely that Kasparov had found a line that resulted in a favorable position for White. Indeed, the moves 10. d3 and 11. Qb3 give White some advantage and Kasparov had a rather pleasant position throughout. Karpov probably didn't want to revisit this line as he knew he got lucky in the first game.

# Answer
> 1 votes
Kasparov took 63 minutes over his response to the ....e3 move, that in itself made the novelty a very worthwhile undertaking from Karpov's perspective. Clearly he found a gap in Kasparov's preparation and often that might be all one needs in a contest between two near equals, especially when the psychological factors are complex and significant.

---
Tags: opening, world-championship, novelties, english-opening
---


# Question
Title: Firouzja vs Kovalev: what went wrong for black in the opening?
In the first round of the ongoing Wijk aan zee Masters tournament, Firouzja won vs Kovalev. Apparently, right out of the opening white had gained a winning edge. In particular, somewhere around 16...c4 it seems to be where black went somehow wrong (computers also favoring white there). But from the opening point of view,

* how can Kovalev's 16...c4 be so bad that white has already a substantial edge? Was this a mix-up in the opening variations? First glance, it seems b5 is indeed weak as c4 frees d4 square for the knight, but can we not hold on to the b5 pawn differently? for example with Qb6?

Position at move 16:

```
 [title "Firouzja vs Kovalev 16...c4"]
 [fen "r2qrbk1/1b3pp1/p2p1n1p/1p1P4/Pnp1P3/5N1P/1P1N1PP1/RBBQR1K1 w - - 0 17"]

```

# Answer
> 7 votes
## tl;dr: Wrong move order by black in the opening: the c4 advance must be prefaced with Nd7 in the played Zaitsev variation.

That said, and although your hunch about the early `c4` is correct, I'm afraid there's no simple answer that immediately explains why the immediate `c4` is bad and why `Nd7` is so crucial, since the Ruy Lopez and the Zaitsev are highly theoretical openings and thus, all about nuances and concrete assessments.

*In any case, here's an attempt to answer it in a simplified manner.*

**Bit of context first:** the game started out as a classical Ruy Lopez which then transitioned into the Zaitsev variation. Then in particular after `11...Bf8`, Firouzja opted for the older system with `12.a4` which is a variation rich in theory dating specially back to the Kasparov-Karpov games (see e.g. 1990 games). Instead of `12.a4`, nowadays the more go-to and modern option is `12.d5.` So, seeing `12.a4` might have come as a bit of a surprise.

Fast-forwarding to the key moment of the opening, in the `a4` variation white often waits out the `d5` advance until black has played `c5.` Then after `15...c5 16.d5`

## the main and key move by black is to play `Nd7` (diagram below): which concretely prepares either options of `c4` or `f5`:

* `c4` (left diagram): with ideas of establishing either a knight or a protected advanced pawn on `d3`
* `f5` (right diagram): directly undermining the defense of the `d5.`

However, Kovalev played the immediate `c4` advance **without** the inclusion of `Nd7`, this was the **main inaccuracy**! The problem is black's losing a pawn in the all ensuing lines without any dynamic or positional compensation for it. Let's see some of these lines in the annotated diagram below:

```
 [title "16.c4 without Nd7"]
 [fen ""]
 [StartPly "33"]

 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3 O-O 9. h3 Bb7 10. d4 Re8 11. Nbd2 Bf8 12. a4 h6 13. Bc2 exd4 14. cxd4 Nb4 15. Bb1 c5 16. d5 c4 17. Nd4 {b5 pawn is attacked twice now} Nd7 {this is what happened in the game, but Nd7 here is too late} (17...Qb6 {an attempt to directly defend the pawn, but the queen ends up being completely misplaced as we'll see and too far away from the kingside.} 18. N2f3 {defending the d4 knight and preparing Be3} g6 19. Be3 Qc7 {side-stepping the discovery} (19...bxa4 {just for the sake of discussion, let's see how black loses by force if they do not side step the discovered threat and take on a4 instead} 20. Ne6 Qb5 21. Nxf8 Rxf8 22. Qd4 {and white's kingside attack is too much to parry as the king on g8 is defenceless}) 20. axb5 {winning the b5 pawn if black recaptures, so only chance is to take on e4 instead} Nxe4 21. Ne6 {and white's nearly winning already as black's position is collapsing after fxe6 Bxe4. Ne6 is a thematic move in these structures with the pawn on d5.} ) 18. axb5 axb5 19. Rxa8 Bxa8 20. Nxb5 Qb8 21. Na3 {c4 is falling next, as happened in the game} Nd3 22. Re3 Nxc1 23. Qxc1 g6 24. Naxc4 {rest of the game is not included here}

```

In contrast, here's how the variation usually continues when `c4` is prefaced by `Nd7`:

```
 [title "Correct move order: Nd7 before c4, actually setting up Nd3"]
 [fen "r2qrbk1/1b3pp1/p2p1n1p/1ppP4/Pn2P3/5N1P/1P1N1PP1/RBBQR1K1 b - - 0 16"]
 [startflipped "0"]

 1...Nd7 {black entertains both options of f5 and c4 after Nd7} 2. Ra3 {These are nuanced moves which were specially polished in Kasparov-Karpov games of 90's. Ra3 is a multi-faceted move, moving the rook to a protected square so that axb5 axb5 lines do not force white to exchange rooks at once, moreover activates the rook along the 3rd row both additional coverage of d3 square and potential rook swings to kingside} c4 3. axb5 axb5 4. Nd4 Rxa3 5. bxa3 Nd3 {black appears to be losing a pawn nonetheless, however as demonstrated by Morozevich among others, black is in fact able to maintain the awkwardly advanced d3 pawn with Nc5 which gives black sufficient dynamic compensation for the pawn} 6. Bxd3 cxd3 7. Re3 Nc5 {and black is well on time with Nc5 as opposed to what transpired in the game where black delayed Nd7 to after c4!} 8. Nxb5 {not white's best choice} (8. Bb2 {white's best choice here is not to take the pawn as that gives black too much counter-play.}) Qa5 9. Nd4 Qc3 {and Qa1 threats are constantly in the air. Additionally, the knight on d2 is bound to the defense of the e4 pawn. Black is clearly better.}

```

It would go beyond the scope of this post to exhaust all possible sub variations both with and without `Nd7`, however I hope the above discussion and lines clarify the importance of the inclusion of `Nd7` (and the playability of the ensuing lines) in contrast to the inaccurate early `c4` without `Nd7` as happened in the game.

# Answer
> 4 votes
We can only imagine that he somehow had a human moment, and messed up.

The normal move instead of 16...c4 is 16...Nd7 17.Ra3 and only then 17...c4.

The way it was played, it was almost the forced loss of a pawn. He had the option of Qb6, but it left him with a miserable position anyway.

```
 [FEN "r2qrbk1/1b3pp1/p2p1n1p/1ppP4/Pn2P3/5N1P/1P1N1PP1/RBBQR1K1 b - - 0 1"]

1... c4?  (1... Nd7 {Preparing f5 immediately so that the Nb4 can come back to d5 after any trade of pawns.} 2. Ra3 c4 3. axb5 axb5 4. Nd4 Qb6 {And black is doing well.}) 2. Nd4 (2. Nf1 {The computer thinks this is even better since the Nb2 is susceptible to Bd2 forcing Nd3 which will lead to the loss of a pawn.}) 2... Qb6 3. N2f3 bxa4 (3... g6 4. Be3 {And this is very uncomfortable for black due to the weakness on b5, and the unfortunate queen.}) 4. Rxa4 a5 {And black's queenside is wrecked.}

```

---
Tags: opening, positional-play, ruy-lopez
---


# Question
Title: During the 1984-1985 Karpov-Kasparov match, what was Karpov's initial weight?
When discussing whether chess is a sport, I have often used that Karpov lost a reported 22 pounds (10 kg.) during the match as a point to show that chess can be physical. While 22 pounds is significant, I think it is even more significant because Karpov was a man with a very slight stature, meaning it was a much higher percentage of his total weight than if he had been a 250-pound man, but nowhere have I ever been able to find what his initial weight was.

Does anyone know Karpov's initial weight at the start of that match, or even his final weight, which would also tell us that information?

Here is one such story.

# Answer
> 5 votes
That's a lot, if validated. Karpov was rather slight at the time, something around 60kg or less, so that represents something under 20% of his body weight.

And actually, that's consistent with other facts, given that was a 50+ game match. Fabiano Caruana says he can drop around 10% of his body weight during a difficult tournament. (Said to an ESPN reporter.) Robert Sapolsky, a Stanford researcher, has measured some players at burning 6000 calories per day in a tournament.

Another unverified data point is Rustam Kasimdzhanov losing 17 pounds at the 2004 championship.

A lot was made of this recently, made "sexy" because Magnus Carlson sought the advice of Olympic trainers for his physical conditioning, but it's not a new discovery. Petrosian would also drop a lot of weight during the championship match cycle, and other champions like Botvinnik and Spassky made getting in physical condition an important part of their match preparation.

ESPN, NPR ("The Chess Grandmaster's Diet"), Men's Health, seems like every magazine got in on it last year.

I don't have anything verifiable on the Karpov bit, but the other work I've seen, taken with the comment from Caruana, means I'll accept it as true until someone can disprove it. It's been verified to happen to players other than Karpov, so why not him?

---
Tags: kasparov, karpov, match
---


title: Tactics in Firouzja's game round 3

text:
# Question
Title: Tactics in Firouzja's game round 3
In round 3, Firouzja and Artemiev played a very interesting Caro-Kann game, with white constantly trying to open up the position even at the cost of pawns, in order to exploit black's exposed king position, which indeed proved to be decisive and white won.

It seems that in these Caro-Kann structures, white has to be really careful not to lose the center pawns with some combinations. For example in the game, after white castled, I noticed that although at first glance it seems the `e5` pawn can be won after `Nxg3, fxg3, Nxe5` using the pin, but white has the `Na4` intermezzo first dislocating the queen then winning the knight on `e5.` Here it is diagrammed:

```
 [title "e5 not really hanging"]
 [fen "r3kb1r/pp1n1pp1/1qp1p1b1/4PnBp/2BP3P/2N3N1/PP3PP1/2RQ1RK1 b kq - 2 12"]
 [startflipped "0"]

 1...Nxg3 2. fxg3 Nxe5 3. Na4 Qc7 4. dxe5

```

This one I could figure out. But what I don't get is, instead of going after the `e5` pawn, after castling, couldn't black have won the `d4` pawn which is doubled attacked by the knight on `f5` and the queen on `b6`, while only being defended once with the queen:

```
 [title "why didn't black take on d4 here?"]
 [fen "r3kb1r/pp1n1pp1/1qp1p1b1/4PnBp/2BP3P/2N3N1/PP3PP1/2RQ1RK1 b kq - 2 12"]
 [startflipped "0"]

 1...Qxd4

```
* Why couldn't black take on `d4?` Is it simply because after `Qxd4 Qxd4 Nxd4` white has sufficient positional compensation considering all the pieces are actively posted and black's still behind in development? or are there simply direct tactics preventing `Qxd4` altogether?

# Answer
Good job on the first tactic: indeed `e5` is not really hanging in that line due to `Na4.`

As for the `d4` pawn, although even in the line you suggest (with the exchange of queens) white stands a tad better, the `d4` pawn is in fact **tactically defended!** Considering that you do not mention any computer evaluations and have tried to tackle the problem on your own (which is excellent!), I reckon you're more interested in not just seeing the solution but to also see how to get there, so let's walk through it together.

To recognise the combination, take note of black's weakpoints around the king:

* king stuck in the center,
* the dark the square holes around black's king,
* the bishop taking away the `e7-d8` squares, and the potential of a smothered type of mate were the knight to land on `c7`,
* the open `d`-file (thanks to `Qxd4`) and the fact that the `d7` knight is only defended once by the king (therefore vulnerable to direct tactics).

With these in mind, now try to find forcing moves (captures, checks, threats of mate or gain of material, etc.) that exploit these weaknesses and see if you can make them work concretely.

The first move that comes to mind, challenging all the aforementioned weaknesses at once, is `Nb5,` with the double threat of attacking the queen and mating on `c7.` Rather interestingly, `Nb5` works out beautifully: if black doesn't capture on `b5`, then they lose on the spot due to dark square weaknesses. And if they do capture the knight, then they end up further opening the position (as `cxb5-Bxb5` open the critical `a4-e8` diagonal towards the king) and lose due to the compromised king position and lack of defenders (in turn caused by lack of development).

Let's see how all this pans out concretely: (*no time to cross check the lines with a computer, I leave that up to you!*)

```
 [title "Lines after 12...Qxd4"]
 [fen "r3kb1r/pp1n1pp1/1qp1p1b1/4PnBp/2BP3P/2N3N1/PP3PP1/2RQ1RK1 b kq - 2 12"]
 [startflipped "0"]

 1...Qxd4 2. Nb5 cxb5 (2...Qxd1 3. Nc7#) (2...Qb6 3. Nxf5 exf5 {loses on the spot as it allows e6 opening the e-file} (3...Bxf5 4. Nd6+ Bxd6 5. Bxe6 {A real blow to black's position! Note Qxd6 at once doesn't work due to Qc5} fxe6 (5...Bxe6 6. Qxd6 {now Qxd6 works as the c5 square is guarded by the rook on c1}) 6. Qxd6 {only way to avoid mate without losing the queen is to make a run for it via f7} Kf7 7. Qxd7+ Kg8 {and white's clearly winning thanks to the domination of the bishop and queen, e.g. after Rcd1 Kh7 Qf7 wins the e6 pawn}) 4. e6 Nf6 5. exf7+ Bxf7 6. Re1+ Ne4 7. Nd6+ Bxd6 8. Qxd6 {and black has to sacrifice their queen to avoid mate}) 3. Bxb5 a6 (3...Qxd1 4. Rfxd1 f6 5. exf6 gxf6 6. Rxd7 a6 {threatening to win the rook after Ba4 b5} 7. Ne4 {Nf6 threatened with mate} Be7 8. Rxe7+ Kxe7 9. Bxf6+ Kf7 10. Rc7+ Kf8 11. Bxh8 axb5 12. a3 {and white's completely winning, being up a healthy pawn, better piece coordination, while black's king remains exposed and the 3 isolated pawn islands are useless offering no prospect of counter-play.}) 4. Qxd4 Nxd4 5. Bxd7+ Kxd7 6. Rfd1 f6 7. Rxd4+ Ke8 8. exf6 gxf6 9. Bxf6 Rh7 10. Re1 Rc7 {baiting white to take on e6 with Rxe6+ Kf7 and white's rook defending the bishop will be easily overloaded} 11. Bg5 {calmly side-stepping the double attack with Kf7} Bf7 12. Ne4 {and white's advantage is once again decisive: clear pawn up, all 4 pieces perfectly coordinated against black's king stuck in the center, meanwhile all of black pieces are bound defensively, and both the e6 and h5 pawns are extremely weak and will fall soon with slow technical play.}

```

**What a beautiful tactical adventure! This makes for excellent practice of both tactics and calculations.**

It's worth noting that in some of the lines discussed above, black is not necessarily getting checkmated or even being necessarily a piece down, instead, the position becomes heavily damaged and black ends up at least a clear pawn down, all of which is more than enough of an edge to win considering the caliber of players we are talking about.

Finally, Artemiev need not necessarily have calculated all the above lines to realise `d4` is not in fact hanging. Instead and particularly for players of such strength, they either have seen it before in a game or in preparation, or based on their strong intuition they simply smell the overwhelming dangers that could arise if they went pawn hunting with their king stuck in the center.

Last but not least, calculating very forcing lines (such as the above) is in fact the easiest type of calculations due to their inherent nature of being *forcing* (their branch outs are limited and the remaining lines are very concrete thus requiring less positional judgement). Meaning that e.g., performing all the above calculations over the board is quite feasible for strong players, and somewhat even trivial for super GMs.
> 6 votes

---
Tags: tactics, middlegame, caro-kann
---


title: Equation for Handicap

text:
# Question
Title: Equation for Handicap
Are there any sort of equations for how much of a handicap one should receive to make a game between two players with differing Elo ratings as balanced as possible?

There might be a time equation to determine how much more time one player should receive in relation to the other. Or, an equation to determine how many more points one player should be up in relation to the other at the start of the game. Or, an equation that factors in both a time and point handicap. (When I refer to points, I am not referring to Elo. Rather, I am referring to point difference given from an engine analysis.)

If there's some way to translate point difference towards probability of winning then making a point handicap equation should be fairly easy, since one can figure out the probability of winning given the Elos of the players.

(I realize there are questions similar to this question. I have seen those questions, and they were not asking for the specifics that I am asking for.)

# Answer
> 5 votes
> Are there any sort of equations for how much of a handicap one should receive to make a game between two players with differing Elo ratings as balanced as possible?

The short answer is "No", there is no scientific equation, but it doesn't stop people from trying.

For instance, our club runs an annual handicap tournament in which it tries to produce a practical answer to this question. The rules for the tournament are here.

> Players are first put into numbered bands according to their grading with the highest graded players in band 1 and lower graded players in bands 2 and upwards. Then the handicap when two players meet is determined from the following table according to the difference between the players’ bands.
>
> 0 – no handicap, first named player in the draw has white
> 1 – colour, player in the higher band number has white
> 2 – 2 moves, player in the higher band number has white and makes two moves instead of one to start the game
> 3 – f pawn and move, player in the higher band number has white, remove f7 pawn
> 4 – f pawn and 2 moves, remove f7 pawn, player in the higher band number has white and makes two moves instead of one to start the game
> 5 – knight, remove b1 knight, player in the lower band number has white
> 6 – rook, remove a1 rook, player in the lower band number has white
> 7 – queen, remove d1 queen, player in the lower band number has white
> 8 – queen and knight, remove b1 knight, remove d1 queen, player in the lower band number has white
> 9 – queen and rook, remove a1 rook, remove d1 queen, player in the lower band number has white

Basically if the rating difference is less than 100 then the players are in the same band, a band difference of 1 equates to a 100 to 199 rating point difference, 2 band = 200 - 299 difference, 3 band = 300 - 399 difference, etc.

In recent years the winner's rating has varied between about 1500 and 2000 so it doesn't seem to favour any particular level although from experience I would say with large handicaps there is a definite skill for each player in adjusting how they play in terms of risk-taking.

---
Tags: analysis, rating, elo, handicapping, handicap
---


# Question
Title: What is black’s compensation in the main line of the Caro Kann?
After move 10 in the main line of Caro Kann, black has already moved its light-squared bishop four times, while white manages to develop quite a bit.

What exactly is blacks compensation for the lack of development?

```
[fen ""]
[Startply "21"]

1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 Nd7 8. h5 Bh7 9. Bd3 Bxd3 10. Qxd3

```

# Answer
> 22 votes
At a basic level, what we want from an opening and a defense, is: we want to be fighting for the center squares **(1)**, we're trying to develop our pieces and get good squares for them **(2)**, and thirdly, we want to have a safe king **(3)**. This is as modest a expectation as one can have for a *good* opening.

Now roughly speaking, there are two types of defenses (say e.g. against 1.e4): First type: we attack the pawn on `e4`, like the Scandinavian, the French, and the Caro-Kann,..., in other words, any defense where we immediately set out to immediately attack the pawn on `e4` is the *first* type of defense. The second type of defense is to leave the `e4` pawn alone and basically, black's saying I'll go and take my fair share of the center, typical example is the Sicilian (`1...c5` first dark-square claim).

In diagram you've posted, we see a typical Caro-Kann structure where black's trumps are:

* we have successfully managed to exchange one of white's central pawns (`e4`), which was the primary goal of our defense.
* There's definite prospect for challenging white's 2nd central pawn (`d4`) with a timely `c5` or `e5` advance in the middlegame. And the `d5` square is a nice post for a knight.
* In case white aims for `c4` to control `d5,` then `d4` being in a semi-open file, becomes a bit of a soft spot which black can target, and the extra expansion on the queenside by white means their queenside castling is less likely or at least less safe.

So it's fair to say expectation **(1)** is ticked off. **Now onto (2)**:

* Black is clearly behind in development: white has 5 developed pieces (pawns and nonpawns), black has 3, moreover, white's ready to castle kingside and 1 tempo away from queenside castling whereas black's kingside castle is at least 3 tempi away.
* However, thanks to our successful neutralisation of the `e4` pawn, the central struggle has quieted down, and our path to finishing development is rather clear (and resolved for the most part), namely: `e6-Nf6-Be7-O-O.`
* It's not just that we are finishing development, but we are in fact achieving decent piece activity: most importantly, the knight on `f6` which plays both a very important defensive role for the king, and provides good central control. The `d5` square could in certain cases be a good outpost for either the knight or even sometimes the queen. In case of the former, then `f6` square becomes free for our `d7` knight to jump to.
* The knight on `d7` is not poorly placed as it is ideally placed to eye both `c5` and `e5`, the two pawn advances black will be aiming for next in order to challenge white's `d4` pawn (dark-square control).
* Same holds for the bishop, which more importantly, is not hemmed-in inside our own structure.

These points tick off expectation **(2)**. **Now onto (3)**:

* As said, we have no trouble in castling kingside, where the king will be well protected by our minor pieces (knight on `f6`, bishop `e7` and knight on `d7` which can go to `f8` if need be).
* Thanks to white's over-advancement of the `h` pawn all the way to `h5`, their prospect of exploiting our hook `h6` on the kingside is not so easy anymore. Ideally, to exploit the `h6` advance when pushing against the king, is to have the `h4-g4` setup. All to say, tempo-wise, white is sufficiently away from amassing a major threat on our kingside.
* Last but not least, white has no means of decoying our minor piece defense on the kingside, and the somewhat weakened light squares are less of a concern since the respective bishops have been traded off.

These points all suggest that we have in fact a solid structure and our kingside castling remains safe, so **(3)** is ticked off as well.

---

In conclusion, we have seen why the structures that emerge from Caro-Kann (in particular for the posted variation) are solid and more importantly, we see that black's opening has successfully achieved our 3 basic expectations, so we can give ourselves a tap on the back and claim to have played a successful defense.

Extra bonus aspects about the position:

* The queen can easily swing over to the queenside `b6` or `a5` and create threats, in general you want to be inducing additional pawn advances from white on the queenside to make it more difficult for them to castle safely on the queenside. So manoeuvres like `Qa5` and `Qb6` are much needed!
* The `d`-file is semi-open for black, which gives us a pressure point and rook activity.
* The `c5` advance (and sometimes `e5`) should be a part of your middlegame strategy in order to neutralise white's remaining central pawn and dark square control.
* The `h5` pawn can sometimes be a real weakness, that you can easily target.
* A queenside expansion is almost always perfectly valid.
* Last but not least, I highly encourage you to study Caro-Kann games for inspiration. For example, look into the games of Vassily Ivanchuk, Jovanka Houska, Yasser Seirawan or Aleksandra Goryachkina, who've produced many instructive Caro-Kann games.

# Answer
> 10 votes
The main reasons it is OK for black is that he is still down only one tempo in piece development, but he has traded off his bad bishop for white's good bishop, and his position is still very solid so he will catch up in development eventually. The downside is that white has more space. Black can eventually fight back with c5 after finishing his development, which is the key to the opening from black's perspective.

I have played the Caro for decades, and it is very solid, but you have to be very patient, and well-prepared, or it is easy to get rolled over due to white's space.

Here are a few examples from the highest level. The first, is black successfully hitting back with c5, breaking up the white center. The second and third are Kasparov showing how white can successfully use the kingside pawns (I am posting these primarily to show that my comment below about h5 not really being weak is accurate).

```
 [Event "Corsica Masters 5th"]
 [Site "Bastia"]
 [Date "2001.10.30"]
 [Round "2.2"]
 [White "Leko, Peter"]
 [Black "Anand, Viswanathan"]
 [Result "1/2-1/2"]
 [ECO "B19"]
 [WhiteElo "2739"]
 [BlackElo "2770"]
 [FEN ""]

 1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 Nd7 8. h5 Bh7 9. Bd3 Bxd3 10. Qxd3 e6 11. Bf4 Bb4+ 12. c3 Be7 13. O-O-O Ngf6 14. Kb1 O-O 15. Ne5 c5! {breaking up white's center} 16. Ne4 cxd4 17. Qxd4 Nb6 18. Nxf6+ Bxf6 19. Qe4 Qe7 20. Ng4 Rfd8 21. Nxf6+ Qxf6 22. Be3 Rxd1+ 23. Rxd1 Nd5 24. Bd4 Qf4 25. Qxf4 Nxf4 26. g4 b5 27. Kc2 Nd5 28. Kb3 a6 29. a4 f6 30. Ra1 Rb8 31. axb5 axb5 32. Ra7 e5 33. Rd7 exd4 34. Rxd5 dxc3 35. bxc3 g6 36. hxg6 Kg7 37. Kb4 Kxg6 38. Rxb5 Re8 39. c4 Re4 40. f3 Rf4 41. Rd5 Kf7 42. Rd3 f5 43. gxf5 h5 44. Kb5 h4 45. c5 Rxf5 46. f4 Rh5 47. Rh3 Ke6 48. Kb6 Rh6 49. c6 Kd5 50. Rd3+ Ke4 51. Rh3 Kxf4 52. Kb7 1/2-1/2

```

The next game shows the structure I mentioned in the comment below. Kasparov did not actually break through on the kingside, but he used the cramping threats on the kingside to eventually attack the queenside! Anand might have been able to draw in a couple of places, but that is no easy feat against the great Kasparov. A beautiful rook ending by Kasparov.

```
 [Event "Linares 20th"]
 [Site "Linares"]
 [Date "2003.03.01"]
 [Round "7"]
 [White "Kasparov, Garry"]
 [Black "Anand, Viswanathan"]
 [Result "1-0"]
 [ECO "B19"]
 [WhiteElo "2847"]
 [BlackElo "2753"]
 [FEN ""]

 1. e4 c6 2. d4 d5 3. Nd2 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 Nd7 8. h5 Bh7 9. Bd3 Bxd3 10. Qxd3 Ngf6 11. Bf4 e6 12. O-O-O Be7 13. Kb1 O-O 14. Ne4 Nxe4 15. Qxe4 Nf6 16. Qe2 Qd5 17. Ne5 Qe4 18. Qxe4 Nxe4 19. Rhe1 Nf6 20. g4 Rfd8 21. Be3 Bd6 22. f3 Rac8 23. c4 a5 24. a4 Nd7 25. Bd2 Bc7 26. Bc3 Nxe5 27. dxe5 c5 28. Kc2 Rxd1 29. Kxd1 Rd8+ 30. Ke2 Rd7 31. f4 Bd8 32. f5 Bg5 33. f6 b6 34. Ra1 Rd8 35. Ra3 gxf6 36. Rb3 Bf4 37. Rxb6 Bxe5 38. Bxe5 fxe5 39. Rb5 Rd4 40. Rxc5 Rxg4 41. b3 Rg3 42. Rxe5 Rxb3 43. Rxa5 f5 44. Ra8+ Kg7 45. c5 Rc3 46. Rc8 Ra3 47. c6 Rxa4 48. Re8 Rc4 49. Rxe6 f4 50. Rg6+ Kh7 51. Kd3 Rc5 52. Kd4 Rc1 53. Ke4 Rc4+ 54. Kd5 Rc3 55. Kd4 Rc1 56. Ke4 Rc4+ 57. Kf3 Kh8 58. Rxh6+ Kg7 59. Rd6 Kh7 60. Kg4 Kg7 61. Rd7+ Kf6 62. c7 1-0

```

Lastly, here is a game that made an big impression on me when I first read Kasparov's notes to in in his book, "The Test of Time". How he used the kingside pawns was amazing, and his final move shows how dangerous they are. I will use a few of Kasparov's own annotations for the demonstrative points about the pawn play.

```
 [Event "EU Team-ch07 Final"]
 [Site "Skara"]
 [Date "1980.01.26"]
 [Round "7.8"]
 [White "Kasparov, Garry"]
 [Black "Vukic, Milan"]
 [Result "1-0"]
 [ECO "B19"]
 [WhiteElo "2595"]
 [BlackElo "2460"]
 [FEN ""]

 1. e4 c6 2. d4 d5 3. Nd2 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 Nd7 8. h5 Bh7 9. Bd3 Bxd3 10. Qxd3 e6 11. Bd2 Qc7 12. O-O-O Ngf6 13. Ne4 O-O-O 14. g3 Nxe4 15. Qxe4 Be7 16. Kb1 Rhe8 17. Qe2 Bd6 18. Rhe1 Re7 19. c4 c5 20. Bc3 Nf6 21. Ne5 cxd4 22. Rxd4 Bxe5 23. Rxd8+ Qxd8 24. Bxe5 Rd7 25. Bc3 Qb6 26. g4 Qd6 27. f3 a6 28. a4 Qd3+ 29. Kc1 Kc7 30. Qxd3 Rxd3 31. Rf1 Kc6 32. Kc2 Rd7 33. a5! {+- "the ending, in my opinion, is lost for Black - he is markedly cramped, and the balance of forces remaining on the board is the ideal one for White." - Kasparov} Ne8 34. Re1 Rd6 35. f4 Nf6? {"One can understand Vukic aiming to prevent g4-g5, after which the sacrifice at g7 becomes a possibility in various lines, e .g. 35...Kd7 3 6 g5 Rc6 37 Rdl + Kc8 38 BXg7! But, engaged in a difficult defence, the Yugoslav grandmaster forgot for an instant about the defects of his pawn structure and the unfortunate position of his rook at d6. The retribution followed immediately."} 36. Bxf6 gxf6 37. Rd1 {"Black resigns, since in the pawn ending White creates passed pawns on both flanks."} (37. Rd1 Rxd1 38. Kxd1 Kc5 39. g5 fxg5 40. fxg5 hxg5 41. h6 {wins}) 1-0

```

This final position, and the ability to create a passed pawn on the king side, combined with the pawn move f6 in the second game to do the same (after gf ef and later g5) is why this structure is very strong for white.

# Answer
> 0 votes
solidity (c6+e6 pawn structure is hard to break down)

h5 pawn can be weak in endgame.

White can have king safety issues if black castles kingside and plays b5 (black has king safety issues too there :) )

---
Tags: opening, caro-kann, development
---


# Question
Title: Is it bad form to go for a lengthy but losing endgame that you suspect will be winning on time?
In blitz games, I sometimes have to choose between sharper positions that I suspect will put me at some slight positional advantage and positions easily played by my side but difficult for my opponent which, if they play correctly, they should win.

For example, I might have the option to exchange down to a queen versus rook endgame where I have a 1-minute time advantage or go for a rook and bishop versus rook endgame where I have the extra bishop but where I might have to use up a lot of time to get there. Given that choice it seems to me that holding a rook versus queen endgame is relatively easy if my opponent is under time pressure (assuming the endgame is not easily converted into the Philidor position) but winning the bishop endgame is less certain.

That said, when I start sacrificing material for no real advantage except to temporarily solve my opponent's most recent attack, it seems to me that my opponent is likely to get irritated that I am trying just to win on time. I'm not sure what the appropriate etiquette is in such situations regarding play, however.

# Answer
> 17 votes
All is fair in love, war, and blitz (at least with regards to winning on time, and short of outright cheating).

In blitz, time is a major factor in the game, and it is fine to try and win on time in any situation.

If you used too much time, and your opponent thinks he can flag you, there is nothing wrong with that. It is part of the game.

I have seen Grandmasters check with a queen right next to the opposing king that can be taken for free to win on time, just because it requires that split second to realize what happened.

P.S. If someone does not like being flagged, they can always play with an increment.

# Answer
> 7 votes
There is nothing wrong with winning on time. You just have to understand the risk losing game by position. In a competition time is also the factor. To avoid brutal play on time Fisher and similar time controls where invented, but if your competition uses old style controls without increment is totally fine to win on time, especially a blitz game. Managing ones time is required skill of tournament player.

---
Tags: endgame, etiquette, blitz
---


# Question
Title: Why is 1. Nf3 not nearly as popular as 1.e4 and 1.d4?
The opening move 1. Nf3 is considered as a perfectly sound opening and it is popular, but not nearly as popular as 1.e4 and 1.d4. Here are my thoughts about this:

1. In most openings, white will make the move Nf3 sooner or later. Since white needs this move (in most cases) anyway, why not make it the first move?
2. White has much flexibility with 1. Nf3. Here are a few examples:

For 1. Nf3 Nf6, white may reply with either 2.c4, transferring to the English or 2.d4, transferring to Queen's Pawn Game.

For 1. Nf3 d5, white may continue with 2.d4, transferring to Queen's Pawn Game.

For 1. Nf3 c5, white may reply with either 2.c4, transferring to the English or 2.e4, transferring to Sicilian.

At the same time, white is not afraid of some weird replies such as 1. Nf3 e5 as replying this with 2. e4 is perfectly fine for white. Capturing the pawn may be fine for white as well.

---

Why then is 1.Nf3 not nearly as popular as 1.e4 and 1.d4?

# Answer
> 11 votes
It is funny since 1.Nf3 scores better than any other opening move per Mega 2020 at 55.5% winning percentage for white, compared to only 52.8% for 1.e4, 54.3% for 1.d4, and 54.4% for 1.c4.

I think a lot of it is psychological regarding the types of positions that can arise. 1.Nf3 is the most fluid of all the moves I mentioned, and I think that players simply like more concrete play than not. It also reduces what you need to memorize, or understand, if you go straight into a specific pawn formation with d4, e4, or c4.

I also think that at the lower levels, that fluidity can lead to positions that players, both players, but since it is white's choice, that he/she specifically is not as comfortable with since he/she can end up on his/her own in a hurry. You need to know A LOT more about transpositions into other openings, which is a major undertaking. The play is also more complicated, which drives weaker players away more.

At the upper levels, meaning 2700s, I do not believe that they are afraid of getting lost in the opening as easily, but there still may be an underlying desire to play "their" openings, so they play more concretely.

One thing I do not believe is that after 1.Nf3 that 1...e5 is a valid response. White, having played 1.Nf3 probably likes d4/c4 openings, so is not likely to go into a double-king-pawn opening, but still has a great response:

```
 [FEN ""]

 1. Nf3 e5? 2. Nxe5!

```

Thanks for the gumball, Mickey! (from an old U.S. commercial for a Mickey Mouse gumball machine)

Based on my discussion with Phonon below, I am adding this chart that shows the flexibility of each main opening move that aims for the closed openings (d4/c4/Nf3). At the higher levels, this is a main reason, but at lower levels, I still believe that it is more about psychology, and believing that immediate occupation of the center is crucial. At lower levels this also can often put your opponent on unfamiliar grounds,

# Answer
> 7 votes
Questions of this nature seem to have become a reoccurring theme recently here on chess SE, but that's a good thing because understanding basic opening ideas is understanding fundamentals of chess strategy. So let's tackle the question from this angle, in an attempt to objectively relate the merit of first moves for white to their popularity.

Why `1.e4,` `1.d4,` `1.Nf3` etc, for such questions it helps to think at the most basic and fundamental level. Before comparing these first move candidates, we need a few notions:

*(In the scope of this post, brevity and basics are of essence. Thus, the discussed concepts should be taken with a grain of salt when applied to high level chess, where decision making in the opening is an entirely different matter, partly due to the extremely high level of targeted preparation).*

---

In chess, to establish an edge as the side that makes the first move of the game, you need to be dictating roughly the flow of the game, which means playing a greater role than your opponent in the type of positions that may emerge from the opening. On the one hand, this means the particular set of pawn skeletons that can arise, and on the other hand, what choices are you taking away from your opponent. In other words, you should try to impose your own agenda and prevent your opponent's as much as possible.

## Territory and central squares:

Now, what is it that we want from an opening to begin with? Briefly, we want to have a fair share of the center, to have effectively posted minor pieces (both defensively and offensively), and a safe king (number one priority). Most relevant for your question, is the fight over central squares, so let's limit our discussions mostly to that. To clarify the used concepts and terminology, consider the following diagram:

The **red** rectangles show each side's **territory**. The **green** rectangle highlights the **16 central squares**, and the **4 blue-highlighted squares** inside it show the **sweet center**, i.e., the 4 most important squares on the board.

Let's now go a tad deeper into what is meant by *fight over the central squares,* and establish some sort of rough baseline:

* We want to be controlling as much of the 16 central squares as possible, and most importantly the 4 sweet central squares `e4,d4,e5` and `d5.`
* Think of pawns as space creators: the pawn backbone is really what defines the mobility and effectiveness of your other pieces.
* The ideal scenario of *controlling the center* is: to have our own pawns centrally established in the center (`e4,d4`) and have our opponent's respective central pawns traded for our own non-central pawns (like black typically does in the Sicilian, trading their `c7` pawn for white's `d2`, which in itself is a favourable trade for black since the more central a pawn is, the higher its relative value).
* Now of course this is the ideal, and as such we never fully get there, nonetheless it is what we're ultimately fighting towards.
* Next comes: what makes pawns established in the sweet center so good? In short, pawns in the center provide space and support for our knights to be posted centrally (thus most effective) and while also making it more difficult for our opponent to achieve the same ideal minor piece posts.
* Moreover, the 4 central squares maximise your options of rerouting pieces between the two flanks, from the centre an attack on either flank can be backed, and pieces have a higher relative value when centralised: because not only do they acquire their maximum mobility (max number of moves) but they also secure space both in both camps.

---

## Basic comparison of first moves:

With these kinds of ideas in mind, let's now compare the 3 first moves `1.e4`, `1.d4` and `1.Nf3` and do the tally:

## `1.e4`

* Occupies **one** square (`e4`) in the sweet center, provides control over **two central** squares (`d5,f5`) in our opponent's camp, while activating **two** of our pieces (a kingside bishop and our queen)

## `1.d4`

* Similarly, occupies **one** square (`d4`) in the sweet center, provides control over **two central** (dark) squares, while activating again **two** pieces (a queenside bishop and our queen). Compared to `e4`, the queen activity is less relevant (as `d2,d3` squares are not really useful queen squares) and the bishop is not a kingside one, which matters a tad less than kingside bishop, since kingside development is to be priotorised in order to establish a safe king as fast as possible, and before committing to any attack. But all in all, it's still as good as `e4` in terms of the central space it provides.

## `1.Nf3`

* Occupies **zero** squares in the sweet center (only eyes `d4`), provides control over only **one** of our opponent's central squares (`e5`), while activating **no** other piece with the spent tempo. So clearly, it's not as cost efficient as our two previous options in terms of how we're investing our extra tempo. Naturally then, as a first move, it gives plenty of choices to our opponent for the type of structures they could aim for, which means a portion of our edge as white being first to dictate the game has been given away.

In diagrams:

---

Thus, with these comparisons made purely at a very basic level, it stands to reason that `1.e4` or `1.d4` ought to be white's best investments of the extra tempo and explain their popularity. Anything else would be forfeiting some part of our advantage as white one way or the other. But bear in mind, we're talking at the core and most basic possible level, meaning, these ideas alone don't translate into whose winning or losing. In actuality of real games, things are never that simple, and our decisions will depend on many factors including our mood, preferences, opponent's preferences, and so on ....

Sometimes, we just want to get a normal position, and don't really care about that small plus white has early on, then moves such as `1.Nf3` become perfectly valid options. Particularly, when one is trying to avoid heavy theory or simply not walk into the opponent's preparation, then openings such as the English `1.c4` and `1.Nf3` become ever so viable, as they are less committal (and thus less critical) and can still transpose to a wide range of structures.

# Answer
> 6 votes
The first moves 1. Nf3, 1. d4, 1. e4 and 1. c4 are all good. It is a matter of taste which one you prefer, as they usually lead to different types of position. All these moves have their advantages and disadvantages.

After 1. Nf3, you have to consider the black replies 1. ... d5, c5, Nf6 at least. 2. c4 is a fine continuation in all these cases. Of course, you could play c4 first, but then you'd need to be prepared for 1. c4 e5. If you don't like that, that is an advantage of 1. Nf3. On the other hand, you must be willing to play either the Reti (1. Nf3 d5 2. c4), or a different second move in case of 1. ... d5.

You also suggest 2. d4 against 1. ... d5 or Nf6. Of course that move is fine, but after 1. d4 d5, most players don't play 2. Nf3, but 2. c4. If the plan is to enter the London system, Colle, or Torre attack, you could as well play d4 first - there is little black can do to prevent 2. Nf3. Possibly c5 - then you must decide whether you prefer 1. Nf3 c5 or 1. d4 c5.

But of course you don't have to play 2. c4 or 2. d4. Actually the second most popular second move for white after 1. Nf3 is 2. g3, followed by 3. Bg2 and an early 0-0 - the Kings Indian Attack. Often, white plays d3, e4 and Nbd2 later. This is also a solid setup. But it is surely not to everyones taste, and some players prefer to reach it after 1. e4 only after certain black responses (especially against the french).

So much for the value of 1. Nf3, you can hopefully see that it takes some options from both you and your opponent, while allowing others, and you must decide which ones you want to allow or prevent.

Regarding the option to enter an open sicilian: don't overestimate that. There is a lot of theory to learn in that opening, only to meet the third most common option black has on his second move. I'd consider this an option against certain opponents only. In general, this kind of flexibility isn't worth much. Instead of having the possibility to transpose into multiple openings, it is better to concentrate on fewer openings which you really know - at least as an amateur. (If you want to surprise your opponent, "really know" can include side lines you can enter on a later move)

---
Tags: opening, theory, reti-opening, space
---


title: Minimax check(mate) detection

text:
# Question
Title: Minimax check(mate) detection
in my minimax function I have a first few lines looking something like this:

```
children = board.get_all_possible_moves(board)

if depth = 0 or board.is_check_mate or board.is_draw:
    return None, evaluation(board)

```

The problem is that it takes time to calculate the children one "extra time" if the depth is 0 and the position is not draw or check mate. However, I want to know if the board state at depth 0 is check mate or draw.

As of now I detect check mate and draw by the following logic:

```
if not possible_moves:
    if board.is_check:
        board.is_check_mate = True
    else:
        board.is_draw = True

```

Is there a better way of finding whether a posisiton is check mate or not? Without having to calculate the opponents possible moves first, to save time in the minimax recursive function.

# Answer
Your approach is correct. Stockfish does it as well.

> https://github.com/official-stockfish/Stockfish/blob/master/src/search.cpp

```
if (rootMoves.empty())
{
  rootMoves.emplace_back(MOVE_NONE);
  sync_cout << "info depth 0 score "
            << UCI::value(rootPos.checkers() ? -VALUE_MATE : VALUE_DRAW)
            << sync_endl;
 }

```

There shouldn't be much penalty in performance, because:

1. You will always need to generate candidate moves anyway
2. Your code should maintain a bitboard (or other data structure) for the pieces checking the king. You will always need this information in your evaluation.

Consequently, what you're doing is just checking information that you already have.
> 3 votes

---
Tags: engines, check, minimax
---


title: When is castling possible?

text:
# Question
Title: When is castling possible?
Is castling possible if any of the squares involved in the castling are under attack, or is this a problem only if the squares moved through by the king are under attack and not the ones moved through by the rook?

# Answer
> 54 votes
Yes, if the rook is threatened, you may still castle. The threatened squares rule only applies to squares where the king passes (starting and final position included).

For example, in the case of white castling queenside, for instance, a threat to `a1` or `b1` does not prevent the castle from taking place.

# Answer
> 82 votes
Yes, you can, as long as the king doesn't pass through or end up on an attacked square.

From FIDE Laws of Chess:

> **3.8.2.1** The right to castle has been lost:
> *3.8.2.1.1* if the king has already moved, or
> *3.8.2.1.2* with a rook that has already moved.
>
> **3.8.2.2** Castling is prevented temporarily:
> *3.8.2.2.1* if the square on which the king stands, or the square which it must cross, or the square which it is to occupy, is attacked by one or more of the opponent's pieces, or
> *3.8.2.2.2* if there is any piece between the king and the rook with which castling is to be effected.

# Answer
> 31 votes
One nice example of this is in this game, where a player named Feuer takes advantage of the ability to castle queenside while b1 is attacked to play a beautiful combination.

```
[FEN ""]
[Event "Belgian Championship"]
[Site "Liege BEL"]
[Date "1934"]
[EventDate "?"]
[Round "?"]
[Result "1-0"]
[White "Otto Feuer"]
[Black "Alberic O'Kelly de Galway"]
[ECO "C73"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "25"]

1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.Bxc6+ bxc6 6.d4 f6 7.Nc3
Rb8 8.Qd3 Ne7 9.Be3 Rxb2 10.dxe5 fxe5 11.Nxe5 dxe5 12.Qxd8+
Kxd8 13.O-O-O+ 1-0

```

# Answer
> 22 votes
The rules are that the king can't castle *into* check, *through* check, or when *in* check. This applies to the king's square, plus the two squares to the right or left.

Castling is permitted when the *rook* is under attack (on the rook's square). On the queen side, that would also include the knight's square. But not on the kingside, because the king would be castling *into* check. He also can't castle if the bishop's or queen's square is under attack.

# Answer
> 7 votes
You can castle when **all** of these conditions hold true:

1. The King and the Rook did not make any moves so far.
2. The King is not in check.
3. The King will not pass a threatened square during castling.
4. The King will not land on a threatened square.

Condition 3 might need clarification. For example, you have the white pieces and you want to castle kingside. Then, you are using your Ke1 and Rh1 for castling. Let's say that conditions 1 and 2 are fulfilled. Next, the g1 square should not be threatened in order to fulfill condition 4. Finally, the King will pass the square f1 on its way to g1. Thus, the square f1 should not be threatened for condition 3 to hold true!

# Answer
> 2 votes
There is more on the condition to consider The King and Rook have to be on the same rank, otherwise Pam-Krabbe castling would be possible. Pam-Krabbe castling is basically a vertical castling, where the king would castle with a promoted pawn. This is not allowed anymore.

# Answer
> 0 votes
Here is a problem that I published in the MatPlus.net forums a few months ago. It demonstrates how the rook can move through squares that are attacked. The squares a1 and b1 are maximally guarded. If it were on a board, it would definitely frustrate a few people, which is the exact point of this little exercise!

```
[Title "me, Matplus.net Forum 5/24/2019, Mate In 2"]
[FEN "8/8/8/8/pppbbp1r/nr2pppB/q2n2Pp/R3K2k w Q - 0 1"]

1. O-O-O+! Nf1 2. Rxf1#

```

---
Tags: rules, kings, castling, rooks, check
---


title: Angle of view of the board

text:
# Question
Title: Angle of view of the board
I noticed that when I play online I play much better than when I play facing a chess board. I suspect this is due to my table being tall so my angle of view isn't the best one.

So I was wondering if the height of the table and chairs are also more or less the same in tournaments. Does it happen to you too?

# Answer
There definitely could be something to this.

My father, and a friend of mine, were air traffic controllers. They both told me that you generally want a smaller screen so you can see everything at once.

The friend was also a chess player, and we talked about how big you wanted the chess app or browser to display the board. It does seem to make sense that if it is smaller, that you can see everything, and thus, not miss something that is in your periphery vision.

I can very easily see that translating to a larger physical board that you see the pieces on an angle, if playing on a computer is your normal way of playing.

Of course, there may, or may not, be studies about this in similar situations; but I figure if the U.S. government trains their people about this, there is probably something to that even if I do not have the source material they base it on.
> 3 votes

# Answer
> I suspect this is due to my table being tall so my angle of view isn't the best one.

Online ratings are usually inflated or higher than over-the-board rating system. I remember I achieved an 2300+ on chessclub.com, but my FIDE is much less. There were GMs over 3200+ on the system, but they were just about 2600 FIDE level.

Are you sure you ***really*** performed stronger online?
> 1 votes

---
Tags: online-chess, board-vision
---


# Question
Title: Is my positional pawn sacrifice justified?
Today I have played a game and the following position was reached:

```
[fen "rn1qk2r/p4ppp/1p2bb2/1Q1pp3/8/3P2P1/PP2PPBP/RN2K1NR b - - 0 1"]

1... Nd7 2. Bxd5 a6 3. Qb3 Nc5 4. Bc6+ Ke7 5.Qa3 Rc8 6. Bg2 Qd6 7. Nd2 e4

```

I quickly thought that covering the check with the knight would hang a pawn, but it seems that there is so much to it. After 10. ...Nd7 11. Bxd5 a6 12. Qb3 Nc5 13. Bc6+ Ke7 14.Qa3 Rc8 15. Bg2 Qd6 16. Nd2 e4, Black is still a pawn down but apparently it is compensation enough for Black.

However, I am unable to see why the pawn sacrifice is justified for a small lead in development which White can finish in at most 2 moves with Nf3 and O-O.

# Answer
> 2 votes
*Word of advice regarding the screenshot of lichess you had posted in the OP: Whenever you're checking with an engine, try to limit the number of best variations to 1-2 lines, as the more variations you choose the more distributed the allocated resources of the engine become and the less accurate the displayed evaluation.*

Black here is clearly better thanks to the dominant central control, the bishop pair (both developed too) and the extra piece white develops for you with their `Qb5+` check. So even before `Bxd5,` as things stand, black has the lead in time (development) and in space. Therefore, white's best bet is to at least try and win a pawn, in order to claim some sort of compensation.

> However, I am unable to see why the pawn sacrifice is justified for a small lead in development which White can finish in at most 2 moves with Nf3 and O-O.

If this was really the case then indeed white would be safely getting away with the snapped pawn, but therein lies the problem: if white plays it correctly, their best bishop retreat option is to `e4` and not `g2`, and although black has lost their castling right they've gained a huge initiative on the kingside starting from `g5` (aimed for `g4`) to boot the knight to a passive square and launch the kingside pawn avalanche. Let's just see some of these variations:

```
 [title "Analysing variations after 11.Bxd5"]
 [fen "r2qk2r/p2n1ppp/1p2bb2/1Q1pp3/8/3P2P1/PP2PPBP/RN2K1NR w KQkq - 2 11"]
 [startflipped "1"]

 1.Bxd5 a6 {our aim is to boot the queen away from the defense of the bishop} 2.Qb3 Nc5 3.Bc6+ {intermezzo check: only move to not lose material immediately} Kf8 {the king is even well placed on f8 as there are literally no foreseeable threats against it.} 4.Qd1 Rc8 5.Bg2 {a poorer choice than Be4, as the continuation shows white will be losing material very quickly if black's e-pawn is not blocked} (5.Be4 {white's best chance, to maintain the position somewhat closed and block the e-pawn} g5 {important positional move, to aim for g4 as quickly as possible exploiting the bishop and knight's awkward placement on e4-f3. With the knight booted away from f3, black is ready to launch an all out attack on the kingside with h5-g4 if white were to castle} 6.Nf3 g4 7.Nfd2 h5 8.O-O h4 {next to our bishops, our rook on h8 is perfectly placed to assist in the attack. The conversion from here is technically simple, and as soon as white retreats with Bg2 we have e4 ready. So there's no easy consolidation for white's king.}) e4 6.Nc3 (6.dxe4 Qxd1+ 7.Kxd1 Bxb2 {wins trivially}) exd3 {white's center and king safety are becoming further comprised, white has 5 active and well posted pieces in an open position against a king stuck in the center.} 7.Nf3 (7.exd3 Nxd3+ 8.Kf1 Bxc3 9.bxc3 Bc4 10.Ne2 Qf6 11.f4 Nxf4 12.gxf4 Qxf4+ 13.Ke1 Re8 14.Bf1 Qf3 15.Rg1 Qxc3+ 16.Kf2 Qe3+ 17.Kg2 Bxe2 {and the win is trivial from here.}) dxe2 8.Qxd8+ Rxd8 9.Kxe2 Bc4+ 10.Ke1 Nd3+ {and black wins trivially as further loss of material is unavoidable thanks to the comprised king position}

```

So you see, black is comfortably cashing in their lead in development and space in all the variations ensuing from `Bxd5,` and converting them into winning positions. And in most cases, the moves sort of play themselves considering how natural black's initiative and attack are as we saw in the diagram. Thus, all in all, we consistently come to the conclusion that the pawn sacrifice starting from `Nd7` is perfectly sound. I encourage you to practice playing these lines and the ones we haven't considered yet against the computer.

# Answer
> 2 votes
My Stockfish on a fairly strong computer found your exact line as best also, but I am going to continue it out a little.

You wrote: "I am unable to see why the pawn sacrifice is justified for a small lead in development", but the reality is that you have a HUGE lead in development since the immediate threat is Nd3 ed Qa3 and Bxa1, and other moves allow black to increase his attack with tempo. This is a common thing in positions with a development lead, and it important to factor in when looking at a development lead...it is not enough just to count moves to catch up in many positions. Also, with e4!, black is going to rip open the game before white can finish developing and react. This is a good principle to understand...strike hard and early when you have a significant development lead. Quiet play will let the opponent catch up.

Black is not just better...black is won here.

```
 [FEN ""]
 1. g3 d5 2. d3 e5 3. Bg2 Nf6 4. Bg5 Be7 5. Bxf6 Bxf6 6. c3 Be6 7. Qb3 b6 8. c4 c6 9. cxd5 cxd5 10. Qb5+ Qd7 (10... Nd7! 11. Bxd5 a6 12. Qb3 Nc5 13. Bc6+ Ke7 14. Qa3 Rc8 15. Bg2 Qd6 16. Nd2 e4! {opening the position before white can finish developing} 17. Rb1 (17. dxe4 Nxe4 18. Qxd6+ (18. Qe3 Qxd2+ 19. Qxd2 Nxd2 20. Kxd2 Rhd8+ 21. Ke3 Bxb2) 18... Nxd6 19. Ngf3 Bxb2 20. Rd1 (20. Rb1 Bxa2 $1 21. Rxb2 Rc1#) 20... Bxa2) (17. Nxe4 $4 Nxe4 18. dxe4 Qxa3 19. bxa3 Bxa1) 17... exd3 18. e3 b5 19. Ngf3 Rhd8 {With two bishops, a pawn on d3 that is super annoying, and the Qa3 is quite uncomfortable, this is just won for black.}) 11. Qxd7+ Nxd7 12. Nd2 Rc8 13. Nh3 O-O 14. O-O g5 15. f4 gxf4 16. gxf4 Kh8 17. f5 1-0

```

---
Tags: tactics, positional-play, sacrifice
---


# Question
Title: How to combine Basic Strategies to a winning-system
Suppose one want to have a strategy so one can win over a "normal/average" chess-player. I was thinking that there was a set of strategies which could be combined so that one could memorize it? Say the opening and the middle game. Then one could always win over a "non experienced" chess-player.

# Answer
That's not how chess works.

Chess has too many possibilities for a "one size fits all"-strategy or set of strategies that you could learn by heart.

At the risk of repeating myself: Learning chess is like learning a language. It's kind of hard to learn a set of sentences that allow you to win any debate against an average debater.

Instead, "understanding" is the key. Languages and chess have to be learnt the hard way: Maybe some rote learning can be beneficial, but mostly you'll need lots of practice and exposure to "good chess"/correct language until you have developed an intuition about sentence structures/connotations/positions/tactics etc.
> 6 votes

# Answer
Here is a knockout strategy that works, if you do all these things:

1. Move your pieces off the back row as soon as practical. Try to move at least one knight and one bishop before moving the queen, however.
2. Per #1, don't move the same piece twice in the beginning of the game without a good reason.
3. Castle as soon as you can.
4. Occupy the center of the board with your pawns and pieces. The center of the board allows you to attack either side, and constricts your opponent.
5. If you can take your opponent's pieces, do so. Material superiority is helpful. Be careful about traps, however.
6. After you choose your move, use your mind to visualize the board as it will be in the next move or two. If you don't like what you "see", choose a different move.
> 2 votes

# Answer
It depends on what you call average/normal and just how good you are.

The only strategy guaranteed to work is just to keep making better moves than they do.

If you are at all decent then you should be able to beat a non experienced player just by playing well.

You should be more concerned about what a very experienced or very good player is going to do to you.

I would say what you need more than a magic strategy is to study the basics of tactics, end games, pawn structure, and learn one opening well.
> 1 votes

---
Tags: chess-variants, online-chess
---


# Question
Title: Who did Kasparov call a talented amateur?
I heard that Kasparov called some strong player a talented amateur? Who was that? Thanks.

# Answer
I will answer in the first line of the next paragraph, but there is a lot of history that happened right around the time Kasparov made this comment, so I will add in some of that too.

At the Tilburg tournament in November 1997, Kasparov was not known for holding his tongue, and he called Grandmaster Shirov, who was 2700 and 8th in the world, a "talented amateur". Shirov did not appreciate the remark. Kasparov’s comment is ironic since it was only about a year later that Shirov would upset Kramnik in a match (5.5-3.5) to win the right to play Kasparov for the PCA (Professional Chess Association) World Championship in 1998, but the match never took place because there was no sponsor since Intel, and later Linares organizer Luis Rentero, pulled out, and the money could not be secured. The PCA collapsed. Shirov was probably not without blame as it is alleged that he refused to play since his cut was too small.

My opinion is that if you are not champion, you should play, and if you win, then you have more leverage…get paid big down the line. That said, it is a big stretch to think that Shirov would have beaten Kasparov anyway as Shirov was Kasparov’s “customer”, meaning that Kasparov beat him like a drum throughout their career. The lifetime record was 16 wins, 15 draws, and zero losses for Kasparov.

After this happened, a new sponsor, BrainGames.com, was eventually secured for a Kasparov match, but unfortunately, the sponsor tried to sign Anand to play Kasparov, but this fell through too. Shirov was naturally upset that he was not signed, and called Anand a “pickpocket”, and he felt that Kasparov had to play him before he played any other matches. It turned out that since even that match never took place, Kasparov ultimately played Kramnik in 2000, and well, we know how that turned out: Kramink, a heavy underdog, used the Berlin Defense to the Ruy Lopez, and won by a score of 8 1/2–6 ½. Anand would go on to win the separate FIDE World Championship knockout event that year as Kasparov had previously broken away with the classical title in 1986.
> 12 votes

---
Tags: history, kasparov
---


# Question
Title: What should I do about the dilemma of castling early?
OK, it has been said that one of the opening fundamentals is to castle early, but I have a dilemma with this and it may very well be a natural dilemma that has to be dealt with or there may be signs that one could look for. Here is the dilemma:

If I castle early, I feel my opponent has a slight advantage especially because now they know where to direct their pieces, but if I delay castling and my opponent moves their pieces to the one side of the board and I castle on the opposite, I feel I have gained some time because they have to work their way back to my castled side, however, I do know that if I do not castle early, I risk leaving my king wide open. Further light on this would be helpful.

# Answer
I think you outline the balance well, that is what it is. You are talking about attempting to misdirect an opponent. In any game, misdirection is a dangerous tactic that takes skill to know when to make your move.

If you can get to know your opponent you can try to judge how they will move on you. If you are dead set on castling to a particular side, and your opponent knows that, then delaying doesn't help you at all.

The best solution is to remain flexible and let your opponents over or under steps dictate which tactic to use. This is as true for when to castle as anything other tactic.
> 17 votes

# Answer
The answer is twofold - learn your opening theory, and learn how to defend.

If you can defend yourself against the attack, then you're not "castling into the attack", you're simply castling. Of course, you could be wrong, and castling could be a mistake, but that's chess - you have to make trade-offs, trust your instincts, and calculate the position.

In most openings, opening theory tells us whether the risk/reward trade-off of castling on a given side of the board is worth it. You never see white castling queenside in the Grunfeld, and that's because we know from opening theory that it's too risky. An advanced study of the French and Sicilian defenses helps a player gain a better intuition for when it is and is not okay to castle kingside.

Sometimes, of course, we don't even know, and castling is a gamble. In the Sicilian and Caro-Kann defenses, black often castles kingside without being sure whether or not it's a suicide move, and hopes that his counterplay and defensive abilities are stronger than his opponent's attacking abilities.

There really is no way to say "in positions with these features, you can castle, and in positions with these features, you can't" unless you're a computer playing computers. Learn opening theory so you can get a good intuition for when it is and is not okay to castle (If you think it might be, it probably is) and then become a better defender so you can defend yourself against whatever attacks your opponents may choose to throw at you. Unless you're playing Houdini or Kasparov, your opponent is unlikely to execute his or her attack perfectly, and it is a test of skill rather than a positional decision.

Of course, sometimes it's really obvious that you shouldn't castle, like when you have a totally fractured kingside. But categorizing such positions would be pointless because what matters is context. Similarly, if all your opponent's pieces are on the kingside, that's also a sign that you shouldn't castle there. You have to have faith in your defensive abilities, though, otherwise you'll find yourself being afraid to castle just because your opponent played `1. h4`.
> 19 votes

# Answer
The idea is not to castle early or late. The idea is to castle when it supports the *rest of your strategy*.

In some games, you want to emphasize quick development, especially if your opponent has lost time. In that case, early castling is a feature of that development.

On the other hand, if it's a game with emphasis on maneuvering, you may want to delay castling until your maneuvers are complete (or nearly so), in order to use castling to support your maneuvers.
> 12 votes

# Answer
Here I'll provide you a good example of castling too "early". In the Pirc Defense, Black will usually get roasted in the line

```
[fen ""]
1. e4 d6 2. d4 g6 3. Nc3 Bg7 4. Be3 Nf6 5. Qd2 O-O?!

```

In this line White has not castled yet, and with the queen-bishop battery can just swap off bishops by playing `Bh6`, followed by `f3`, `g4`, `h4-h5` to ditch the h-pawn and then play `Qf6+`, etc. with a tremendous attack.

But, the point to remember in general is not to castle into an attack for no good reason or compensation.
> 8 votes

# Answer
This is from the perspective of "concrete" chess:

In modern chess, there is no hard or fast rule, it all boils down to calculation and prep. As world champion Anand has demonstrated in his match against Kramnik: this and this (just two games later, and again with Black!), *it is the results that matter*. So don't worry about castling early or late, but whether you are finding the strongest moves and are satisfied that you have worked out the tactics that are befitting your playing level.
> 6 votes

# Answer
If you are an inexperienced player (\<1900) you should castle quickly. Yes, you may get crushed occasionally by a stronger player but you probably will lose those games anyway.

Players above 2000 can get away with leaving their kings in the center (usually)because they understand the types of positions they can get away with it in and can see the attacks coming several moves ahead.

I have a very aggressive style and I can guarantee I'm far more likely to win against inexperienced players if they don't castle. In fact, a large part of my rep is devoted to preventing the opponent from castling. I will sac pawns in a heartbeat and often pieces to keep the king in the center. That should tell you something.
> 3 votes

# Answer
The purpose of castling is to protect your king. Yet, the opponent can wait with castling to see which side you will castle and then launch a pawn assault on that flank. This is possible, because the opponent can later castle on the opposite side. These types of positions are known as "positions with opposite castling" and they have a special place in terms of middlegame strategy. My advice would be for you to wait for your opponent to castle and then castle on the opposite side and launch a pawn assault on the opponent's king. Practice these types of positions and learn about them by examining grandmaster games and studying books on the topic. Another strategy is to castle queenside as quickly as possible and then control the center as well as possible with pawns and light pieces. If the opponent castles queenside too, then you just play as normal. If the opponent castles kingside, launch a pawn assault (g and h pawns) and try to open the g-file or h-file for your rooks.
> 1 votes

# Answer
What dilemma? You castle because there are NO other moves that are pressing.

You castle because you have a need to unite your rooks and/or put you king in a safer location.

You castle because it is the best move in that position.

You do not castle to put a check in some box on a list.

Your opponent has been putting his pieces on the best squares, not moving them to one side expecting you to castle there.

You know you can put your pieces in front of your king too, right?

Most games are not won by an attack on the king. They are won by the total position leading to material and a won endgame.
> 0 votes

---
Tags: opening, theory, castling
---


# Question
Title: How do you deal with you losing your concentration
How do you do deal, with losing your concentration during a chess match? Then making a bad blunder? I constantly lose concentration.

# Answer
> 6 votes
I started writing this before your comment that it is online chess. My answer is geared more toward over-the-board tournament chess. I will add a little blurb specifically about online chess at the bottom, but a lot of this applies to both.

There is a lot to your question. Primarily how you deal with it comes down to experience and practice. The unfortunate part is that everyone gets that experience all too often. The initial key to not getting into that situation as often is to try to stay calm and relaxed when you play, and use your time wisely, and do not get into deep time trouble.

The first question is how bad is the error? If it is bad enough that you lose the game, you have to just put it behind you, and prepare mentally for the next game. I find that while I take the game seriously, because it is not my profession, I do not take it too seriously, and therefore, I can put it behind me easily. Do not beat yourself up over something that you can no longer control.

If it is a mistake during the game, and not so bad that you lose, that is different. It is important to mention that sometimes you will make a losing mistake that is not obvious to your opponent, but you see it. It is important to keep an absolute poker face so you do not clue your opponent in that there is something there. When you make that type of error that you have to get in the habit of buckling down and trying that much harder at the board until the end of the game. Staying as positive as possible is important.

Other ways you can cut down on such “accidents” are making sure that you sleep and eat well. I would be careful of eating a lot of carbohydrates, or you might go into a fog that I call a “carb coma”. I also think that reading short exciting games without a board, but absolutely keeping the position in your head, will help your concentration before you even sit down at the board.

For online chess, you will lose games…a lot of games, but they really do not matter much, so put it behind you, and click rematch, and move on to the next game.

In the end, practice, practice, practice. Good luck!

# Answer
> 1 votes
First and most important is Your physical form.

That's where most opinions on chess and good chess players are wrong - all top chess players take care of their physical form - very popular are swimming, tennis, table-tennis, football(soccer for Americans).

Also you have to sleep well, enough but not too much. Don't eat too much before game - also makes you sleepy. In classic game stand-up and have a walk every now and then to make blood circulate.

Being fit helps you to keep concentration.

---
Tags: tactics, psychology
---


title: How to install chess.pgn on python?

text:
# Question
Title: How to install chess.pgn on python?
I don't know how to import chess.pgn on Python. I searched everywhere, but I didn't find anything. Can anybody here help me?

# Answer
If you've already installed python-chess via pip/conda/choco or your favourite package manager, then to use chess.pgn, in your .py files just call `from chess import pgn` or `import chess.pgn`. You have to explicitly write either import, even if you already have `import chess`.

Then you can use it like

```
from chess import pgn

with open("my_pgn_file.pgn", "r") as pf:
    game = pgn.read_game(pf)

```

If I had used `import chess.pgn` instead, then I call it by changing the last line to `game = chess.pgn.read_game(pf)`.
> 2 votes

# Answer
First you need to install this library:

```
pip install python-chess

```

And make sure you're using the right `pip`, because still in some Linus distros `pip` and `python` are `python 2.x` and for `python 3.x` you should use `pip3` and `python3`. If you want to check try this:

```
pip --version

```

You will see an output like this that will tell you what python you're using, in my case it's 3.8:

> pip 19.2.3 from /usr/lib/python3.8/site-packages/pip (python 3.8)
> 4 votes

---
Tags: software, pgn, python
---


title: About castling “fights”

text:
# Question
Title: About castling “fights”
Today I played as White in an interesting bullet game in which a strange “fight” occurred.

```
[FEN ""]

1. d4 e6 2. Nf3 b6 3. e4 Bb7 4. Bd3 g6 5. Be3 Bg7 6. Nc3 Qe7 7. Qd2 Nc6 8. a3 a5 9. h3 h5 10. Qe2 Bh6 11. Bxh6 Nxh6 12. Qe3 Nb8 13. e5 Ng8 14. Qd2 d6 15. exd6 cxd6 16. Qe3 Nf6 17. Ne4 Ba6 18. Bxa6 Nxa6 19. Nxf6+ Qxf6 20. Qd3 Nc7 21. Qe3 Kd7 22. Nd2 Rae8 23. Nb3 Nd5 24. Qd3 e5 25. O-O-O Nf4 26. Qf3 Qg5 27. dxe5 Rxe5 28. g3 Ne2+ 29. Kb1

```

During the game, it seemed, to me at he least, that were playing out a “fight” of who would castle first. In my thoughts, it is advantageous to castle on the same side as the other side, so we tried to make each other castle first to know each others intentions. In other words, it was a drawn out tempo play revolving around who would castle first. This fight lasted in my game until Black played 21... Kd7.

My question is not about my game, but about this concept of such a castling fight. What should be done if you find yourself in one? Are their any strageties for these situations? Finally, have there been any top level games where a, preferably somewhat extended, castling fight occurred?

# Answer
You may have been in a fight or not. Top players do not fight that way they make the moves best for their position. Sometimes they delay castling but not to fight the opponent.

This seems to be a tactic used by weaker players who might want to mount an attack on the other king. The position should decide whether that is the best strategy or not.

Not sure why you two did it that way as there had to be better moves available. it looks more like you all were struggling to just make moves so did what you did. So being a bullet game might explain some of the moves that I would not have considered.

That said I would have just moved the white king up earlier and not castled at all as there is no danger of an attack and it would ensure that my king has an endgame advantage should black castle. I note that is what black did to white later.

But then I would have made a number of different moves earlier on that would have changed the entire game making the question moot:)
> 3 votes

# Answer
I'd question whether its "advantageous" to castle on the same side as your opponent. Often it's safer, but that's not always the case and even so "safer" does not mean "advantageous." Remember, when you castle on the same side as your opponent, that means they've also castled on the same side as you; it can't be "advantageous" for both of you at the same time. Any advantage you have has to lay elsewhere; advantages come from imbalances, not similarities.

Most of the top players know which side their opponent is going to castle on within the first half-dozen or so moves, because the castling choice is indicated by the characteristics of the position on the board. It's very rarely that a player pushes their g-pawn one step forward and *doesn't* castle king-side, for example.

The position itself will tell you where it's advantageous to castle. Black will only rarely castle Queen-side in the Stonewall Dutch or the Sicilian Dragon, no matter where White castles. It just doesn't make positional sense to castle anywhere but king-side in those kind of positions.

My answer, as you might guess, is "Don't find yourself in one." If you intentionally delay castling, you delay completing your development because you can't connect your rooks until you've castled. An advantage often lies in being the first to complete your development, meaning being the last to castle may often work against you, not for you.
> 2 votes

# Answer
Let's ignore the whole "fight" aspect for now and consider why we castle in the first place. The key advantage of castling is that you 1) bring your rook to the center, and (more importantly) 2) get your king to safety. Exceptions apply of course, but usually, you're looking to castle on the side where the opponent isn't going to attack.

The other thing to remember is that the opponent's king is usually going to be behind a wall of pawns. If you're going to launch an attack, you'll want to advance your pawns to break apart that pawn shield. Of course, the opponent is also thinking the same thing.

The position of your king influences these plans. Consider your game position after 21. Qe3. If Black plays 21...O-O, then 22. O-O-O intending Rdg1, h4, g4 etc becomes a legitimate plan for you. This doesn't mean it's a good plan - Black can also play Rfc8, Rab8 and b5-b4 etc - but it's a legitimate option. Similarly if Black plays 21...O-O-O, then 22. O-O followed by a queenside pawn advance becomes a legitimate plan for you.

What if, after 21...O-O, you decide to play 22. O-O? Then neither player will be attacking on the kingside (advancing your king's pawn shield is not a good idea unless the opponent absolutely cannot mount an attack on your king). The game's battleground moves to the queenside and it'll take on a strategic theme where direct attacks don't happen. The same goes if you meet 21...O-O-O with 22. O-O-O.

Therefore choosing which side both players castle into changes the strategic character of the game, and accordingly the available plans. You'll want to consider these before deciding where to castle. For example, in your specific game, you could decide that 21. O-O is a fine move because if Black plays 21...O-O-O and attempts to attack your king, your queenside counterplay will be faster (I'd bet on it; Black's queenside has vulnerable squares plus you have a pawn majority on that wing).
> 1 votes

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Tags: strategy, castling, master-games
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# Question
Title: Why isn’t Black forced to prevent e4 in this Queen’s Indian Game?
Today, I played this game in which I played the Queen’s Indian Defense. This position was reached:

I played Be7, which is a correct move. I wonder however, why Black isn’t forced to play Bb7 in order to prevent e4? If White wants to, after exchanging on f6, they can play e4.

Compare it to my recently question regarding the move d5 by White in a Pirc Defense:

When is preventing e4 no longer a priority for Black?

In the Pirc Defense I even possessed a pawn in the 5th file which means I still had certain control over the center and yet in the Indian where I had no control of the center with advanced central pawns, e4 can be allowed. Why?

# Answer
> 4 votes
There is a huge difference here, and that is first, that you will get the bishop pair for white's big center, but also that your Bf6 is beautifully placed for they typical black move in the Queen's Indian, c5, which will cut across the a1-h8 diagonal. Also, the white center can be successfully attacked.

In the other example from the other question, cxd4 does not break up the center at all, and there was still the danger to the black king with e4-e5. You can see that in your game today, e4-e5 allows the queens to be traded, and will actually leave e5 vulnerable.

```
 [FEN ""]

 1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. Bg5 Be7 5. Nc3 (5. Bxf6 $6 Bxf6 6. e4 d6 7. Nc3 Bb7 8. Be2 c5 {Breaking up the center or if d5, making the Bf6 a monster.} 9. d5 Qe7 10. O-O O-O 11. Re1 Nd7 12. Qc2 Ne5 {And black is very comfortable.}) 5... d5 6. e3 Bb7 7. Be2 Nbd7 8. O-O dxc4 9. Bxc4 O-O 10. Ne5 Nxe5 11. dxe5 Ne4 12. Bxe7 Qxe7 13. Nxe4 Bxe4

```

By the way, while Be7 is not technically wrong, it is not in the spirit of that opening, and is a bit passive. Here is a typical line fighting for, and keeping control of e4.

```
 [FEN ""]

 1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. Bg5 Bb7 5. Nc3 Bb4 6. e3 h6 7. Bh4 g5 8. Bg3 Ne4 9. Qc2 Bxc3+ 10. bxc3 d6 11. Bd3 f5

```

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Tags: opening, analysis, queens-indian
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# Question
Title: How strong is each level of Atari 2600's Video Chess?
I used to play Video Chess on Atari with my dad when I was a kid. What is the approximate FIDE rating of each level?

# Answer
> 2 votes
Atari 2600 has bugs which make the higher levels unrateable. It is reputed to be slightly better than Microchess, according to a chess.com article.

Atari had a very limited book which makes it weaker than current approaches.

An ESTIMATE of the strength is as follows:

Level Time Rating(?):

8 10 700

1 15 800

2 30 1000

3 45 1100

4 165 1300

5 195 1350

6 720 ??

7 36000 ??

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Tags: rating, computer-chess
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# Question
Title: How many games to get a good idea of computer chess board rating?
I have an old Radio Shack 1850 Electronic Chess Computer, which I would like to know the ELO rating each level plays at. The instructions just give average number of seconds per move.

I figure I would play it against tChess Pro on my iPad, which the engine can be set to a specific ELO rating. When I find they are both winning about the same number of games I can check what level tChess is at and that will be about what the 1850's rating is.

Question is, how many games would be a good sample before I make that call? Obviously if one dominates the other, I'll have to tweak the levels and retry.

# Answer
> 3 votes
There is no perfect answer here. First, and it is for a reason, FIDE says that you need 9 games to have an established rating, but the USCF says you need 25. Obviously, the more games, the closer the rating will be to accurate. That said, to really get a more accurate rating, you also need to vary the competition, and have it play against various rated humans.

I think that it is probably too weak to pair up against any modern computer program that is rated. It would get slaughtered, and not help you determine how strong it really is.

I would say at least 10.

# Answer
> 0 votes
Statistically , based on comments from my stat prof at the uni, I would say it would take at least 5 games but in practice that might easily be ten or 100 depending on many exogenous factors.

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Tags: engines, computer-chess
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