# Question
Title: Strategy for next move in a crowded situation
White is in the presumably better position in the situation below. However, under such conditions (e.g. there are tight formations of many pieces on the board), I find it usually hard to 'breach' the opponent's defense, i.e. to capitalize the advantage.

For example, I tend to favor c4 as the next move and subsequently trying to capture/exchange pieces in order to clear the way to the king.

The question here is what the direction of white's next moves should be?

```

[FEN "2k1rbnr/ppp5/1q4p1/3pNp1p/1P1P4/B1P1P1P1/P3Q2P/1KR1R3 w Kk - 0 1"]

```

# Answer
The position you are having here is also quiet though I guess. You can ask yourself first: What do I want to play for? Then you can analyse the position as the following: 1.) Black has some kind of weakness in the g6 pawn, how can I attack that? 2.) The rook is placed good for opening the c-file, how do I achieve that? 3.) What are the ideas for black in the position?

Then you can search for answers for those questions. 1.) There is no direct way to attack that, but 1. h4 would fix the pawn structure for the moment, therefore it would fix the weakness. Nevertheless, after 1... Bg7 your knight is not very stable on e5, so you probably have to move it away and there is no real way of keeping the pressure on g6, therefor the plan to go for the weakness doesn't really appeal to me. 2.) If you want to play c4 and you want to sidestep Bxb4, a5 ideas, 1. Ka1 could be a smart move. If you assume for a moment that you have to moves in a row, 1.Ka1 2. c4 would allow 2... Bxb4 but after 3. c5 Qa5 4. Bxb4 Qxb4 5. c6 you would have some initative. 3.) Black has several plans, like kicking the knight away from e5 with Bg7, placing the own knight on e4, making pressure on e3. However, placing the knight on e4 is not easy yet since Nf6 allows Nxg6. Therefore black needs to kick the knight away with Bg7 or Bd6 (the latter one allows c4 with threatening c5).

Now you can think of what happens if black tries any of them after 1. Ka1/h4 like 1... Bg7 2. Nd3 and so on, seeing which option seems to be the best objectively and so on improve your position.
> 3 votes

# Answer
Is white better here? Stockfish, Lc0 or another engine may well say white is better, but black has many trumps despite being behind in development.

* The white king position is weak and can be attacked with a5.
* The white knight on e5 looks excellent and puts pressure on g6 but can be eliminated with an exchange sacrifice, followed by Bb2.
* Black's knight on g8 can quickly get to e4 in 2 moves
* Black's rook on the h-file can easily activate with h4

As white, I would be looking to secure my king position with Bb2 and a3, which will support the c4 push at a later time if possible. Right now, the king position is very weak, and it might not be wise to willingly weaken it anymore.

I would also be looking to put pressure on the d5 pawn to tie down black's pieces or induce c6. Black does have a dark-squared bishop to cover that weak diagonal, however, the pawn on c6 is possibly a target.

I prefer the black position here in a practical game without looking at a chess engine evaluation.
> 1 votes

---
Tags: analysis
---


title: I need help Identifying this chess set

text:
# Question
Title: I need help Identifying this chess set
I need help identifying this chess set, I got it from my father and he says it is from Poland and on the broken board it says it is made of crystal bohemia.

# Answer
The closest one that I have found is called celestial strains at: http://www.chess-museum.com/stone--glass-sets.html

There are some Polish sets on the site but they are not the same.
> 2 votes

---
Tags: chess-set, identify-this
---


# Question
Title: Losing the queen and then winning the game
Many years ago, I was on a mountain with some people. I was very young then, between 15 and 17 years old, I think. Some older people came and one of them started to play chess with me.

I cannot recall all the details, but at one moment in the game he captured my queen and I continued to play without it. Besides being without queen, he might have had 1 or 2 of my pawns and a bishop. I also had 1 or 2 his pawns, along with 1 or 2 of his bishops.

Then I started to play very smartly, and, somehow, I manged to capture his queen with a trap made by using rooks and knights. I won the game after that.

Obviously, this is not a question about the particular game I played on the mountain. It is more about, if someone loses his queen at the beginning of the game, what are the tactics to trap and capture the other player's queen?

And also, what is the actual strength of a queen? For example, is it generally better to be without queen or without two knights and a rook but with a queen?

I would like to know more about tactics when some player lost some important pieces, but played so well that he won the game. Are there any tricks that can be used here? I am also interested in such a game in which one player loses their queen, but the other one still has theirs.

# Answer
> 20 votes
Losing a queen early on without any compensation or counterplay means almost certain defeat against anybody except for absolute beginners.

There is a certain "point system" which can be used to evaluate a position:

Basically you assign points to certain aspects of the position, like *material*, *piece activity*, *king safety*, *space advantage*, etc. Adding all those points (with weights depending on the aspects), you come up with a final number, for instance -2. The sign (-) means black is better and the number 2 means that all other things being equal, black could be up by 2 pawns. Of course it could also mean that material is equal and black has much more active pieces, etc.

Just for the material aspect the points assigned to the pieces is usually pawn: 1, knight/bishop: 3, rook: 5, queen: 9 (see this for details) or thereabout.

While this point system is used by computers, for practical play it is not really relevant. I don't know any decent player who would start adding numbers to assess a position.

Still you can use it to answer your question...

Looking at games of top players, within an evaluation of roughly -1 to + 1, i.e. at most a pawn up (all other things being equal), the game usually ends in a draw.

Around +-2, the game would usually be lost/won at GM/IM level, though people might still fight for a while depending on the position.

Around +-3, good players would typically resign immediately.

Of course there are exceptions to this rule and particularly in very tactical/wild positions with open kings and attacking potentials, there could be chances for the losing side.

Still it could give you an idea of what losing a queen (value 9) means...

---

> I would like to know more about tactics when some player lost some important pieces, but played so well that he won the game. Are there any tricks that can be used here? I

The word you mean is "strategy" not "tactics". As outlined above, most people would resign in a situation like you describe. Still, if you think your opponent is weak enough to continue fighting there are a few things you can do to increase your chances:

* keep many pieces on the board (don't exchange pieces): this increases the potential for tactics
* keep the position complicated: typically this means open positions with lots of piece activity
* start a direct attack on the enemy king
* if time is limited try to force your opponent getting low on time, e.g. by moving quickly, doing unusual moves, etc.
* play for tricks/tactics (you really should never do this in chess because it is not how you play chess beyond a certain level...)

# Answer
> 7 votes
Unless there is a clear chance for counterplay, losing your queen means losing the game. You won that game because your opponent was a very bad player.

With regards to the strength of the queen, there is no definite answer, as every position is different. However, as a general guideline:

* Two rooks are slightly more powerful than a queen.
* A rook and a minor piece(bishop/knight) is slightly weaker than a queen.
* Two minor pieces vs a queen often means a lost position.
* Three minor pieces are also slightly stronger than a queen

Some folks will come with a "points system", well, that's just plain wrong.

Finally, queens are a very bad piece at blocking enemy advancing pawns, so that may be a source of counterplay in "otherwise worse" positions.

**NOTE** Since my statement about the pointing system was received with controversy in the comments, let me elaborate a bit further (even though this is beyond the scope of the original question, it's still related and interesting):

* Any scoring system you can think of will always be inaccurate, because we cannot define a total order relation in the "set of piece tandems" that actually models the "is more likely to be stronger than" relation. Even if we could, it wouldn't work well with addition/subtraction (R+6P - N+8P is more likely a rook-side win, but R vs N+2P is more likely to be a knight-side win)
* Piece strength can vary a lot from one position to another, so, even if it were possible to define such scoring system, it would overlook a lot of exceptions and, more importantly, it would give us no criterion about when those exceptions happen.
* Finally, a "one-point advantage" grows in importance as the game gets simplified, so we don't get a good reference either about how well/badly the game is going for us (even if we only care about material)

For those reasons, I think every score-system is wrong (not even entering the discussion of which one would be right, since different people have had different opinions). But all of that does not really matter that much, even if we ignore 1 and 3, the second issue would still be there, and it's quite an important one! It you learn to think in terms of a scoring system, you will eventually have to un-learn all of that and, from my own experience, I can tell you that's really hard! The main problem is therefore that the scoring system is not useful in practice! It does not provide any help in your game and it makes progress more difficult.

@user1583209 pointed out that computers use the points system quite succesfully. Well, that's simply not the full story! Computer position evaluation has worked very differently for a long time, and even if it were the case, there is pretty much nothing to learn from computers in terms of "how to think" as a human

# Answer
> 7 votes
Play the board, not the pieces. Chess is more than just a game of material advantage--much like war. This is why piece sacrifices exist.

Take for example the following game:

```

[FEN ""]
[White "Fabiano Caruana (2823)"]
[Black "Hikaru Nakamura (2779)"]

    1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 { Caruana had not expected Nakamura to play the Najdorf. } 6. Bg5 e6 7. f4 h6 8. Bh4 Qb6 9. a3 { Note b2 is a poisoned pawn and trap for black queen. } 9... Be7 (9... Qxb2 10. Na4) 10. Bf2 10... Qc7 11. Qf3 Nbd7 12. O-O-O b5 13. g4 { Notice either push of pawns is easily met with resistance from end pawns. } 13... g5 { Push of g pawn threatens f pawn with potential setup for knight on e5 (see variation). } 14. h4 (14. fxg5 Ne5) 14... gxf4 15. Be2 b4 { Interesting sacrifice of b pawn. } 16. axb4 Ne5 17. Qxf4 Nexg4 { A second sacrifice for black to that will do well for him. } 18. Bxg4 e5 { With this fork, three of white's pieces are threatened. } 19. Qxf6 Bxf6 20. Nd5 Qd8 { More precise is knight to c6 (see variation). } 21. Nf5 (21. Nc6) 21... Rb8 { Nakamura spent 35 minutes analyzing the position and decided on Rb8, preventing white's threat of Bb6. } 22. Nxf6+ Qxf6 23. Rxd6 Be6 24. Rhd1 O-O 25. h5 { White prepares for Bh4. } 25... Qg5+ { In an effort to stall/prevent Bh4. } 26. Be3 Qf6 27. Nxh6+ Kh8 { As we will see, white will play Nxf7, but could have played it now. } 28. Bf5 Qe7 29. b5 Qe8 30. Nxf7+ Rxf7 31. Rxe6 Qxb5 32. Rh6+ { 1-0 Black resigns. } { Possible continuation: } 32... Kg8 33. Rg1+ Kf8 34. Rh8+ Ke7 35. Rxb8 Qxb8 36. Bc5+ Kd8 37. Rg8+ Kc7 38. Bd6+ Kxd6 39. Rxb8 { White is now up a bishop and two pawns. } 1-0

```

Caruana sac'ed his queen and gained so much space, position, and tempo versus black's side.

Also this game:

```

[FEN ""]
[White "Rashid Gibiatovich Nezhmetdinov"]
[Black "Oleg L Chernikov"]
[Result "1-0"]
[Termination "Normal"]
[ECO "B35"]
[Opening "Sicilian Defense: Accelerated Dragon, Modern Bc4 Variation"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Nc3 Bg7 6. Be3 Nf6 7. Bc4 O-O 8. Bb3 Ng4 9. Qxg4 Nxd4 10. Qh4 Qa5 11. O-O Bf6 12. Qxf6 Ne2+ 13. Nxe2 exf6 14. Nc3 Re8 15. Nd5 Re6 16. Bd4 Kg7 17. Rad1 d6 18. Rd3 Bd7 19. Rf3 Bb5 20. Bc3 Qd8 21. Nxf6 Be2 22. Nxh7+ Kg8 23. Rh3 Re5 24. f4 Bxf1 25. Kxf1 Rc8 26. Bd4 b5 27. Ng5 Rc7 28. Bxf7+ Rxf7 29. Rh8+ Kxh8 30. Nxf7+ Kh7 31. Nxd8 Rxe4 32. Nc6 Rxf4+ 33. Ke2 { 1-0 Black resigns. } 1-0

```

Through shear inundation of threat after threat, Nezhmetdinov creates a formidable attack even apart from his queen.

Chess cannot be simplified to just piece/material advantage. There are more elements at play.

# Answer
> 4 votes
I played a game recently where I lost my queen for a knight early on with no other obvious compensation or counterplay. I almost resigned, but decided to play on for a few moves to see if I could get anything, and ended up winning.

The approach I used was to try and keep pieces on the board, as mentioned in another answer, as any simplification is usually bad if you're down material. Other strategies I used were - to keep attacking their queen; and generally favouring development, coordination, disruption of their position, and piece activity, over material (e.g. not capturing the dark square bishop in the game - link below).

https://lichess.org/zlVS5Nhj

---
Tags: tactics, queens
---


# Question
Title: Is there a binary of Scid vs Mac which works on macOS Mojave?
I had ScidvsMac 4.19 running on my Mac - ScidvsMac-4.19.dmg from https://sourceforge.net/projects/scidvspc/files/mac/ \- but after upgrading to macOS Mojave (10.14.1) it doesn't run - the icon just bounces forever.

I have been trying to use macports compilers to compile the latest source but I am just lost in dependency hell right now because I can't seem to install libgcc7 or libgcc8 properly. I might try to blow everything away and start a fresh install ... but wondering if anyone has overcome these problems?

# Answer
Your question is pretty old. Did you succeeded to resolve your problem? I am running scidvsmac 4.19 on Mojave without any problem. You may download it here:

http://scidvspc.sourceforge.net/#toc3

Best greetings

marek
> 1 votes

# Answer
Since 12 April 2019, Scid Vs PC 4.20 has been available which seems to have fixed the problem for me at least - now works on macOS Mojave 10.14.5.
> 1 votes

# Answer
I'm running ScidvsMac 4.17 with no issues. macOS is Mojave 10.14.2. You may give it a try at: https://sourceforge.net/projects/scidvspc/files/mac/ScidvsMac-4.17.dmg/download
> 0 votes

# Answer
macOS Mojave still supports 32 bit apps. So it should run Scid vs. Mac.
> -1 votes

---
Tags: scid
---


title: How to efficiently memorize games?

text:
# Question
Title: How to efficiently memorize games?
I want to memorize some games so that I can replay them in my mind without a board. The reason for this is that I think it could be helpful for improving my strength. I want to be able to fully replay the game, to visualize the pieces in every position, to check variants etc.

Now this is an arduous task (at least for me).

What do you think is the easiest way to accomplish it?

**Edit:**

This might sound like playing blindfold, but that is not the point of my question. I read about tools for learning playing blindfold, like software to improve visualization-skills or techniques.

I am looking for ideas and hints how I could design the learning process more comfortable when memorizing games – maybe using some kind of software, maybe how to progress when starting to learn a game by heart.

# Answer
> 6 votes
Playing blindfold is not going to be easy, as @Annatar states. Only if you practice much (and accept that you're going to fail the first few times), you will succeed and over time it will probably become easier.

That said, here are some hints:

* **Start with short games.** It's easier to replay a 15 move miniature than a 80 move endgame with lots of rook maneuvers.
* **Use games from openings you play yourself.** If you're not familiar with the Sveshnikov pawn structure or the typical moves of a King's Indian, they'll be harder to remember and to visualize.
* **Use your *own* games.** Especially the most recent one, which is still 'living' in your memory and you probably have analyzed it already after the game itself. Check if you can still 'reach' that position where that crazy bishop sacrifice was possible which you and your opponent talked about in the post-mortem.

# Answer
> 4 votes
I am the author of the software that you might be needing. For example, it is possible to set up an exercise like this https://szachydzieciom.pl/?page\_id=5216&lang=en#6 where the task is to replay blindfold from the score the famous opera game. The score need not be shown, it's just an option. It need not be blindfold, either, it's just an option. I can provide more details if this is the kind of thing that you are looking for.

# Answer
> 2 votes
I basically agree with the points mentioned in Glorfindel's answer (short games in your opening and your own games). A few additonal thoughts:

* IMO there is not much point (for your chess strength) to remember very long games from start to end. I'd limit myself to the opening/middle game and perhaps interesting snippets from the game. What do you gain from remembering say 40 moves in an equalish rook endgame?
* In my experience, as you improve in strength, calculate more deeply and analyze/replay games you will gain the ability to memorize games automatically. You could try to do it the other way around, though personally I'd find it a bit boring to learn (long) games by heart.
* Another idea for learning would be to replay games from notation without a board in your head. Not necessarily with the aim to memorize the game, but to practice visualization.

---
Tags: blindfold-chess, memorization
---


# Question
Title: An objective measure of the difference in strength between top programs and top human players in the four most popular forms of chess?
Is there an objective measure of the superiority (or otherwise) that the strongest computer programs enjoy over the strongest human players which can be compared across the four main forms of chess, namely western chess, xiang qi (Chinese chess), shogi (Japanese chess), and makruk (Thai chess)? For example, can it be said that on comparable Elo scales the programs have say an x point advantage in western chess, a y point one in Chinese chess, and lag behind in the other two games by z points?

# Answer
> 1 votes
I would have to answer no in my opinion. The four forms of chess are different. Shogi from what I remember is a form of chess where capturing an opponent's piece allows you to, at a time of your choosing, put one of that piece on the board as yours. Now that is a level of tactical complexity that surely gives any engine a huge advantage over any strength of human. I have played a little Xiang Qi and I would say the same; in the 90's when Chinese players played Professional western chess for the first time they were awesome tacticians; Xiang Qi as their previous game being very tactical led to that.

# Answer
> 1 votes
While it is *possible* to write engines that can play different chess-family games, doing so generally yields an engine that are only "competent" at each one, at best. The best engines for each individual game incorporate specific knowledge and optimisations for that game, and are usually *incapable* of playing the others.

Many standard chess engines are not even capable of playing Chess960 correctly, because there are special rules for castling due to the variety of starting positions, even though the rest of the game is identical. However, adding this capability does not usually weaken the engine in the way that adding support for Shogi would.

Shogi, in particular, is very difficult to adapt a standard chess-playing engine to play well - even "fairy chess" engines which can support Xiangqi relatively easily. The immediate stumbling block is generally the piece-dropping mechanic, which completely explodes the branching factor of the game tree - so it is very difficult for an engine to explore the game tree to sufficient depth to treat the game in the tactical manner that engines usually do best at. Instead, Shogi has to be treated as a positional game, requiring a sophisticated positional analysis function to determine the correct lines to explore. Human players are naturally better at acquiring this knowledge than computers.

Conversely, a good Shogi engine would need to be taught about the special en passant and castling moves in standard chess, which don't exist in any form in Shogi, as well as the way pawns capture differently from moving, and the way in which pawns can promote to several different pieces rather than just one. All of the specialised Shogi positional knowledge that made it a good Shogi engine would then be useless for playing standard chess.

So the correct approach is to measure any given player's or engine's strength on an individual game. This will generally not be correlated strongly with its strength on a different game, if it is even capable of playing it.

---
Tags: engines, chess-variants, shogi, xiangqi
---


# Question
Title: Can you wait and then perform an en passant capture?
I am new to chess, so sorry for this obvious question. I was surfing through the web and learned the en passant rule. In this question they say "You cannot wait a few moves and then use the en passant capture." So I went searching through websites to find out if I can wait, then play the en passant capture and found nothing. So what I want to know is, if for example there are 2 pawns by each other, can I wait and play a few moves and then perform the move. Example: (I know the image below can't happen, but just saying.)

And then play a few moves like shown below.

And finally capture the white piece using en passant.

# Answer
En-passant can only occur *immediately* after a pawn moves two squares from its starting square, where it could have been captured had it only moved one square.

You cannot wait a move: if you choose not to immediately capture en-passant, you lose the ability to do so next move.
> 7 votes

---
Tags: en-passant
---


# Question
Title: (For training purposes) Are there any openings with rook pawns that are more effective than others (and if so, what are they)?
(Originally I hoped a lengthy prologue would not be needed here, but some of the answers and comments have led me to write one so that the purpose of the question is clear, thus this is now much longer.)

When my child was around six or seven years old, I taught them the rules of the game and basic principles of opening play. At the time, chess didn't seem to hold a lot of interest. However, move forward a few years, and playing with school mates after classes were over led to an interest in the game. Quickly the kid rose above the novices at school and could even beat the teacher. Games between the two of us became competitive, even though I usually - but not always - win. The kid played a few tournaments: in the first 8 the kid had positive records in all but one, which was an open where all opponents were adults with ratings 300 to 500 points better with one exception - an unrated player. There are three trophies on a shelf from these tournaments, including first place from the beginners section of our state scholastic championship. Along the way, we signed up for a year of chess instruction from professional instructors. Also, the kid watches videos online about all aspects of the game and has worked through at least one well respected chess book. It is clear that the kid has a decent understanding of opening principles for someone at this level.

At tournament nine the kid had a bad day. One game in particular stands out: The opposing player opened with 1) a4 ... 2) h4 (or something similar, I don't have the scoresheet). Ultimately, the other kid won the game because my kid didn't know how to respond and got rattled. In some ways this isn't surprising, as any time any person encounters an unusual situation they can get confused and make poor choices.

Don't get me wrong, I certainly want my youngster to learn good chess principles. I don't want to play first moves like a4, h4, a5 or h5, in serious games, nor do I want the kid to do so (at all). However, I've seen other games opened this way by players just learning the game (or using strange openings to confuse their opponents). In order to boost my kid's confidence and provide experience against games like this, I want to (occasionally) play openings at home that may be seen in games at this level. I don't expect to win these games, but that isn't the point: The point is to provide an experience that will benefit the psychological aspects of my kid's game if another player tries a similar opening in the future. Thus, I'm seeking some guidance on strange openings like 1) a4 or 1) h4, that I could at home play against my kid to help prepare for future tournaments.

# Answer
Learning good chess principles and playing against clearly dubious openings like 1. a4 or 1. h4 are not mutually exclusive. In fact, following solid opening principles is the best way to counter weak openings like this.

The moves 1. a4 and 1. h4 are both poor because they do not follow any of the opening principles. Namely, they do not help control the center, they do not develop or prepare to develop any pieces and they actually reduce the king's options as to which side to castle on by weakening the pawn cover on one side of the board.

To counter such a move, you should simply play normal opening moves. 1... e5 or d5 is a good start. If white allows it, you can take over the center by advancing the other central pawn two squares as well. Then simply continue by developing the minor pieces and castling the king to safety. At this point you will have a large lead in development if white has continued making many foolish pawn moves (which is likely against the type of players who open with 1. a4 or 1. h4) and should be able to make life miserable for the opponent.
> 8 votes

# Answer
> Are there any openings with rook pawns that are more effective than others?

There are few recognized openings which start with a rook pawn move on move one, except in circumstances where the opponent starts with a double knight pawn move, because those are generally inferior moves on move one.

One example where it *is* good is if white plays the Sokolski Opening (1. b4). Then 1 ... a5 is a good response.

However they are more common later on in any opening where your opponent fianchettos a bishop because challenging the fianchetto with a rook pawn rush is worth considering if it does not weaken your own position too much.
> 8 votes

# Answer
I'm seeing a lot of great answers being met with, "This doesn't answer my question" - so I'm going to go ahead and answer your literal question (even though the answer won't help you out at all.)

**a4 is the strongest opening rook-pawn move.** In tournament games, it still leaves white with a slight edge to winning (28.9% to 25.8%) which is much smaller than good moves and nearly concedes the entire advantage of going first.

**a3 is the next strongest of the four**, and leaves *black* with a slight edge.

**h3 and h4 both leave black with a considerable lead.**

Now, that that's over with, will you finally listen to why *this doesn't matter*? If you're concerned with training purposes, you *don't want to train against a4* specifically. What you *want* to do is occasionally pick some purposely strange opening decisions that your kid has never played against. Did he reply to your e4 with the sicilian? Then try playing 2. b4 against him and see if he keeps his head.

*That's* why everyone is saying "Teach him opening fundamentals." Because you're *not* going to be able to train him on how to react to every strange/atypical opening move. There's simply too many of them. What you *can* train him on is how to react when your opponent starts doing stuff you don't expect.
> 7 votes

# Answer
Your kid did not lose the game because he did not know how to respond to that opening. He lost the game because he played worse! (by the way you're telling the story, probably because of a tactical blunder) I don't really think there is any human being on the planet who has prepared a line against 1.a4

I wouldn't really have a clear preference for any "rook pawn" opening. 1.a3 is sometimes played at "high" levels, as it could transpose to other openings where the a3-push is useful. h4 is a common attacking move, but only after Black has castled or, at least, moved the "g" pawn
> 6 votes

# Answer
How can 1.a4 be bad, when some guy named Magnus played it against a grandmaster and won? :-) See Carlsen-Radjabov (2012), from the World Blitz Championship.

Now, I don't think it counts as much preparation, but my rule of thumb against kids who open with 1.a4 is ...e5 and against h4, ...d5. I think ...e5 and ...d5 are both legitimately good moves, but the reason I pick the one opposite to the rook pawn is that I've seen those kids love their rooks, and their plan is often an early rook lift to a3 or h3, and they often to forget to look out for ...Bxa3 or ...Bxh3. Admittedly, this "trap" only works at the extreme beginner level, but that's the level where I've seen this opening (I haven't played against Magnus Carlsen), and if they don't blunder I didn't lose anything. Anyway, two things you could try if you want to simulate this kind of game against your kid are the rook lifts already mentioned, and early pawn storms.

Back to the original question, what's an "effective" rook opening? It seems to me that non-beginners who play such an opening basically treat it as a waiting move and then play a normal opening (the Carlsen example is basically a Four Knights Game after the 1.a4), perhaps trying to transpose to something where the move is useful. With 1.a4, you are roughly giving up a tempo, which means losing the first-move advantage, but at low levels of play this is not very important. Moving the h pawn may be worse because it has a bigger effect on king safety.
> 5 votes

# Answer
I made a terribly long book study of well-known and lesser-known unusual openings to contend with my grandpa's massive advantage in opening theory. He could match me in general openings, but I specialized. I would get the upper hand in the opening because he had no idea how to play against what I would produce. Of course he was still better than me and the game would turn around in the mid game ...

I can say categorically as follows from my book search:

* There are no known remotely good openings starting with a2-a4.
* The best response to a2-a4 is to advance the c, d, or e pawn two squares. I favor the c pawn because I favor the Sicilian defense, not because it's actually any better.
* The best way to play if you start with a2-a4 is to play a center-pawn opening with a wasted move. That is, you're now playing the matched center-pawn opening as black. It's possible that pushed pawn will be useful later, but probably not.
* If a rook is brought out early, it is likely to be chased around by minor pieces and can't meaningfully participate in the center battle.
* Don't deploy anything to b6.
* If a4-a5 is played, play a7-a6 in response.

If you really want to give your youngster some practice on this, play it and bring the rook out until he learns to chase it around. This play is unsound, but that's the point. Defending unsound gambits is something that needs to be practiced later on, so why not this now given your youngster is already facing it.
> 5 votes

# Answer
Actually, it doesn't matter how your opponent play the opening. You should teach your students to main aspects of the chess. In the opening, the goals are very clear. There are (mainly) 2 important things:

1. Importance of the center: Try to take control and dominate the center
2. Development: Try to develop your pieces as fast and as effective as possible - generally in order to their values. (pawns first, knights and bishops after, rooks and queen followed)

If you or your student basically apply the opening rules especially to an opponent who don't, then it can be an easy win with hight possibility. You would enter the mid-game with a big advantage and turning it into a clear win is up to you.
> 2 votes

# Answer
I'd like to give a more complex answer. I will give an opening that was played frequently \[at least by the standards of off beat openings\] at the highest level by people of Grandmaster Strength. That is the "Julian Hodgson" Trompowsky. 1. d4 Nf6 2. Bg5 Ne4 3. h4

At GM level against GM opponents that is the only opening that I can think of where a rook pawn move is for practical purposes playable. From an absolute theoretical point of view it will get the 3. h4?! symbol for dubious. But it is not clear over the board how to meet it as black and get any advantage. Hodgson, a strong GM, was also a specialist in the Trompowsky and he used 3.h4 a lot here in the 1990's. I haven't got the statistics offhand of his record with 3.h4. Apologies for not giving a diagram; not my strong point but could use one.

Obviously at the elite professional level of chess players are not usually going to open on the first move with a rook pawn. But a few moves later as here is possible. Of course if someone wants to be a smart alec and say well there's the fourth move of the main line Spanish then you can go ahead lol. Sorry that is a chess joke.
> 1 votes

---
Tags: opening, training, preparation
---


title: Unknown old FIDE players

text:
# Question
Title: Unknown old FIDE players
I am interested in the History of chess and looking at old FIDE ranking lists I am a bit puzzled by the lack of information about some very good players.

For instance, in the list of July 1972:

1. Shmit, from Soviet Union, and ranked #95 in the world with 2480 Elo https://www.olimpbase.org/Elo/player/Shmit.html
2. Zurakov, from Soviet Union, and ranked #275 in the world with 2415 Elo https://www.olimpbase.org/Elo/player/Zurakov.html
3. Abaharov, from Soviet Union, and ranked #285 in the world with 2410 Elo https://www.olimpbase.org/Elo/player/Abaharov.html

Does anyone know them?

The complete list offers other examples https://www.olimpbase.org/Elo/Elo197207e.html

I am also looking to know more about a player called Donnelly, from Ireland, and ranked #416 in 1970 with FIDE rating of 2240 (a very decent rating at that time!) https://www.olimpbase.org/Elo/player/Donnelly.html

# Answer
From Jeremy Gaige's *Chess Personalia: a biobibliography* (2005 paperback edition (originally from 1987), MacFarland), if no other source is given.

1) Shmit
Anatoly Shmit, a pseudonym, actual name is Anatolijs Šmits, p. 389
Anatolijs Šmits, born 1941.09.02 in Pskov gov., URS, p. 397
Pskov is a city in Russia very close to Estonia.
**Likely**

I found Anatolijs Šmits in wikipedia, where it's said he died on January 30, 1998.

2) Zurakov
Vladen Yakovlevich Zhurakov, born 1930.05.19, URS, p. 482
**Possibly**

3) Abaharov
Jarullakh Ibadullakh Ogli Abakarov, born 1934.05.10, URS, p. 1
**Possibly**

On page 280 of Gino Di Felice's *Chess Results 1956-1960* (MacFarland, 2010), Abakarov is said to be from Azerbaijan.

4) Donnelly
4.1) B. Donnely, IM in 1982, Zimbabwe, p. 97
4.2) Ruth Donnelly, born 1929.01.19, USA, p. 97
**Unlikely**

Next I looked at Edward Winter's Chess History website and found a *Donnelly* in his 1997 article War Crimes on Karlis Alexandrs Ozols. A game is given *Karlis Ozols – Donnelly* from the 1987 Correspondence Olympiad. It was a KID Ozols won in 24 moves.
Then I looked up the ICCF Chess Olympiad in 1987 and the preliminaries (no earlier records), but without success.

David McAlister's Blog Irish Chess History has a page about Irish Junior Championship. A *F. Donnelly* competed in 1954 in the Dublin Chess Club, but was not too successful (last place with 0/5).
> 5 votes

# Answer
I found one in Big Database 2016. Anatoly Shmit, born 1941 in Latvia, with 157 games between 1959 and 1989, all played within the USSR. Many strong Soviet players never got the chance to play outside the Soviet Union, and Shmit does not seem to have ever been awarded a FIDE title, although he was undoubtedly a very strong player, having beaten a number of well known players including Mikhail Tal.

According to chessgames.com, his name was more accurately Anatolijs Šmits. He won the Soviet Junior Championship in 1960, and was Latvian Champion in 1969 and 1975. He died in 1998, aged 56.
> 10 votes

# Answer
Perhaps the others are:

Vladlen Yakovlevich Zurakhov http://www.chessgames.com/player/vladlen\_yakovlevich\_zurakhov.html

and

Jarullakh Abakarov https://www.365chess.com/players/Jarullakh\_Abakarov
> 3 votes

---
Tags: rating, history, fide
---


# Question
Title: Where did this Emanuel Lasker quote come from?
In the book by the late master Irving Chernev "The Chess Companion" he gives a list of chess quotes. My favourite one was:

"The student can learn more in ten hours of properly tutored instruction than in 10 years of trial and error" : Dr Emanuel Lasker.

I might not have this quote absolutely right. If not this is very close; it might be the student 'would'...rather than the student 'can'. Anyway, I have never managed to trace this quote. Was it in Lasker's books, chess lectures such as the London lectures, or in his chess annotations? Or did he just say it? If so was it at a chess tournament or somewhere notable?

I'd like to know. Not out of skepticism. I have faith in Chernev. Rather, because it's my favourite quote! I also wonder if it was in German - Dr Lasker was German. If it is a translation then please keep in mind that I only understand English.

# Answer
> 6 votes
The correct wording is "properly taught, a student can learn more in a few hours than he would find out in ten years of untutored trial and error". The oldest reference to the quote I found is in this newspaper article of 1973.

# Answer
> 2 votes
The January 1953 Chess Review on the back of the front cover, right below *Chernev's Chess Corner*, has a "Thought for the month":

> Properly taught, a student can learn more in a few hours, than he would find out in ten years of untutored trial and error. -Ed. Lasker

This implies that it was Edward Lasker, not Emanuel Lasker, who said it. I didn't find its exact source yet, though.

---
Tags: history
---


# Question
Title: Can I reply to an illegal move with checkmate?
I was playing with my brother, and we both had equal number of pieces. He carelessly moved his king in the direction of my queen. I was about to checkmate my brother, but he told that my mating move was invalid. If his king comes in my direction and gets caught, I must say that I don't keep there.

I was confused. Can anyone please help me?

# Answer
> 6 votes
Yes. Putting your own king into danger is considered an illegal move. Depending on the context, illegal moves can be treated in different ways:

* In most casual games, players just agree to roll back to the position before the illegal move was made.
* In tournament games, the player who didn't make the illegal move gets 2 extra minutes on the clock. I guess this does not apply, as most likely you aren't playing with a chess clock. Anyway, the second illegal move is punished with a loss

Since you're playing a casual game with your brother, just go for the one you agree on!

# Answer
> 4 votes
If by "get caught" you mean the king moves such that it can be taken in one move, then yes you don't win the game. You must allow your opponent to take the move back. In official tournaments this would be counted as an "illegal move", and after 2 illegal moves from your opponent you win the game.

A checkmate is where you move a piece such that your opponent's king is trapped and attacked at the same time. It's not where your opponent's king steps into a direct attack on its own.

# Answer
> 3 votes
Moving your king into check (i.e. where it can be captured) is called an "illegal move".

If you are playing a casual game then you should put the position back to what it was before the illegal move was made and make a legal move.

If you are playing in a competition then more formal rules apply as specified in the sections of the FIDE Laws of Chess from article 6 onwards.

In a competition you play with clocks and the illegal move only counts as "completed" if you pressed the clock after making the illegal move. If you have not pressed the clock then you should just take the move back, play a legal move with the touched piece if possible and continue the game.

If you have completed the move by pressing the clock then you must also take the move back and play a legal move with the piece touched if possible but then additional penalties apply. These are spelled out in article 7.5.5:

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

These rules apply for all competition chess regardless of time control. Regardless of whether it is standard, rapid or blitz a second illegal move loses the game.

The only difference between standard time controls on one hand and blitz and rapid on the other is in determining that an illegal move has been made. In standard the moves are recorded and it is possible to detect an illegal move several moves later and also to return to the position before the illegal move. In the two quicker forms where moves are not recorded (world championships may differ in the respect that moves are recorded and so standard rules apply) and so slightly different rules apply regarding detecting that an illegal move has been made.

These are spelled out in Appendix A.4.2:

> **A.4.2** If the arbiter observes an action taken under Article 7.5.1, 7.5.2, 7.5.3 or 7.5.4, he shall act according to **Article 7.5.5**, provided the opponent has not made his next move. If the arbiter does not intervene, the opponent is entitled to claim, provided the opponent has not made his next move. If the opponent does not claim and the arbiter does not intervene, the illegal move shall stand and the game shall continue. Once the opponent has made his next move, an illegal move cannot be corrected unless this is agreed by the players without intervention of the arbiter.

So, in rapid and blitz the illegal move must be spotted immediately. If any more moves are made then the illegal move stands and the game continues. If the move is spotted by either the opponent or the arbiter then the normal rules apply and a second illegal move loses the game unless it is impossible for the opponent to mate.

# Answer
> 1 votes
There is a special case where you can reply to an illegal move with checkmate. In blitz chess different sets of rules exist. I have played blitz tournaments over the board where if you leave your king in check \[so you have made an illegal move\] the other player can "take" your king which is checkmate and they win the game. It's surprising how often that does happen. It's worth adding that the otehr player must make a move that "takes" your king. If they do not then you could make a legal move by getting your king out of check and the game goes on. In other words the player cannot just claim checkmate; they must make the legal move that captures the king.

---
Tags: rules
---


title: Joke Annotations

text:
# Question
Title: Joke Annotations
I have run into two examples of hilarious annotations of games over the years.

One is the "annotation" of the fake "Immortal Overprotection Game" Nimzowitsch-Systemsson, written by Hans Kmoch as a parody of Nimzowitsch's rather arrogant mannerisms.

The other is the "pipe game" Marshall-Burn. Burn always smoked at the board, and Marshall explains in great depth Burn's difficulties in lighting his pipe. At the end, Marshall writes "Poor Burn. I think I swindled him out of that one. If he could only have got his pipe going, it might have been a different story."

I find these both quite amusing. Does anyone know of any others?

# Answer
> 6 votes
Staunton: It seems utterly impossible for either player to save his game.

# Answer
> 3 votes
`Best by test` \- Fischer, waxing poetic on `1. e4`

`...making Kotov's face quite red.` Reschevsky, on burning Kotov with a tactic which exposed a back-rank weakness. I wish I could find the game!

# Answer
> 2 votes
This might not be to everyone's taste, but the following annotated game (like the novel it's taken from) is hilarious in it's own way:

Murphy vs. Mr. Endon

# Answer
> 2 votes
Two examples from **Vladimir Kramnik**, taken from Kramnik, Vladimir; Damsky, Igor: *My Life and Games*, Everyman Chess, 2000.

1) *A smile in the endgame*

Position after 48.Ne5:

```

    [Title "Kramnik, Vladimir - Ivanchuk, Vasily, Las Palmas 1996"]
    [FEN "8/6K1/7P/4N3/8/k7/8/1b6 b - - 0 0"]

1...Kb4 {The black king is hurrying towards g5.} 2. Ng6 Bxg6 3. Kxg6 {And in view of the variation 50...Kc5 51.h7 Kd6 52.h8=Q my opponent finally resigned.}

```

Game 151, p. 194

Link to the game

2) *In the mystification genre*

Kramnik annotates Kramnik, Vladimir - Timman, Jan, Wijk aan Zee 1999 (game 173) on pp. 250-254 in an unusual manner. Her parodies commenters:

> I have often begun noticing that the commentaries of certain well-known (and not so well-known) players would be correctly characterised as "frankly hack-work", by no means aimed at searching for the truth.

He then goes on to give 4 reasons, that I paraphrase

1. Winner wants to make it seem like their opponent "was doomed \[...\] even before the first move".
2. Doesn't want to recognize own mistakes.
3. Doesn't want to waste their time and effort on commentary.
4. "Anything else."

But he believes that the 3rd reason occurs more often than all the others.

Then comes *Part 1* of the commentary (move 1 to 41), followed by *Part 2* (moves 26 to 36). *Part 2* concentrates on specific moves and is much more thorough. It turns out that annotations from *Part 1* from move 26 onwards are parodies of the above mentioned commenters. They are short, but authoritatively sounding, and are refuted in *Part 2* which is much more critical of both, Kramnik's and Timman's moves.

> After all that has been said, it becomes clear that the play of both players in the game was far from ideal. \[...\]

Link to the game

# Answer
> 1 votes
There was a humorous analysis of the old line of the Berlin Defense (where Black plays .. bxc6 and then after e5 retreats with Nd6-b7) by the writer Assiac. It may have been in "The Fireside Book of Chess." The tone of the piece was mocking, putting down how ugly "modern" chess theory was...

---
Tags: history
---


# Question
Title: What to choose to play as black if you play King's Indian Attack as white?
I am around 1700 - 1800 player on chess.com, mainly playing 3+2 and 5+5 games and as white I always play KIA, but what I have noticed recently is that with white my score is much better that as black - with white I have 40 victories more than losses, but with black I have only 8 victories more than losses.

So, I was wondering what opening one should play with black if he plays KIA as white?

I have tried French, Sicilian Kan and Pirc, and maybe I had the most success with Kan, but again it is nowhere near as good as my performance with white.

# Answer
The King's Indian Attack isn't called the King's Indian Attack for nothing; it's White's version of the King's Indian *Defense* which is an opening for Black, characterized by the moves 1. d4 Nf6 2. c4 g6, and Black intends to follow up with Bg7, d6, castling kingside and either c5 or e5. So you should get a structure you're familiar with, although the precise moves may be different.

You can't really play the KID against 1. e4, so you'd have to opt for the Modern Defense, or the Pirc you already mentioned. If you're attracted to the setup with g6 and Bg7, the Sicilian Dragon would also be an option.

> but what I have noticed recently is that with white my score is much better that as black - with white I have 40 victories more than loses, but with black I have only 8 victories more than losses.

Depending on the strength of your opponents and the number of games you play, this can be quite normal. By moving first, White has a slight advantage and (at all levels of play) this implies players score better with White than with Black. I wouldn't really worry about it for now.
> 5 votes

---
Tags: opening, kings-indian-attack
---


# Question
Title: What is an accurate way to evaluate chess positions?
I've been interested for a while about a computer chess AI algorithms (and got the chance to work on one at some point) like Minimax, and as the core component of these algorithms is the so-called **evaluation function** to determine what is a *good* board configuration, and what is a *bad* one.

In other terms, given a configuration of your Chess board, how do you determine that it is to your advantage, and with what degree of confidence?

For example:

* If you *own* the center, this is rather favorable.
* If you have more pieces than your opponent, this is rather favorable.
* If you lost your Queen, this is rather not favorable.
* If you have a pawn that is close to being promoted this is favorable.
* ...

So I would like to ask for some advice on how to create a *good* evaluation function, based on some expert knowledge about the Chess game in general. And if possible, a degree of favorability (say between 1 being very not favorable, to 100 being extremely favorable).

The idea in the end is to be able to create an algorithm that will look in the tree of possibilities up to a certain depth and evaluate what the most favorable configuration for next move is (taking into account several moves in the future) based on what is favorable to the player and not favorable to the opponent. But without a good evaluation function the algorithm is nothing.

# Answer
Here's a good starting point. Material comparison is key (and easy), then you can tune that to consider positional aspects like open ranks/files/diagonals, pawn structure, etc.

https://www.chessprogramming.org/Evaluation
> 11 votes

# Answer
I have a feeling I'm a little late on this answer but - I'm also in the process of making an engine. The source code is in Python (which is fairly easy to read, even if you don't know it) and is available here if you wish to read it. The list of currently active 'heuristics' (at the time of posting):

* Farther developed (closer to the opposite side) pieces are better
* Pawns closer to promotion are good
* Kings are scored separately based on what phase the game is in (opening, middlegame, endgame)
* If the player has both bishops, that receives a bonus
* If the player has castled, receive a bonus
* Isolated pawns (pawns with nothing around them) are not good
* Doubled pawns (two pawns on the same file with no gap between) are not good
* Having all 8 pawns is not necessary a good thing and is penalized (they clutter the board and get in the way)
* Have a look at this great evaluation function which is also used
* Bishops with more pawns on the same color square as the bishop are penalized (they aren't as good in crowded situations)
* Not yet implemented, but planned: Knights get a bonus in more crowded situations

In one of those points, I mentioned the 'phase' of the game (e.g. opening, middlegame, endgame), and if you wish to include that in your engine, you'll probably run into the same problem as I did: there's no clear line separating those. My function that decides what phase the game is in uses a few things:

* Amount of material on the board (as soon as any piece is killed, it marks the game as not in the opening)
* Number of moves (less than 6 full moves is the opening, no matter what)
* movement of the queens (if both queens have been moved, mark the game as middlegame)

This answer may have been long, late and off-topic, but I hope it was helpful anyways.
> 9 votes

# Answer
Adding up to the answer by @Eve Freeman, I would suggest looking up how does the best computer engine in the world, Stockfish, evaluate a given position. As the source code is open, you can do it for free. I think the file with the evaluation function you are looking for is this one.
> 6 votes

# Answer
Surprisingly, it turns out that a Minimax engine will play reasonably well when the evaluation function is **random**; this is known as the Beale effect, and results from the principle that positions which give you more options and your opponent fewer options are generally favourable. One reasonable way to generate random evaluations consistently and efficiently is to generate a Zobrist hash for the position (using coefficients chosen randomly at the start of the game), and derive the random evaluation directly from the hash.

At the opposite end of the scale, AlphaZero and Leela conduct an extremely sophisticated evaluation of each position searched, using a **large neural network**. It is impractical to describe in human terms what functions this network effectively implements, but it is undeniably more effective than Stockfish's evaluation function. The AlphaZero research paper indicates that this approach works best with Monte-Carlo Tree Search rather than Minimax.

If, on the other hand, you want to develop an **analysis engine** to help human players or commentators understand the nuances of a position, it may be worthwhile to implement a conventional evaluation function using **established material values and positional theory**. A good example is set by Ed Schröder's *Inside Rebel*, documenting the major design features of a well-regarded engine used in several of Mephisto's chess computers. You may wish to use a certain degree of machine learning to determine the relative importance of each element of your evaluation function, and also break out these elements individually for presentation in a GUI.
> 5 votes

# Answer
I think chess programmers tend not to rely on the knowledge of strong chess players when designing their evaluation functions, but instead try out different elements, and then test them in games against other engines, and decide what to keep. Larry Kaufman talks a fair bit about his views on what a human's understanding is, but it sounds like both Rajlich and Dailey were very results oriented, and did not adopt Kaufman's ideas wholesale.

One article I found interesting was Zach Wegner comparing the evaluation functions of Rybka and Fruit. One of the areas where Rybka may have represented a step forward was in its incorporation of material imbalance tables based on specific combinations of pieces. Kaufman wrote an article on this as well.

http://www.top-5000.nl/ZW\_Rybka\_Fruit.pdf http://danheisman.home.comcast.net/~danheisman/Articles/evaluation\_of\_material\_imbalance.htm
> 4 votes

# Answer
This link is the best starting point IMHO. I am using this as my starting point for my own chess program & finding it simple to understand and useful too.

https://chessprogramming.wikispaces.com/Simplified+evaluation+function
> 0 votes

# Answer
In a nutshell, the standard approach to tuning a chess engine's parameters is to:

1. Define the parameters
2. Give the parameters nominal (starting) values
3. Run the engine to see how it performs
4. Tune the parameter values to try to improve its performance

Then repeat Steps 3 and 4 until you've reached your goal for performance.

The usual approach to doing this is to set up a laboratory where engines face off in engine tournaments. Multiple games are used in which the engine plays both colors. The main tournaments of interest involve running an engine with parameter value set A against the same engine with parameter value set B.

As you can probably guess, results from this approach are heavily dependent on:

* The parameters chosen
* How the parameters are specified
* How the parameter values are varied throughout the testing
* How the engines are run (limited ply-depth, limited time, sensitivity, etc)

This approach also consumes *a lot* of time.

A more recent (and innovative approach) was developed in 2010 by researchers using Genetic Algorithm techniques to a) specify the parameters, and b) tune the parameter values. The investigators first ran an engine with a starting, nominal set of parameter values against a *set of grandmaster games* to see if it could effectively choose the "best move". The "best move" was defined as the move the grandmaster made\*. Wherever it failed to do so was recorded. Then, another parameter value set was tried, and relative performance vs the prior run determined.

Then, a programmatic approach to *combining the parameter values* was tried, using the Genetic Algorithm principle of survival of the "fittest". Here, "fittest" means the one that generates output that most closely matches the ideal. (It also happens to be a pun on the statistical technique of "least squares fit" regression, a technique used to judge the quality of the approximation.)

Only after engine parameters have been found that can mimic a GM reasonably well does the actual engine tournament phase begin. In this phase, different parameter value sets are once again pitted against each other, this time *directly*. Genetic Algorithm improvement techniques are applied to generate successively better generations of the engine.

In this research project, 36 parameters were used, including all of the material values of the pieces, and many of the more common strategic evaluation criteria, such as backward pawns, weak squares, bishop pair, and so on. However, the researchers added some new parameters, such as "king pressure", "mobility" values for each kind of piece, rook on a file adjacent to the king, rook on a semi-open file, rook attacking the king on the a-/b-/g-/h-file, separation between a passed pawn and the defending king, and more.

Unfortunately, the researchers don't elaborate on how they came up with this suite of parameters, and what alternate parameters they may have tested and rejected. It would be reasonable to assume that they began with a much larger set, and determined (through trial and error) which ones had the greatest effect on performance, and which ones were either insignificant or derivative, and so could be dropped.

If this sounds like it might be useful, you can find the research ***here***.

\*A caveat about a phase of the approach that the researchers used is in order. In his Introduction to *Understanding Chess Move by Move*, John Nunn chose "...hard fought games between strong grandmasters..." to illustrate his themes. He then adds:

> Readers may be quite surprised to see the number of question marks that adorn the games in this book. Surely, you might think, with just thirty games to select, it should have been easy to find some sound games. However, I can assure you that it was not. ... it is possible to find fault with virtually any complex, hard-fought game... I have never felt that my play was anywhere near completely accurate, so I personally don't find these revelations distressing. However, some may find it hard to admit that chess as played by human beings is less accurate than previously thought.

The point that Dr Nunn raises suggests that the researchers' initial approach to setting the engine parameters by requiring them to imitate grandmaster moves may be flawed *because human play is flawed*. In fact, it's well established that *engines already play better than humans*.

Therefore, perhaps a better approach to setting the initial parameters would be to match a new engine against *a superior existing engine*.
> 0 votes

# Answer
There is a nice website at:

> https://hxim.github.io/Stockfish-Evaluation-Guide/

It gives you an introduction on how the Stockfish functions work.
> 0 votes

---
Tags: engines, positional-play, evaluation, chess-algorithms
---


# Question
Title: Was Wolfgang Unzicker the last Amateur GM?
Wolfgang Unzicker was a German GM, rated about 2550 and worked as a judge. In the sense of holding down a job while playing, he was an "amateur" player.

So was Unzicker, a GM in the 70's, the last amateur GM?

# Answer
> 17 votes
The economist Ken Rogoff (b. 1953) achieved the GM title in 1978, but was never a "professional" chess player. Rogoff is currently a professor of economics at Harvard University.

# Answer
> 33 votes
> So in the sense of holding down a job while playing he was an "amateur" player.
>
> So was Unzicker, a GM in the 70's, the last amateur GM?

No. Here are 4 current British "amateur" grandmasters.

* English GM Matthew Turner is a teacher at Millfield School in Somerset.
* English GM Matthew Sadler is a computer consultant in the Netherlands.
* English GM Luke McShane (currently on 4/7 in the Netanya Masters) is a financial trader in London
* Scottish GM Dr. Jonathan Rowson is Director of the Social Brain Centre at the Royal Society of Arts in London

# Answer
> 12 votes
There are plenty of GMs that do not play professionally, e.g. GM Luke McShane is a financial trader, GM Hou Yifan is a Rhodes scholar. So if your definition of "amateur" is holding down a job while playing occasionally, Wolfgang Unzicker certainly was not the last amateur GM.

---
Tags: grandmaster
---


# Question
Title: What are some stronger moves I can play next time in the King's Indian Defense?
```
[fen ""]

1. d4 Nf6
2. c4 g6
3. Nc3 Bg7
4. e4 d6
5. Nf3 O-O
6. Be2 e5
7. O-O Nc6
8. d5 Ne7
9. Ne1 Nd7
10. Be3 f5
11. f3 f4
12. Bf2 g5
13. b4 Nf6
14. c5 Ng6
15. cxd6 cxd6
16. Rc1 Rf7
17. Nb5 a6
18. Nc3 Bf8
19. Na4 Bd7
20. Nb6 g4
21. Nxa8 g3
22. hxg3 fxg3
23. Bxg3 Nh5
24. Bf2 Ngf4
25. Nb6 Rg7
26. Nxd7 Qxd7
27. Kh2 Nxg2
28. Nxg2 Rxg2+
29. Kxg2 Nf4+
30. Kg1 Qh3 0-1

```

I won that game, but I feel like I got lucky. I blundered in this game. I feel that letting white capture my rook on a8 was a blunder. Also what if white captured g4 then I have to capture e4 with my knight. White then captures my rook at a8. I don't see any compensation for black for the lost of material. I also don't see how to continue the attack through this variation. What could I have done better as black against my opponent? What are some key ideas in the King's Indian Defense that I missed in this game? What concepts should I grasp from this game I played to become a better chess player and better using the King's Indian Defense? When is it the right time to give up the rook on a8 for an attack on the king side?

# Answer
> won that game, but I feel like I got lucky. I blundered in this game. I feel that letting white capture my rook on a8 was a blunder

Everything you said was correct.

> Also what if white captured g4 then I have to capture e4 with my knight. White then captures my rook at a8. I don't see any compensation for black for the lost of material.

Again, I agree with your conclusion.

> I also don't see how to continue the attack through this variation.

You can't, because White plays `Rc7` and keeps everything under control. Even if you "get" classical `...Bh3` sacrifice he will have `Rxc7+` in that setup and your attack is dead. Bishops and knight will easily repel your minor pieces, not to mention that extra rook... Since it was long time since I played actively KID ( both as Black and White ), I had to check theory as well. You missed the **key move** `19...Nd7!` which stops White queenside action in its tracks, in my opinion. This is also the move theory recommends.

> What could I have done better as black against my opponent?

I think your first mistake, and very serious one, was `19...Bd7?!`. I would simply follow theory and respond with `19...Nd7!`, stopping White's shenanigans at queenside. His attack is severely slowed down, while you can continue the attack with `...h5`. This is the only important moment you can use in this game to improve.

Aside from that, you made some serious blunders he could have exploited. After he took the rook the game was over, but you managed to "come back". In many occasions you gave him a chance for turnover, which is a result of poor combinational skill. You need to practice more, especially when you play this opening, and especially when you play this line. Tactics is everything for Black here! See the comments in the game below to see all the mistakes and suggested improvements.

```
[Title "Game analysis"]
[fen ""]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6 8.d5 Ne7 9.Ne1 Nd7 10.Be3 f5 11.f3 f4 12.Bf2 g5 13.b4 Nf6 14.c5 Ng6 15.cxd6 cxd6 16.Rc1 Rf7 17.Nb5?! ( 17.a4!? ) 17...a6 18.Nc3 Bf8 19.Na4 Bd7?! ( 19...Nd7!? ) 20.Nb6 g4? ( 20...Rb8!?+/= ) 21.Nxa8+- g3? ( 21...Qxa8 22.Rc7+- ) 22.hxg3 ( 22.Nc7!? gxf2+ 23.Rxf2) 22...fxg3 23.Bxg3 Nh5 24.Bf2 ( 24.Bh2!? Bh6 25.f4 Nhxf4 26.Bxf4+- ) 24...Ngf4 25.Nb6 Rg7 26.Nxd7?? ( 26.g4!+- Nh3+ 27.Kh1 Nxf2+ 28.Rxf2 Qxb6 29.Rh2 ) 26...Qxd7?? ( 26...Rxg2+! $8 27.Nxg2 Qg5-+ ) 27.Kh2?? ( 27.g4!+- ) 27...Nxg2?? ( 27...Rxg2!+ $8 28.Nxg2 Qh3+ 29.Kg1 Qxg2# ) 28.Nxg2?? ( 28.Rc7!! Qc7 29.Nxg2+- ) 28...Rxg2+ 29.Kxg2 Nf4+ 30.Kg1 Qh3 0-1

```

> What are some key ideas in the King's Indian Defense that I missed in this game?

You missed nothing, push `...f5` -\> deliver checkmate or die. The concept is easy to grasp :)

*The only time you sidestep this pattern is in Yugoslav attack, but that is a different story ( White there goes for fianchetto with `g3 + Bg2` ). In that case you prepare exchange sacrifice with `...Rxb2!`, but this is off-topic here. If you need further questions about this line post them as a new question.*

> What concepts should I grasp from this game I played to become a better chess player and better using the King's Indian Defense?

You can't play this line unprepared, you **must** know theory of this line very well.

This line is so forced that one wrong move will cost you the game. Already after `19...Bd7?!` White stood better! You had no counterplay after that, and if you played `...Rb8` he could simply take your light-squared bishop and destroy **every** mean of counterplay you have ( **the point of this line is to sacrifice that bishop for `h3` pawn** ). Without your key attacker, your attack would be dead, while he would first bolster his kingside, and then demolish you on the queenside, since you would have no natural kingside counterplay.

Second thing, your tactical skill must be very high, because this line relies solely on that. There are no "hidden gems" it is raw and simple -\> mate or die. You missed several times clean win which gave him the chance **to win the game**. I hope you will understand just how devastating blunders, or even imprecise moves, can be in this line, so please sharpen your tactical skill.

Third, play "clean chess". After `27.Kh2??` you had "clean victory" with `27...Rxg2+! 28.Nxg2 Qh3+ 29.Kg1 Qxg2#` yet you decided to complicate with `27...Nxg2??` after which he could have **won** the game with `28.Rc7!!`. Always aim **to destroy opponent's counterplay**, especially in these positions. If you have a queen and pawn versus rook, give the queen for the rook and win simple pawn endgame. In this opening, and in this mainline, there is always venom in position and "playing with fire" can backfire, in view of you stalemating the opponent or not seeing some cheap tactics. **If you have a forced win, then by all means, win by force!**

> When is it the right time to give up the rook on a8 for an attack on the king side?

Only if you are certain that your attack is so strong that it will at least get you perpetual check or will win you back the material. Other than that, forget it!

## SUMMARY:

Well played, keep sharpening your tactical skill and learn theory to the **last** book move. Always aim to win the easiest way because this line is minefield and you never know when you will allow your opponent to play some crazy intermediate move that will give him magnificent comeback ( or maybe you will blunder a cheap tactical shot ).

If you have further questions leave a comment. Best regards.
> 5 votes

# Answer
Actually, I don't think a6 was a good move. In those structures, I would be very careful to push the a-pawn too early. At some point it might be necessary of course, but this was too early in my opinion.

Instead you could consider 17... g4, because a common motif in these structures is that 18. fxg4 is bad due to 18... Nxe4 with grabbing away the dark squared bishop.

After 17... g4 18. Nxa7 Bd7 one important point to notice is, that 19. Bb5 fails due to 19...g3! ( 20. hxg3 fxg3 21. Be3 fails to the standard 21... Nxd5 with Qh4 to follow up, while 22. Bxd7 fails due to 22...Nxe3). So after 18. Nxa7, Whites play is simply too slow, and blacks attack is way to strong - therefore there is no need to defend a7 at all.

On every other whites move then 18. Nxa7, you can simply play 18... g3 with the follow-up g3 hxg3 fxg3 Bxg3 Nh5 Bh2/f2 Ngf4 and a strong attack.

Therefore Nb5 might actually be already quite a blunder.

There is one thing you should always check before playing a6: That's the Na4-b6 idea. To avoid this, you should play a6 mainly, if Na4-b6 is either too slow to prevent the king side attack, or if a6 Na3/c3 b5 is possible with avoiding the nasty knight jumps.
> 1 votes

---
Tags: opening, analysis, kings-indian
---


# Question
Title: Fairy endgame statistics for KDDDDvKN (D=dabbaba; '2,0' leaper)?
The dabbaba is a '2,0' leaper fairy piece, only able to ever reach a quarter of the squares on the board. According to the linked Wikipedia page, a quartet of them can apparently "easily" force mate against a bare king with the help of their own king; however, I'm curious whether an orthodox knight could reliably hold off the dabbaba quartet. It's effectively a 7-piece endgame, just that 4 of the pieces are weaker fairy pieces; four '2,0' leapers that can each only reach a quarter of the squares on the board versus a single '2,1' leaper that can reach any square on the board.

As for the dabbaba's aforementioned restriction to a quarter of the squares on the board, a single dabbaba can reach either ACEG or BDFH files and either odd ranks or even ranks; making the 4 dabbabas of the quartet be the odd ACEG, even ACEG, odd BDFH, and even BDFH. Assuming the 4 dabbabas are to cover their respective quarters of the board, there should be ((16^4)/8)\*(60!/(60-3)!)\*2 meaningfully unique KDDDDvKN positions to look at minus any where side-to-move could just take the other side's king or is already checkmated by the other side.

# Answer
> 4 votes
I was unable to generate data for exactly what you want, but I managed something with a restriction to 6x6 board. I think it's reasonable to assume that it doesn't make a big difference from 8x8 for this specific case since there are no powerful pieces on the board (with unrestricted movement distance).

Available positions are enumerated by starting from a certain position and doing moves until we can. It should give all possible positions but I'm not sure. (I respect the requirement posed by OP that all Ds have different available positions)

Code (C++17, uses a few MSVC specific intrinsics) (tuned for this specific piece types and configuration): https://pastebin.com/d6J5WHuY

Stripped WDL data:

```
        W               D               L
KvK     0.000000000%    100.000000000%  0.000000000%
KDvK    0.000000000%    0.000000000%    0.000000000%
KDDvK   0.620803000%    99.379200000%   0.000000000%
KDDDvK  25.666000000%   74.334000000%   0.000000000%
KDDDDvK 69.638300000%   30.361700000%   0.000000000%
KvKN    0.000000000%    100.000000000%  0.000000000%
KDvKN   0.000761905%    99.997700000%   0.001523810%
KDDvKN  0.083948400%    99.916000000%   0.000000000%
KDDDvKN 3.553240000%    96.446800000%   0.000000000%

```

```
        Longest DTM for white
            Longest DTM for black
KvK     0   0
KDvK    0   0
KDDvK   17  0
KDDDvK  57  0
KDDDDvK 63  0
KvKN    0   0
KDvKN   1   1
KDDvKN  17  0
KDDDvKN 63  0

```

I'm unable to generate KDDDDvKN as it would require ~32GiB of RAM (should take less than an hour though), which I don't have.

Buf overall it can be seen that around a quarter of KDDDvK games are winning for white which may suggest that there are non-trivial winning KDDDDvKN positions.

I also have more detailed logs with the longest winning line shown. https://drive.google.com/drive/folders/1\_aLMYB87zVJ9qslQxafTZNKHgXsoBnl2?usp=sharing

I have not added any persistence/querying and I don't plan to. Code is provided above.

# Answer
> 1 votes
Hi welcome to chess stackexchange. If I had a Knight surely I can trade it for one of these Daddaba guys. So a simpler question is whether KDDD can beat K. If the lone K can reach the corner where he can’t be checked, then he is safe.

---
Tags: endgame, chess-variants, unorthodox-pieces
---


# Question
Title: How can I use pgn-extract to remove a game from a pgn file when there is an illegal move?
How can I use pgn-extract to remove a game from a pgn file when there is an illegal move?

# Answer
> 8 votes
pgn-extract will do exactly that if you give it an input file and say where you want the correct games to go. For instance:

```
pgn-extract --output clean.pgn games.pgn

```

will put only the valid games from `games.pgn` into `clean.pgn`, reporting any errors on standard output. If you want to have a record of the errors then you can use the -l flag to specify a log file; e.g.:

```
pgn-extract --output clean.pgn -lissues.txt games.pgn

```

There are lots of additional options/flags described in the documentation.

Disclosure: I am the author of pgn-extract.

---
Tags: illegal-move
---


# Question
Title: Looking for an old problem that I can't quite remember
I remember seeing a particular chess problem awhile ago on YouTube, but I can't find it. The problem's theme was something about caging in the Turkish king, and the video mentioned it as being old.

Regarding details of the problem, here are two. It ends in a smothered mate with eight black pawns surrounding the Black king. In the course of the solution, all of the Black pawns are forced into place by White.

Here is example I've made of the general concept.

```
[FEN "8/2pKN3/Q3ppp1/2ppk1p1/4pR2/3P1P2/4N3/8 w KQkq - 0 1"]

1. Qd6+ cxd6 2. Rf5+ gxf5 3. d4+ cxd4 4. f4+ gxf4 5. Ng6#

```

Does anyone know the problem and its source?

# Answer
> 9 votes
```

    [Title "Carl Ferdinand von Jänisch, Der eiserne Käfig des Tamerlan, 1849"]
    [FEN "4N3/P2p1Np1/3Qp1R1/2pR4/2p1kpp1/b2bp2B/q3PP2/3K4 w - - 0 0"]

1.f3+ gxf3 2.exd3+ cxd3 3.Bf5+ exf5 4.Re6+ dxe6 5.Nf6+ gxf6 6.Rd4+ cxd4 7.a8=B Qd5 8.Bxd5+ exd5 9.Qe5+ fxe5 10.Ng5#

```

It's problem 59 in Max Lange: *Handbuch der Schachaufgaben*, Leipzig 1862, p. 79. Google Books.

It was published on p. 427 of the 1849 *Schachzeitung*. Google Books.

The chess puzzle can also be found with the search term `tamburlaine's iron cage`, e. g. Suren's YouTube video.

# Answer
> 5 votes
Is it this one?

```
[Title "Herbert Grasemann. Deutsche Schachblätter 1950, 2nd Prize"]
[StartFlipped "0"]
[fen "8/8/8/5B2/6QN/3prp2/3r1p2/3bbk1K w KQkq - 0 1"]

1.Qh3+ Ke2 2.Qf1+ Kxf1 3.Bh3+ Ke2 4.Bf1+ Kxf1 5.Nf5 Ra2 6.Ng3#

```

Dickin & Ebert, in their *100 Classics of the Chessboard*, no. 55, call it "Back into Clink".

If not, if the bK really is surrounded by 8 pawns and no pieces, then perhaps it was one of the problems as located by this PDB query:

http://pdb.dieschwalbe.de/search.jsp?expression=PIECELIST='Sbbbbbbbb'+AND+WPIECES=3+AND+G='n%23'

---
Tags: history, problems, identify-this
---


# Question
Title: Converting from Algebraic notation to Coordinate notation
I saw this thread: Converting square notation to algebraic notation programmatically

Unfortunately, it's the reverse of what I need to do.

Given a FEN and an Algebraic move, I need to generate the coordinate notation of said move.

I realize that you need the position (FEN) in order to reverse engineer the starting position of the pawn/piece being moved.

I'm hoping there is some utility or library/function that does this. If not, a description/outline of the basic algorithm would be great too.

# Answer
> 6 votes
You can do this easily in python using the python-chess module and using the `parse_san` function of `chess.Move.`

Let's call the script `algebTocoord.py`:

```
import chess

testfen = 'rnbqkb1r/pppppppp/5n2/8/3P4/8/PPP1PPPP/RNBQKBNR w KQkq - 1 2'
board = chess.Board(testfen)
algmove = 'Nf3'
coordmove = str(board.parse_san(algmove))
print coordmove

```

the printed output is:

```
'g1f3'

```

This was tested using Python version `2.7.16` and the `0.22.1` version of python-chess.

---
Tags: programming, notation
---


# Question
Title: Can almost anyone become a grandmaster if they devoted their life from age 6?
I hope that some stronger players have some insight or that their are some quotations from notable chess players that relate to the question.

# Answer
> 10 votes
If you look only at the number of people that are obviously intelligent and put a lot of effort into their chess, and then look at the tiny fraction that achieve the level of national master or Candidate master (never mind the higher levels of FIDE masgter, International Master and Grandmaster) then it would seem that the answer is no, not everyone can become a Grandmaster.

But this begs the question. We do not know what made the difference. Was some of that effort and intensity wasted in the wrong sorts of study? Is some mental skill present in those that succeed that could have been developed in anyone if we only knew how? Does luck play a part? \[Being in the right place, finding the right coach, stumbling on the right books, scoring highly your first tournament\]. Or was it genetic?

The Pólgar experiment tells us nothing. It does not disentangle genetics from environment. László Polgár would have done well to learn something about designing experiments before he started. Then he might have adopted a child or two and compared their chess development to the biological children so as to exclude the genetic influence. Even then the results would not have been conclusive: a handful of subjects do not produce a statistically significant result.

Achieving excellence in chess is no different than achieving excellence in anything. There might be a genetic component. Where you live and are raised makes a difference to your opportunities and the quality of your training. Hard work is mandatory (even if some prodigies would prefer you to believe that it all came to them easily without ever having to work hard - because that is a myth).

What is the answer to your question? It is simple. It is the answer to many questions. It is not one that is popular. It is the reason for interminable debates and arguments, for cherry picking and for much opinion dressed as fact.

WE DO NOT KNOW!

# Answer
> 8 votes
I knew a guy from high school, whom I would characterize as a "genius," who is (now in his 50s), barely a master, that is, about 2200. He was a "teen prodigy" that won our league in our city in those days, for his age bracket. He was also a chess "hobbyist," who devoted most of his non-study/non-professional time to chess.

Mark could probably have become a grandmaster if he had devoted his life to it. But most less-gifted people cannot do this, even if they "try."

# Answer
> 2 votes
Well, that's a rather tough question. My answer is probably no, not everyone can become a grandmaster. Devoting yourself to chess to that extent requires tremendous amounts of time and money, which most don't have. If you really aim that high you'd have to neglect education and finally you would never be so sure you'll become a grandmaster. I think only those with true love and devotion for chess can go that far, because people aren't robots, you can't just make everyone love chess and force them to go as far as becoming grandmasters, I believe it depends on the person. However, if you have the 3 factors, deep love for chess, money and time, I do believe that such people can and will reach grandmaster level if they try hard enough. :)

# Answer
> 1 votes
There are a number of factors that would impact this, not the least of which is a strong desire to excel. A good memory is very important nowadays with the mass of opening variations and computer analysis having solved all the various types of endgames which you'd have to learn. The willingness to fight and nerves of steel are also important as well as a mortal fear of losing. And even with desire, talent is still significant. I know that some people will say that it is mainly hard work that will get you to the top. I worked all my life at chess but could never even get to Expert, peaking at a rating of 1891 over a decade ago. There are obviously some people with greater aptitude for the game who will excel at it, all other things being equal. How else do you account for prodigies like Morphy and Capablanca? Chess was their "native tongue". Not everyone can be an Einstein no matter how hard he works. How about Fischer's supposed reincarnation, Josh Waitzkin? He never made it even with all his advantages. The short answer is that hardly anyone can become a Grandmaster no matter how hard he works without inherent ability, a photographic memory, the willingness to spend a large proportion of his waking hours studying and practicing chess, plus a fanatical desire to win. And even those are no guarantee.

# Answer
> 1 votes
There is really no definite answer on this.

To check this hypothesis, we would need to get a sufficient number of random children aged six and force them (against their own will and that of their parents if necessary) to devote themselves to chess under the same conditions (e.g. trainers, books). This would be clearly unethical. With the Polgar family you have obvious selection bias.

Another practical problem is that if you pick too many children, you made it harder for each individual one of them to become a grandmaster (as you have to be successful in competition).

I suspect that a high percentage (but not all) of the children sufficiently pressured would make it, considering how easily children learn new languages at that time. But that is a personal feeling.

Personally, I find the Polgars still instructive. I regard them as weak evidence that the male/female differential is mostly cultural, which may indicate that the same could be true other strength differentials in chess.

# Answer
> 0 votes
What I have seen mostly is that people with 2400+ ratings had a very good genetics i.e. atleast one of their parents played Chess before or intelligent in their field. This absolutely boosts their children's Chess skills.

It is also dependent on your memorizing skills and having a clear mind. That's why Chess players indulge in physical activities boosting their body which ultimately leads to healthy mind. Vishwanath Anand likes to go to Gym in between Chess rounds. They cannot just devote their life for Chess and succeed.

# Answer
> 0 votes
No, the higher you go the bigger the role of innate intelligence becomes a factor. Less than 1% of Fide rated chess players are grandmasters (about 1500 people around the world). If you consider the number of grandmasters as portion of all people who play chess, that percentage is much smaller.

# Answer
> 0 votes
It depends on what do you mean by "almost anyone". I think that any intelligent, focused, and with no other faults, individual, could make it if "they devoted their whole life to chess from age 6", especially if they could afford the best trainers and so on and on. GM is just a title, it means that you are a very strong player. That doesn't mean you are going to beat Carlsen or become US champion.

---
Tags: learning, grandmaster
---


# Question
Title: Where can I find Pauls' 1874 article on the n-queens problem?
Where can I find the following article, which concerns the n-queens problem?

> E. Pauls, Das Maximalproblem der Damen auf dem Schachbrete, II, Deutsche Schachzeitung. Organ f¨ur das Gesammte Schachleben 29 (9)(1874) 257–267.

# Answer
Nick Pope's web site Chess Archaeology has a page titled "Chess Library" where he lists a number of on-line chess periodicals.

http://www.chessarch.com/library/library.shtml

And, yes, the volume of DSz that you're asking for can be found there.

For German sources, the Deutsche Digital Bibliothek (https://www.deutsche-digitale-bibliothek.de/) can sometimes be useful:

https://reader.digitale-sammlungen.de/de/fs1/object/display/bsb11184017\_00259.html
> 4 votes

# Answer
The only old documents I find available online from the *Deutsche Schachzeitung* periodical are from Volumes 20, 21, 44, 45, 56, 57, which are available at the Internet Archive. So if you really are after Pauls' exact article for historical reasons, you might have to track down a hard copy of Volume 29 at a library.

On the other hand, if you are primarily interested in the mathematical content of Pauls' article, then a decent (though also partial) exposition is available from "A survey of known results and research areas for n-queens" by Jordan Bell and Brett Stevens, in *Discrete Mathematics* Volume 309, pp.1-31 (2009). For instance, they spell out Pauls' method of proof for the existence of solutions to the n-queens problem (which appears in the first part of the article for which you want the second part):

> **Theorem (Pauls 1874).** For all n\>3, n non-attacking queens can be placed on the n x n standard chessboard.

The Bell--Stevens paper does point out that Pauls' part II gives a proof that the 92 solutions to the 8-queens problem given in 1850 by Nauck are exhaustive. But unfortunately, Pauls' method of proof isn't given. (That said, Pauls' work here is mentioned alongside Gauss' earlier claim that a brute force computation could be used to prove that 92 is the total number, so perhaps that gives a hint at how Pauls proceeds.)

**Edited to add:** Bell and Stevens do point to two other old secondary sources which they say offer "excellent summaries" of prior work done on the 8-queens problem. These are:

1. E. Lucas, *Récréations mathématiques*. 2ième éd., nouveau tirage. Librairie Scientifique et Technique Albert Blanchard, Paris, 1973.
2. T.B. Sprague, On the eight queens problem, *Proc. Edinburgh Math. Soc.*, 17 (1899), pp. 43–68.

The first is available online via Gallica (see the section on "Le problème des huit reines"), but it appears not to discuss the work of Pauls; rather, it focuses on the work of Günther (S. Günther, Zur mathematischen Theorie des Schachbretts, *Arch. Math. Phys.*, 56 (3) (1874), pp. 281–292), which work also receives an English-language exposition in an 1874 *Philosophical Magazine* article by Glaisher.

The Sprague piece is also available online, via Google Books, but sadly it doesn't address Pauls either; instead, it again offers a look more at the Günther/Glaisher work, but this does at least mean explicitly addressing the matter of the 92 8-queens solutions on the standard chessboard, among other things.
> 8 votes

# Answer
For people stumbling on this question: volume 29 is available online though Google Books since februari 2015.
> 6 votes

---
Tags: history, chessboards, mathematics
---


# Question
Title: Women in Chess - First women-only event.
What was the first women-only event held in Chess history?

# Answer
> 7 votes
The *First International Ladies' Chess Congress* in London, 1897. Games commenced on June 23 and the tournament was finished on July 3. It was organized by the Ladies' Chess Club of London and the Women's Chess Club of New York. The time control was 20 moves per hour, from 1 to 5 pm and 7 to 11 pm. Two games were played per day.

Results (after 19 rounds):

1. Mary Rudge 18.5
2. Louisa Matilda Fagan 15.5
3. Eliza Mary Thorold 14
4. Harriet J. Worrall 13
5. Marie Bonnefin 12.5
6. F. Sterling Barry, Edith Margaret Thomas 11.5
7. Gertrude Field 11
8. G. Watson, A. M. Gooding 10.5
9. E. H. Sidney, Alice E. Hooke 10
10. Rita Fox 9
11. Anna Hertzsch 8.5
12. Eschwege 6
13. Müller-Härtung 5.5
14. De la Vigne, Forbes-Sharpe 4
15. Finn 3.5
16. Stevenson 1

Referee: Harry Nelson Pillsbury

My sources are

* Batgirl: *Women Can Play Chess!*, 2013, chess.com
* Joost van Winsen: *The Ladies Made an International Move*, 2016, chess archaeology (with many pictures!)

# Answer
> 5 votes
The first women's world chess championship was held in London in 1927 and won by Vera Menchik (who successfully defended her title until she died during the Second World War). The WWCC was organized by FIDE in 1924.

There doesn't seem to be any record of a women-only tournament before that time.

---
Tags: history
---


# Question
Title: What is the origin/history of the traditional piece values?
Almost everyone knows the standard rules of thumb: a minor piece is worth three pawns, a rook is worth five pawns, and a queen is worth nine. (I’m aware that this is debated; in particular many theorists think the exchange is worth less than two pawns, but at any rate this is the most famous and well known set of values).

When were these consensus material values first stated? Who came up with them, and how?

# Answer
> 15 votes
In Claude Shannon's paper of 1949, he quotes those values as part of his evaluation function:

> Most of the maxims and principles of correct play are really assertions about evaluating positions, for example: -
>
> (1) The relative values of queen, rook, bishop, knight and pawn are about 9, 5, 3, 3, 1, respectively. Thus other things being equal (!) if we add the numbers of pieces for the two sides with these coefficients, the side with the largest total has the better position.
>
> (2) Rooks should be placed on open files. This is part of a more general principle that the side with the greater mobility, other things equal, has the better game.
>
> (3) Backward, isolated and doubled pawns are weak.
>
> (4) An exposed king is a weakness (until the end game).
>
> These and similar principles are only generalizations from empirical evidence of numerous games, and only have a kind of statistical validity. Probably any chess principle can be contradicted by particular counter examples. However, form these principles one can construct a crude evaluation function. The following is an example: -
>
> `f(P) = 200(K-K') + 9(Q-Q') + 5(R-R') + 3(B-B'+N-N') + (P-P')
>  - 0.5(D-D'+S-S'+I-I') + 0.1(M-M') + ...`

He doesn't cite an explicit reference for these values, but appears to treat them as well-known. He does cite three obviously chess-related books published from 1937 onwards.

However, Nimzowitsch's *My System* was first published in 1925, and it is not immediately obvious that specific relative values are assigned to pieces; a text search for "piece value" yields only oblique references to the idea that a rook is so much more valuable than a pawn that the former should not be tied down to defend the latter. With that said, *My System* is a textbook about positional play, so could be said to have moved beyond simple material analysis.

Also first published in 1925 was *Lasker's Manual of Chess*, which starts from the very basics - the form of the board and the rules of moving pieces. Here, we *do* find a numerical description of piece value, near the end of the "first book":

> We rivet our attention on the games of the experienced \[…\] and among them certain regularities show very plainly. \[…\] Hence, we know that *ceteris paribus* (all else being equal) knight and bishop are even, either is *ceteris paribus* worth three pawns, rook *ceteris paribus* as strong as knight or bishop and two pawns, queen very nearly as strong as two rooks or three minor pieces.

From this prose, we can extract B=N=3, R=5, Q is a little less than 10 (2xR) or 9 (3xB/N).

He then goes on to point out some situations where the qualification *ceteris paribus* is most definitely *not* true. But again, it is not immediately clear from the text whether Lasker was the first to explicitly write these values down, or whether he himself learned them from elsewhere.

A subsequent answer notes that Staunton published a similar set of values in 1847, but essentially quotes Q=10 instead of Shannon's value of 9; these values in turn appear to have been established even earlier. So we can see that Lasker may have obtained these piece values from Staunton (a very influential figure in chess, so Lasker would certainly have read him) and, before writing his own chess manual three-quarters of a century later, revised them based on his own experience.

It appears that Lasker revised his own values yet again for a later 1947 work, to values somewhat different from Shannon's: B=N=3.5, R=5, Q=8.5.

It is also worth noting that modern chess engines sometimes choose a different set of values entirely, especially when they are self-optimised. Stockfish uses N=4.16, B=4.41, R=6.625, Q=12.92, which roughly corresponds to devaluing an individual pawn more than anything else. Nevertheless, the "standard" values appear to have remained reasonably stable through the late 19th century and most of the 20th.

# Answer
> 5 votes
**Before 1847**

The value of the chess pieces was established in the XIXth century. The simple scheme 1-3-3-5-10 (rather than 9 which is common nowadays) was already accepted in the first half of the century (and maybe introduced even earlier, we gotta check Philidor, Stamma or even the Italian school).

I was surprised I couldn't find any reference to it in Bilguier & Von der Lasa's *Schach Handbuch*, published in 1853 and the main reference for decades - but maybe I haven't checked the right pages. *Edit*: Indeed, @A.Thulin found the value of the pieces in the *Handbuch* and mentioned it in a comment.

Anyway, Howard Staunton gave values to each chess piece in his own Chessplayer's handbook published in **1847**. As you can check on page 34, the short 4th chapter is entitled *On the relative value of the chess pieces* and offers these very sophisticated numbers:

> Pawn 1.00
>
> Knight 3.05
>
> Bishop 3.50
>
> Rook 5.48
>
> Queen 9.94

While Staunton admits that the precision of these values should not be exaggerated, it is obvious from his comments that many writers had already offered their own estimates beforehand. Most of the chess knowledge before Staunton spread through newspapers, so that might be where the first quantitative estimation of the value of the chess pieces originated.

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Tags: history, point-value
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# Question
Title: Collecting principal variations during search and using them in ordering?
In an Alpha Beta search in that utilizes a Negamax framework, how does one collect principal variations to use in move ordering, and how does one use them, without using a transposition table?

Additionally, would it be different in a principal variation search, and do we collect and store important moves for quiescence search too? Please provide a code example.

# Answer
> 1 votes
> In an Alpha Beta search in that utilizes a Negamax framework, how does one collect principal variations to use in move ordering

Every strong modern chess engine which uses alpha-beta search uses a transposition table to store the PV move for ordering. If you are writing a chess engine, you should this high-performance, now ubiquitous technique.

> and how does one use them, without using a transposition table?

There are various approaches to storing the principal variation which are commonly used *alongside* a transposition table. The most popular of these is a triangular PV table. The Chess Programming Wiki has a page on this, which includes code examples as you requested.

> Additionally, would it be different in a principal variation search

No. Move ordering can be implemented in the same way for both pure alpha-beta and for PVS. The only difference is the way in which the ordered moves are searched.

> and do we collect and store important moves for quiescence search too?

No. Standard techniques used to order captures are sufficient in quiescence search (namely, MVV/LVA and Static Exchange Evaluation). The move stored in the transposition table may not be a capture, so it is unlikely to be useful for quiescence.

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Tags: engines, programming
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