# Question
Title: Elo disadvantage due to one pawn move in Indian Chess
In Indian chess, the pawn doesn't move two squares, however in the western chess, pawn can move two squares. Now, since the pawn can't move 2 in the Indian style, the fianchetto is a natural square to develop your bishops.

So for a player like Sultan Khan playing against other chess players from West, what kind of an Elo disadvantage would that put him? How does one estimate such a number?

Suppose one puts a constraint like this in Stockfish and lets it play against another Stockfish and observe how it does in a million games - would that be an acceptable way to estimate disadvantage?

# Answer
> 12 votes
Revised stockfish to skip searching double pawn push. Each engine is using 2 threads at TC 1m+1s. It got 4 draws in 20 games.

### Test 1

`sf_no_pawnpush4` is not aware that its opponent can play a double step pawn push and `sf_normal` is not aware that its opponent can only play a single step pawn push.

```
Score of sf_no_pawnpush4 vs sf_normal: 0 - 16 - 4 [0.100]
...      sf_no_pawnpush4 playing White: 0 - 7 - 3  [0.150] 10
...      sf_no_pawnpush4 playing Black: 0 - 9 - 1  [0.050] 10
...      White vs Black: 9 - 7 - 4  [0.550] 20
Elo difference: -381.7 +/- 252.4, LOS: 0.0 %, DrawRatio: 20.0 %
20 of 20 games finished.

```

Sample games:
https://lichess.org/UVMYm3Tf#6
https://lichess.org/sBp98pXn#84

### Test 2

Each engine is aware of its opponent's capabilities.

```
Score of sf_no_pawnpush4_aware vs sf_normal_aware: 0 - 19 - 1 [0.025]
...      sf_no_pawnpush4_aware playing White: 0 - 10 - 0  [0.000] 10
...      sf_no_pawnpush4_aware playing Black: 0 - 9 - 1  [0.050] 10
...      White vs Black: 9 - 10 - 1  [0.475] 20
Elo difference: -636.4 +/- nan, LOS: 0.0 %, DrawRatio: 5.0 %
20 of 20 games finished.

```

Sample games:
https://lichess.org/l86RNFcn
https://lichess.org/A67hMP3i

---
Tags: opening, history, tactics, chess-variants, elo
---


title: Can Black draw this game?

text:
# Question
Title: Can Black draw this game?
Carlsen-Svidler 2010 Blitz. Black to move. Can he draw by perpetual checks? In the actual game, he resigned two moves later.

```
[FEN "6R1/8/3B4/5K1k/r7/8/8/8 b - - 0 1"]
[StartFlipped "0"]

```

# Answer
Perpetual check is out of the question (after Ra5+ Be5 the only check is Rxe5+ but that loses quickly) but this endgame has some other drawing techniques: stalemate and exchanging rooks. However, according to endgame databases Black is losing (their rook) in 13 moves and will be mated shortly after. It is very reminiscent of the Philidor position, especially after the 2nd move by White listed there. The white pieces dominate the Black rook and it is soon out of tricks.
> 3 votes

---
Tags: endgame, draw, blitz, carlsen, rook-and-minor-endgame
---


title: Piece values on nonstandard boards

text:
# Question
Title: Piece values on nonstandard boards
Inspiration.

For the moment, a nonstandard nxn board suffices. Very obviously, with growing n the long-range pieces become stronger with respect to short range ones. (Also, other effects come in play, e.g. the Q can't regularly win against a R if n is large enough.) Does any research on assigning piece values on a nonstandard nxn board exist?

# Answer
Here is one idea.

1. Create an engine that can play on that nxn board.
2. Expose the piece value as option for tuning.
3. Conduct piece value optimization using optuna hyperparameter optimization framework or other framework. Typical example is the optuna game parameter tuner.

After some trials you will be able to get a decent piece values.
> 3 votes

---
Tags: chess-variants, point-value, reference-request
---


# Question
Title: Python Efficient Board Scoring Function To Use As Placeholder
I'm building a chess engine in Python. I'd like to find a board evaluation function that would be easy to put into my engine as a placeholder while I work on other aspects of the engine first.

I would love to use some iteration of StockFish's board evaluation. But there's no way I can see to do this without interacting with the normal StockFish engine in some way that has obscene overhead.

So, basically, I'm wondering if there are any evaluation functions someone else has already made that I can use. I would like for it to be easy to get working, not *extremely* slow, and not that bad at scoring boards.

Bonus points if possible:

* The board representation it expects is a Python-Chess `Board` object (or uses similar bitboards)
* You also know of a placeholder I can use for move ordering as well (would have the same criteria as the evaluation function)
* It's actually written fully in Python, so JIT compilation may be possible (so NumPy works but not much else)

# Answer
A simple board material evaluation using python-chess.

#### Code

```
import chess

PV = {
    'pawn': 100,
    'knight': 320,
    'bishop': 330,
    'rook': 500,
    'queen': 950
}

DRAW_VALUE = 0

def evaluation(board):
    if board.is_insufficient_material():
        return DRAW_VALUE

    wp = len(board.pieces(chess.PAWN, chess.WHITE))
    bp = len(board.pieces(chess.PAWN, chess.BLACK))

    wn = len(board.pieces(chess.KNIGHT, chess.WHITE))
    bn = len(board.pieces(chess.KNIGHT, chess.BLACK))

    wb = len(board.pieces(chess.BISHOP, chess.WHITE))
    bb = len(board.pieces(chess.BISHOP, chess.BLACK))

    wr = len(board.pieces(chess.ROOK, chess.WHITE))
    br = len(board.pieces(chess.ROOK, chess.BLACK))

    wq = len(board.pieces(chess.QUEEN, chess.WHITE))
    bq = len(board.pieces(chess.QUEEN, chess.BLACK))

    value = (
        PV['pawn'] * (wp - bp) +
        PV['knight'] * (wn - bn) +
        PV['bishop'] * (wb - bb) +
        PV['rook'] * (wr - br) +
        PV['queen'] * (wq - bq)
    )

    if board.turn == chess.WHITE:
        return value
    return -value

# Start
fen = 'rnbqkbnr/ppp1pppp/8/3P4/8/8/PPPP1PPP/RNBQKBNR b KQkq - 0 2'
board = chess.Board(fen)
print(board)

value = evaluation(board)
print(f'board evaluation: {value}')

```

#### Output

```
r n b q k b n r
p p p . p p p p
. . . . . . . .
. . . P . . . .
. . . . . . . .
. . . . . . . .
P P P P . P P P
R N B Q K B N R
board evaluation: -100

```
> 2 votes

# Answer
The usually basic evaluation people will start off with consistent material balance and piece-square tables. The material balance makes sure the engine understands basic ideas of trading and tactics, while the piece-square tables make sure the engine plays reasonable chess and encourages ideas like pushing pawns in the endgame or centralizing knights.

It honestly shouldn't be too hard to role your own code. For example, here's what my evaluation function looked like for a while, in Golang.

Another example of a simple implementation is PeSTO, which does include one more feature known as tapered evaluation, which sounds like a fancy idea but is really just based on the intuition that different things become important going from the middle to endgame. In the middlegame the king should hide away to avoid getting mated, but in the endgame the centralization of the king is crucial to winning.

Once you come back to the evaluation, then you can focus on adding other important terms like mobility, king safety, and pawn structure (passed pawns, doubled pawns, isolated pawns, etc.)

If your program does use the above-linked PeSTO code verbatim and you make it public (which I hope you would eventually), just make sure you give a little shoutout to where you got it from.

As for the move ordering, that also shouldn't be super hard either. Start with some basic scheme like sorting captures, and then eventually using a transposition table to put the hash move first. This is what Something like that, though a tad more complicated, is what I've done for my engine. See `scoreMoves` and `orderMoves`.

Best of luck.

P.S: http://talkchess.com/forum3/index.php is a great resource for interacting with people who are very knowledgeable and helpful when it comes to building an engine. Consider making an account some time.
> 0 votes

---
Tags: engines, stockfish, evaluation, python
---


title: Memorizing the board

text:
# Question
Title: Memorizing the board
I'm always experiencing difficulties while trying to visualize what moves a tutorial (or an answer here for that matter) is talking about unless I have a chessboard with coordinates nearby.

Is this something I should fix, or is it fine to be using a chessboard? and what can you advise someone who want to memorize it?

# Answer
> 14 votes
The easiest way to visualize the board is to practice! I know that sounds trite, but there aren't really all that many shortcuts. Go over games in magazines. Start from one of the positions given as an image and then "make" as many moves as you can in your head. Try to see the position and look for the threats and ideas of each move. If you can only make one move, that's fine - it's a good start.

Similarly, you can use a physical board when you're going over a game. Play out the moves on the board and start to learn the squares by name as opposed to figuring out which square is which each time. That's probably the first step. After you know the "names" of the squares, the rest will start to fall into place.

# Answer
> 8 votes
There are books available that promise to directly improve your visualisation skills (like "Chess Visualization Course" by Ian Anderson, which I haven't read myself).

But the easiest way to improve your visualization skill that might even make you a better player in more regards is: **Reading tactics books** (like "1001 Winning Chess Sacrifices and Combinations" by Fred Reinfeld). Trying to find the solution without the help of the board is a great way to learn thinking ahead. A great introductionary book to start with (beginning with 1-move-mates) is "Chess: 5334 Problems, Combinations, and Games" by Laszlo Polgar). This way you have tons of material to practice your visualization and hone your tactical prowess at the same time!

# Answer
> 6 votes
On Chess.com you can use the mobile app, then click the three bars (menu) and then click 'vision'; this is basically a game where you look at blank board and it says 'g8' then you hit g8 with your thumb then it goes 'c3'etc etc. You are doing this against time you get a score and all at the end of the time but it does help memorizing the spaces, I've found. After you know the board the pieces algebra comes easier.

# Answer
> 2 votes
Rather than relying on any one suggestion you might want to do a bit of them all. A good start is being able, after you are given the name of a square, to say without hesitation what color it is. To make things more precise, it helps to recall, for example, that b5 is the square that the Lopez bishop goes to. What other squares are important in your favorite openings?

# Answer
> 1 votes
I'm an Android user so I can only speak of Androids but there are chess memorization mobile apps. https://play.google.com/store/search?q=chess%20board%20memorization&c=apps&hl=en

I would guess that there are apps for Apple as well that are similar if you are a Apple user. I just don't have a way to give you search results since I'm not a Mac user.

# Answer
> 1 votes
http://chesseye.alexander-fleischer.de/ has a training tool just for this purpose.

# Answer
> 1 votes
Of course practicing helps, just like in any sport, but there are also TECHNIQUES that make any skill easier to do correctly or to improve more quickly.

At each move or whenever the board is not completely clear, say these words:

"Fix the board in my mind: King is there/F8, my Queen is there/H7, that/G8 is empty, that/D3 is empty".

Don't let naming the squares get in the way of visualization -- both are useful, but practice naming and finding the squares separately -- especially if naming them isn't completely easy or interferes with SEEING in your mind.

It's fine to name them if you can do so fluidly, otherwise merely say "there" and "that" or "next to Pawn"

Generally avoid mentioning pieces that are gone; captured pieces are covered by EMPTY and saying where active pieces are NOW located.

Do include "EMPTY" in your list, both to see open lines and to firmly fix where pieces can now move, as well as to stop "interference" from the real/computer board with the one in your mind.

This is NOT as good as eventually being able to "just do it" but it's a technique anyone can do IMMEDIATELY, even a beginner, to improve right now and work towards better visualization through automatic methods.

With this method, you can continue to look at the actual (or computer) board and just update empty squares and pieces standing on new squares of the BOARD IN YOUR MIND.

At any stage or whenever needed, repeat the process to update the board in your mind -- just doing the process will increase your future ability to visualize, along with clarifying the current board.

A beginner may need to do this after each full move, or even after each half-move at first, while someone with a bit more skill may do it only every 2, 3, or more moves.

Just repeat it as necessary, or use it whenever vision isn't as clear as you wish it to be.

---
Tags: memorization
---


# Question
Title: How to import a game into XBoard from the command line
Is it possible to import a game into XBoard from the command line? I am unable to find anything on it on the XBoard website or the XBoard man page, although I may have missed something.

# Answer
> 3 votes
The manual seems to suggest you can use `-lgf` followed by the name of a PGN file:

```
4.5 Load and Save options
=========================

-lgf or -loadGameFile file
-lgi or -loadGameIndex index
     If the `loadGameFile' option is set, XBoard loads the specified
     game file at startup. The file name `-' specifies the standard
     input. If there is more than one game in the file, XBoard pops up
     a menu of the available games, with entries based on their PGN
     (Portable Game Notation) tags.  If the `loadGameIndex' option is
     set to `N', the menu is suppressed and the N th game found in the
     file is loaded immediately.  The menu is also suppressed if
     `matchMode' is enabled or if the game file is a pipe; in these
     cases the first game in the file is loaded immediately.  Use the
     `pxboard' shell script provided with XBoard if you want to pipe in
     files containing multiple games and still see the menu.  If the
     loadGameIndex specifies an index -1, this triggers auto-increment
     of the index in `matchMode', which means that after every game the
     index is incremented by one, causing each game of the match to be
     played from the next game in the file. Similarly, specifying an
     index value of -2 causes the index to be incremented every two
     games, so that each game in the file is used twice (with reversed
     colors).  The `rewindIndex' option causes the index to be reset to
     the first game of the file when it has reached a specified value.

```

---
Tags: software
---


# Question
Title: Game drawn - timeout vs insufficient material
I just finished a game where I only have a black king and my opponent has a king and a pawn.

My opponent was out of time, and Chess.com considered this was a draw.

> Game drawn - timeout vs insufficient material

This pawn could have been promoted to a queen. Moreover, the pawn was close enough to its king so that I could never capture it with my only king.

Why is Chess.com considering this is insufficient material ? If my opponent is out of time but has the complete potential to mate me, I don't understand why this would be a draw.

```
[FEN "8/5K2/7k/8/8/6P1/8/8 w - - 0 65"]
[StartFlipped "0"]

```

# Answer
> 5 votes
It's pretty simple: your opponent times out, so he doesn't get an opportunity to play on (so, no chance to mate you). If you have any chance of mating him (on the board, given *you* have not run out of time), you'd be given the win. But because you don't have any chance of mating him - as you have "insufficient material"\* - you don't get to win either.

This is considered a drawing condition in chess.

Think of it as: if the game ends because your opponent times out, the result is the most optimistic outcome possible for you given your position on the board. If you can say "this and this might have happened" and led to you winning, then you win. You cannot argue that here as no move sequence delivers mate with a lone King. The best possible outcome for you had the game continued is still a draw.

\*Strictly speaking FIDE (unlike chess servers which need a simple heuristic like material count to go on) does not just do a material count to determine the winner. The question to be answered is "is there any sequence of moves by which a mate can be delivered by player X?" and this is answered in the problemists' style, i.e. with no regard for how reasonable it is to expect player Y to play along with that sequence. But in practice it doesn't matter here since with a lone King you (player X) obviously cannot mate your opponent (player Y).

---
Tags: draw
---


# Question
Title: Why are some chess championships defended while others have the champion starting from scratch?
For example, the World Chess Championship as of the past few cycles had a candidates tournament to determine who faces the previous champion. Same with the Women's World Chess Championship (at least as of recently).

These are unlike other championships like say World Blitz, World Rapid, US Chess Championship, British Chess Championship, the women's versions of the preceding and the Women's World Chess Championship (until recently). In these latter cases, the champions start from scratch, so I find it weird to say Wesley So successfully 'defended' the US Chess Championship in 2021 or that Jovanka Houska didn't 'defend' the British Women's Chess Championship in 2021.

I don't even see why they are **called championships in the 1st place instead of just 'tournaments'** like say the Grand Chess Tour or Tata Steel. So, I don't see why we are calling MVL the 'current' world blitz 'champion' instead of the 'most recent' World Blitz 'winner'.

Or alternatively, I don't even see why we don't call Wesley So the 'current' Grand Chess Tour 'champion' instead of the most recent grand chess tour 'winner'.

**Guess**: A championship, as opposed to merely a tournament, implies some kind of 'representation'.

By representation, I mean representing

* a country like the US or the Philippines or the Commonwealth of Nations,
* all of chess,
* all of women's chess,
* all of blitz chess,
* all of women's rapid chess, or
* all of 960 (at least in slow rapid and lower time formats).
But there's no representation meant by 'Grand Chess' or 'Tata Steel'.

Note 1: I'm not familiar with sports/gaming in general, so perhaps this can be or is answered by how sports/gaming in general work. You can answer chess-specific or generally.

Note 2: I guess we exclude talking about cases where we have to determine an inaugural champion, like say the inaugural FIDE World 960 Championship in 2019. Also, I guess determining a new champion if the old champion forfeits.

# Answer
> Why are some chess championships defended while others have the champion starting from scratch?

The simple answer is "History". The open chess world championship predates FIDE by many years and was already established as somehow the "property" of the current holder. To challenge the holder you had to be a good player, not necessarily the best of the challengers, and to have enough money to bet against the holder.

This tradition was not just a chess tradition. It came from martial arts like boxing which had pretty much the same sort of structure.

FIDE inherited this structure, as it were, and just continued it. When a women's world championship was instituted in the interests of women's equality this tradition was carried over to the women.

However in titles like U18 world champion it just makes no sense. The winner of the U18 championships 2 years ago often no longer qualifies because he or she is now over 18.

When it comes to continental and national championships there is not the same tradition as the open world championship. These have evolved in a fairer way with all-play-alls for smaller fields with pre-selection or the more modern Swiss style tournaments which allow much bigger fields.

That a round robin tournament is the fairest way of finding the best player is now more widely accepted. That is the way the candidates tournament is run to select the challenger for the world champion. It wasn't always so. When Fischer qualified to play Spassky in 1972 he did so the hard way by winning a short series of knockout candidate matches.
> 5 votes

---
Tags: history, world-championship, candidates
---


# Question
Title: Chess players with FM, IM or GM, starting career after 40?
I started my chess career very late. I knew precise knowledge about Chess at age 41. The first tournament I shared was when I 42 years old; I got performance rating of 1050.

Could you give me hope?

I'd like names of 5 FM, 3 IM and 2 GM who started their career after 40.

# Answer
> 7 votes
Here are the list when they get their title after 40 years old.

* Download the fide rating file
* Get the player id
* Scrape fide website profile page using id to get the year the title was awarded.
* If title\_year - birthyear \>= 41, save the player.

```
{'id': '34145670', 'name': 'Afanasev, Sergei Gl', 'title': 'FM', 'birthyear': 1958, 'title_year': 2013}
{'id': '4637909', 'name': 'Abel, Thomas', 'title': 'FM', 'birthyear': 1968, 'title_year': 2020}
{'id': '4142713', 'name': 'Abramov, Leonid', 'title': 'FM', 'birthyear': 1971, 'title_year': 2015}
{'id': '2200937', 'name': 'Acebal Muniz, Antonio', 'title': 'FM', 'birthyear': 1964, 'title_year': 2007}
{'id': '2200546', 'name': 'Acebal Muniz, Jose Maria', 'title': 'FM', 'birthyear': 1965, 'title_year': 2007}
{'id': '401137', 'name': 'Adams, James B', 'title': 'FM', 'birthyear': 1947, 'title_year': 2014}

{'id': '1101439', 'name': 'Adamski, Andrzej', 'title': 'IM', 'birthyear': 1939, 'title_year': 1980}
{'id': '1701991', 'name': 'Aaberg, Anton', 'title': 'IM', 'birthyear': 1972, 'title_year': 2013}
{'id': '701424', 'name': 'Abel, Lajos', 'title': 'IM', 'birthyear': 1944, 'title_year': 1989}
{'id': '10600078', 'name': 'Abou El Zein, Eid Mahmoud', 'title': 'IM', 'birthyear': 1952, 'title_year': 1993}
{'id': '4144970', 'name': 'Abramov, Boris', 'title': 'IM', 'birthyear': 1941, 'title_year': 2001}
{'id': '2603896', 'name': 'Adam, Valerian', 'title': 'IM', 'birthyear': 1937, 'title_year': 2009}

{'id': '12501000', 'name': 'Abbasifar, Hasan', 'title': 'GM', 'birthyear': 1972, 'title_year': 2013}
{'id': '4120612', 'name': 'Alavkin, Arseny', 'title': 'GM', 'birthyear': 1969, 'title_year': 2010}

```

# Answer
> 4 votes
> Chess players with FM, IM or GM, starting career after 40?

The answer is "None".

There are a few players who get the title after the age of 40 but none who get the title after starting after the age of 40.

> The first tournament I shared was when I 42 years old; I got performance rating of 1050.
>
> Could you give me hope?

No. You are never going to be a FM. You may, however, like the vast majority of us enjoy a game which can give much pleasure without reaching master level.

Reaching 2300 level is very difficult even if you start when you are young. I checked on my database, constructed from Olimpbase and FIDE rating data, for players with a minimum rating below 1100 and a maximum rating above 2300 and got just 5 players, all of them children. Note that I think FIDE only lowered the rating floor to 1000 in 2012.

**FullName FIDEID DoBYear MinR MaxR**
Juhasz, Agoston 778346 **2005** 1055 2386
Martin Barcelo, Carles 24561444 **2004** 1013 2315
Manish Anto Cristiano F 25095927 **2005** 1087 2383
Bharath Subramaniyam H 46634827 **2007** 1009 2479
Sreyas Payyappat 46674969 **2008** 1010 2303

---
Tags: history, titles
---


# Question
Title: Can the "bishop pair advantage" be supported by statistics?
I heard a lot about the advantage of having a bishop pair and I am interested in the statistics about this. More specifically, if we collect a huge number of games (master games only, or games including non-titled players) for which at any point of the game, one side has exactly two bishops as his/her only minor pieces and his/her opponent has exactly two knights (or N+B) as his/her only minor pieces, what is the winning percentage?

I will be interested in the winning percentage of:

1. BB vs NB
2. BB vs NN
3. NB vs NN.

**Edit** I know this is extremely rare; but what will happen to the winning percentage for BB vs NB and BB vs NN if the two bishops are of the same colour? (Here is a related question.)

# Answer
> 13 votes
* Download all games from top players. Around 341k games excluding the duplicates.
* Use pgn-extract to get BBvNB, BBvNN and BNvNN games.
* Run bayeselo to get the stats.

## Results

##### Table 1

```
Rank Name:   Elo    +    - games score oppo. draws   win  loss  draw
   1 BB  :    29    2    3 67811   55%     0   37% 24402 18049 25360
   2 NB  :     0    3    2 67811   45%    29   37% 18049 24402 25360

```

##### Table 2

```
Rank Name:   Elo    +    - games score oppo. draws   win  loss  draw
   1 BB  :    37    3    4  9896   56%     0   31%  3990  2873  3033
   2 NN  :     0    4    3  9896   44%    37   31%  2873  3990  3033

```

##### Table 3

```
Rank Name:   Elo    +    -  games  score oppo.  draws   win  loss  draw
   1 NN  :     3    4    4  31993  50.4%     0  35.7% 10421 10160 11412
   2 NB  :     0    4    4  31993  49.6%     3  35.7% 10160 10421 11412

```

The elo leads are significant for table 1 and 2. For table 3 the elo advantage is still within the error margins.

---
Tags: statistics, knights, bishops, bishop-pair
---


# Question
Title: How to find only-winning moves in the endgame?
**Black to move here.**

I played 1... Rf5. Intending to cut off the king.

But the only winning move in this position is e5.

My question is, how do you find such a move? Is it pure calculation, or is it some general principle, that I missed in this case? What is the method of solving these kinds of positions?

Currently rated 1650 on chess.com

Check out the game:https://www.chess.com/a/2UsLVrAfGjcDc

Move 53.

# Answer
A toughy and a great example of the intrinsic value of studies at home and then reproducing over the board.

One crucial line after e5 involves checking from g1, forcing the king to the h-file where it's open for a mate, and once Kh5 is played, giving you the option to play pawn to e4, unprotected, but poisoned since you escape check with Kf5! in a way that attacks whites rook and threatens mate next move with Rh1#.

That's some pattern recognition for you, else good luck finding that motive over the board (OTB). To my (1900ish) best OTB advice: it is asking myself questions.

* In the given position, what's my plan to evade checks from the queenside?
* While cutting off whites king looks superb, there is no need to hurry, so are there moves that make progress and leave myself the option to cut off later?
* Is there a way for my opponent to bring his king behind my passer?
* How am I stopping their plan?
* Also, since pushing a passer should always rank among my first candidate moves: can I find a line for my opponent to outright win the pawn or at least stop its advancing further, granting tempi to consolidate (see above, king behind passer)?

That being said, Rf5 was my instinct move as well.
> 3 votes

# Answer
And here we have those who have read tons of endgame books (me) and everyone else (you) - just kidding. Also, I had the general theme in a training session as a kid and thus know by heart. But I can explain everything from general principles.

1. The white king *is* already cut off! I think Karsten Müller highlighted that we tend to overlook a horizontal cut off, and that it is even worse than a vertical.
2. That said, Rf5 is so bad that you can have a black extra move - none wins!
3. The minimum checking distance for a R: If the pawn is on e5, the distance may be already too short (depending on whether the bR protects it). If it is on e4, and the wK cut off, the bR doesn't even have to bother, K and P just march - try it out!
4. Sorry, starrin, but the mating motive you mention is unadulterated red herring :-) You can verify by moving all pieces one to the right. No more mates, but suddenly (almost) every move of Black wins!
5. White to move would lose with Kg6, but Kh6 is OK (wat?), Re3 draws (I play that without thinking, and Rg4 (son of wat???) is the third drawing move. Here is some fun variant: 1.Kh6 Rd8 2.Ra3 Rg8 (got you cornered, ha!) 3.Ra1 e5 (triumph, go play Re1 and again the distance is too short) 4.Ra6!! (neener neener, two can cut off!)
6. I only got a hunch why moving everything to the right drastically changes the position - now the *side* is too short for White to give safe R checks! I made rather silly looking draw moves for White and came to Kg3 Ra3 - Ke2 Rf1 Pe3, still White is cut off, still no way for Black to win as the Ra3 is exactly far away enough. (Rb3 Ra1, win)

It is very enlightening to experiment with the position and a tablebase.
> 3 votes

---
Tags: endgame, rook-endgame
---


# Question
Title: Looking for free versions of older chess engines
In connection with another project, I am looking on the internet for some free versions of older chess engines, such as some of the old Chessmaster engines from the 1990s. I would even take an old Fritz engine if there were one.

I'm wanting to compare older chess engine output to modern chess engine output. I'm aware that engines like Stockfish are far superior in playing strength than anything made in the 1990s.

# Answer
Fritz 5.32 (I'm guessing the first 32 bit version) dates from about 20 years ago, I think. That is available for download via the wayback machine here. Note that you will probably need to install it in compatibility mode as Windows 98/ME on Windows 7. Not sure if you can do this on Win 10.

The oldest version of Crafty I could find, another old favourite, was 8.11 download here.

Chessmaster 8000, another Windows 98/ME program is available for download on this website.

Finally, if you can run a DOS box emulator then all the way back from 1990 is version 3.1 of GNUChess from this website. 181 kb (!) zip file here.
> 13 votes

# Answer
The other excellent answer by Brian Towers ♦ provides individual perhaps-ideal direct links, but you may see further benefit from your own search on The Internet Archive (https://archive.org) which has a vast collection of ancient (ha) software, including some chess software

A query like this may be all you need to get at them
https://archive.org/details/software?query=chess&and\[\]=subject%3A%22chess%22

The oldest engine I could find via that query is MyChess, and you can just step by-years with a filter at the left

> MYCHESS is one of the oldest chess games ever made. It was developed by David Kittinger (the man behind the famous Chessmaster games) in 1979, although the DOS version was published in 1984.

https://archive.org/details/mychess
> 3 votes

# Answer
The Internet Archive has lots of browser-playable Chess games:

https://archive.org/details/softwarelibrary\_msdos\_games?query=chess&sort=-downloads
> 2 votes

# Answer
Ed Schröder has made a pretty sizable collection of old chess software (including the code from some old dedicated chess computers, turned into UCI engines) on his web site for free download. Look in the sections labelled "OLD", "REBEL13", and "DEDICATED -\> DEDICATED AS UCI".
> 2 votes

---
Tags: engines, history
---


# Question
Title: Relation between ratings for Chess960 and standard chess
Is there any relation or any attempt at discovering a relation between Chess960 ratings and standard chess ratings? This can be for GMs, for (any)M's, for pro players, or for all players on lichess/chess.com (for whatever lichess/chess.com statistics are available), but preferably for as many categories/divisions/what you call it as possible.

I'm looking for something similar to this reddit post: I made a website to compare chess ratings between Chess.com, LiChess, FIDE, & USCF. This way 1 might see eg 9LX ratings on lichess are about 100 points less than standard blitz ratings on lichess or 200 points less than standard rapid ratings on lichess.

---

**Something I thought: I guess there's weekly rating distributions**.

For example in the 'week' (whatever this means) of 2021-11-12 13:50:07Z (the time now) 49% is 1575 in 9LX, 50% is 1525 in blitz and 49% is 1525 in rapid. Assuming everyone on lichess plays 9LX, blitz and rapid about the same, I guess this suggests 9LX ratings are about 50 points higher than regular ratings, which of course is not the case.

I guess what would be helpful is seeing the blitz and rapid percentiles conditioned on non-provisional 9LX ratings. Of course there's the lack of time control separation in 9LX ratings. Perhaps we might do some weighted average like if 90% 9LX games are blitz and 10% are rapid then.......idk.

standard:

9LX:

---

Related:

What are some solutions to a possible/perceived underratedness problem in online chess960?

# Answer
Web app called rating correlations is now published in streamlit cloud. It is slow so just be patient, will try to optimize it later.

It can also estimate crazyhouse aside from chess960. Rating data are all from Lichesss.

You can input by double-clicking the number and type your bullet rating for example, the -/+ button is not necessary.

App is updated for performance and source code can be found in github.

Update 1: Can estimate rating based from chess.com users.

url: `https://ratingcorrelations.herokuapp.com`
> 5 votes

---
Tags: rating, chess-variants, statistics, mathematics, chess960
---


# Question
Title: Does it makes sense to have a 1315 Blitz rating and a Rapid rating of 1729?
I am rated 1330 for Blitz on Lichess. I was trounced by a clearly better player who had a lower ranking of 1315 for Blitz. Their profile also shows a Rapid rating of 1729.

Is it possible for these both the Blitz (34 percentile) and Rapid (70 percentile) ratings to be a true reflection of the player's ability? Both ratings are on over 300 games.

# Answer
> 12 votes
On chess.com my ratings are:

* Blitz: 1339
* Rapid: 1721
* Daily: 2153

My understanding of chess doesn't change based on time control. I am poor at quickly performing safety checks and so blunder more at faster time controls.

# Answer
> 4 votes
There are several factors involved with rating differences:

1. There is no one-to-one mapping between blitz and rapid ratings on online sites such as lichess and chess.com. Usually, the blitz pool has much more experienced and stronger players, thus your rating in blitz could be (much) lower. But this is also subject to your actual rating. For example, if your rating is 1200 in blitz, then your rapid rating could be 1600 since lower-rated players in rapid are weaker than blitz pool (with the same rating I mean: 1300 blitz player is usually much stronger than 1300 rapid player). But if your blitz rating is high, e.g., 2600 blitz, then it could be that your rapid rating is not much higher than your blitz since not many high rated players actively play rapid online, thus you don't get a chance to actually increase your rating too much.
2. Many players are good in the middle game but they don't have a good opening knowledge, so at the start they have to think about their moves, and consequently, they are not good at blitz, since there you should be rather quick in the opening.
3. Clearly one other factor is the cheating possibilities. It is much easier to cheat in a rapid game than a blitz match, especially for those who are not good at chess. I'm not playing rapid in lichess so I don't know what is the exact cheating situation there, but for chess.com, I can tell there is a good chance of facing a cheater in a handful of games (at least in my rating bracket).

# Answer
> 3 votes
First of all, offhand I don't see what advantage "differential sandbagging" would bring on Lichess, but then, I never played online. That said, I can come up with much more legit possibilities for person X having a vast rating difference in different modes:

* It's genuine and style-based. I bet my own rating would be vastly higher in Blitz (even with 60 :-), at least 100 points.
* Even on same (OTB tournament) mode, my ELO was constantly 100 points higher than my national rating. This is the influence of the opponents sample (naturally my ELO opponents are far stronger in average), and can be prevalent in this example too.
* Also, in statistic you must ask: On how many games is the rating based? Especially in the weaker echelon, huge "daily" strength fluctuations can occur.
* All kids of my chess club love playing online, and I clicked a bit through their profiles. Already the third also had 400 points difference between blitz and rapid, with around 50 games each. Given that the number of Lichess players is a few orders higher than the number of kids in my chess club (too bad), the probability of a stable 400 point difference caused merely by a statistic fluke skyrockets.
* I know another guy in my chess club, who has (had?) about 1000 rating points less than me and constantly brought me into trouble since he knew openings. Same could happen here, if you start already bad out of the opening, trounceville.
* That said, have you checked the errors of the game with a computer? If, objectively, you constantly handed points back and fro (rather common at 1300), it still can feel like a trounce.

tl;dr: I wouldn't think for a second of any foul play.

# Answer
> 2 votes
My real FIDE Elo was 2400 at max in 199x and in 2018 my real blitz rating was 17xx(Now I got few hundred points back in few tournaments). Not everybody who plays on platforms or even in tournaments have your "professional attitude" and cares about rating - I don't care about my - I play for fun, intentionally go for high risk combinations often loose to 1500-1600 players but at same time when I meet GMs I pretty often beat them or play on equals as that game for me makes sense and I'm concentrating and not playing fake combos just for fun. My online ratings are fluctuating like hell as I often play at work while in boring meetings and just resign when asked question and have to go or sometimes loose stupidly due to double focus! My own top rating on lichess is 23xx and often it falls to 22xx or even 20xx, but at the same time I have a 2400+ player against whom I lead 6:0, because I play those games - they make sense to work for me - if I play you I may easily loose as I don't care - I know I'm better player, nothing to prove.

So only 400 points diff between 2 online ratings and with different time controls - good but slow player. Or may be like me - does not care ratings!

Obviously it can be both - true reflection of players ability to play at certain speeds(lot of old people are just not good with mouse controls for example, so they loose fast games by quickly getting into time trouble) and it can be reflection of players true rating due to careless play or fun attitude!

Players like you who are analyzing his opponent ratings after the game instead of game itself never learn a game itself. If you will not change your attitude you will never learn to play chess!

# Answer
> 2 votes
Check out https://chessgoals.com/rating-comparison/

They have a table showing a Lichess blitz of 1365 generally corresponds with rapid of 1550 +/- 140, so upper bound of 1690 one standard deviation away. This means in their analysis, 16% of Lichess players would have around 1365 blitz and above 1690 rapid.

This is really not a huge difference, and if you were wondering whether they are cheating, 1700 Lichess rapid is pretty low (would be about 1300 USCF).

# Answer
> 1 votes
According to https://www.chessratingcomparison.com/graphs

> A rating of 1315 in LiChess.org: Blitz would equal 1535 in LiChess.org: Rapid, with an average variation of plus/minus of 101 points.

See for yourself

Perhaps you're a little underrated in blitz. Try playing more games maybe?

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


title: Personal chess database

text:
# Question
Title: Personal chess database
I'm looking for non commercial program where I can import PGNs. And to visualize the games I want simple GUI and analysis-table like you will find here. Additionally it would be nice if the program provides an interface where I can write my own statistics.

What I found was gnu chess, sunfish and jose. But those programs are more then I'm looking for.

# Answer
SCID does everything you are looking for, it's great chess database software.
> 7 votes

# Answer
Lichess has everything you need. It also updates a new list every month so the database always grows. Currently it has over 2,000,000,000 games. All in a pgn file. They also publish issues they have recorded to help people resolve their code. One more thing Lichess has is not only standard chess but also variants and puzzles all of which are separate and update monthly.
> 0 votes

---
Tags: software, database, linux
---


# Question
Title: What are some examples of wins by a much weaker player?
I'd like to study examples where a much weaker player succeeded against an IM or GM.

# Answer
This game comes to mind:

It was a first game in a 2 game match of the first round knock out FIDE championship. Anand rated at 2770 was I believe the highest rated player in the event. Touzane, I believe, was not a professional player. Touzane won the first game. Despite the first game win for Touzane, Anand won the second, and then the tie-break. Nevertheless, Anand losing to a player rated 400+ below him was quite a shocker.

```
[FEN ""]
[Event "FIDE WCh KO"]
[Site "Moscow RUS"]
[Date "2001.01.02"]
[EventDate "2001.11.27"]
[Round "1.1"]
[Result "0-1"]
[White "Viswanathan Anand"]
[Black "Olivier Touzane"]
[ECO "C42"]
[WhiteElo "2770"]
[BlackElo "2368"]
[PlyCount "78"]

1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Nc6
7. O-O Be7 8. c4 Nf6 9. Nc3 O-O 10. Re1 Be6 11. cxd5 Nxd5
12. a3 Bf6 13. Be4 h6 14. Bc2 Nxc3 15. bxc3 Bc4 16. Nd2 Bd5
17. Rb1 Bg5 18. c4 Bxd2 19. cxd5 Bxe1 20. dxc6 Ba5 21. Qd3 g6
22. cxb7 Rb8 23. Bxh6 Re8 24. Qf3 Re6 25. Bb3 Rf6 26. Qg4 Rb6
27. Bg5 Qe8 28. Qf3 R8xb7 29. h4 Qd7 30. g4 Rxb3 31. Rxb3 Rxb3
32. Qxb3 Qxg4+ 33. Kf1 Qxd4 34. Be3 Qa1+ 35. Kg2 Bb6 36. Bxb6
axb6 37. Qg3 Qc1 38. h5 Qc6+ 39. Kf1 Qh1+ 0-1

```

Anand - Touzane
> 12 votes

# Answer
In 2009, GM Nurlan Ibrayev of Kazakhstan (rated 2407 at the time) lost a classical time control game to 9-year-old Hetul Shah of India, who then had a FIDE rating of 1817. Shah's current rating, now three years after that game, is 1979, not so much higher than it was at the time of his upset victory. So this game wasn't a case of Ibrayev running up against some seriously underrated prodigy whose rating was about to shoot up several hundred points. To the contrary, this seems to be exactly the sort of game you are after: a much weaker player having a good day and taking a grandmaster scalp, with the black pieces no less!

```
[FEN ""]
[Event "7th Parsvnath International Open"]
[Site "Delhi"]
[Date "2009.01.11"]
[EventDate "2009.01.11"]
[Round "1.36"]
[Result "0-1"]
[White "Nurlan Ibrayev"]
[Black "Hetul Shah"]
[WhiteElo "2407"]
[BlackElo "1817"]
[PlyCount "88"]

1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O
9.h3 Na5 10.Bc2 c5 11.d4 Qc7 12.Nbd2 cxd4 13.cxd4 Bd7 14.Nf1 Rfc8 15.Ne3 Nc6
16.a3 Bf8 17.b3 Nxd4 18.Nxd4 Qc3 19.Ne2 Qxa1 20.Qd2 d5 21.b4 d4 22.Nd1 Rxc2
23.Qxc2 Rc8 24.Qd2 Nxe4 25.Qd3 Nd6 26.Bb2 Qa2 27.f4 Qc4 28.Qb1 d3 29.Ne3 Qe4
30.Nc3 Qxf4 31.Ncd5 Qg3 32.Nf1 Qg6 33.Bxe5 Nc4 34.Nf4 Qb6+ 35.Kh1 Nxe5 36.Rxe5
Bd6 37.Re4 Bc6 38.Qc1 Qb7 39.Re1 Bxg2+ 40.Nxg2 Rxc1 41.Rxc1 Bf4 42.Rc3 d2
43.Rd3 h6 44.Kg1 Qb6+ 0-1

```
> 15 votes

# Answer
The 2017 Isle of Man Masters tournament provided a couple of these shock results.

First the fairy tale story of an aging, declining US GM overturning an almost 400 point rating difference to beat one of the pre-tournament favourites, ex world champion Vladimir Kramnik.

```
[fen ""]
[Event "Isle of Man Masters"]
[Site "Douglas IMN"]
[Date "2017.09.25"]
[EventDate "2017.09.23"]
[Round "3.28"]
[Result "1-0"]
[White "James Tarjan (2412)"]
[Black "Vladimir Kramnik (2803)"]
[ECO "A12"]
[WhiteElo "2412"]
[BlackElo "2803"]
[PlyCount "111"]

1. c4 Nf6 2. g3 c6 3. Nf3 d5 4. b3 Bg4 5. Bg2 e6 6. O-O Nbd7 7. Bb2 Bd6 8. d3 O-O 9. Nbd2 Re8 10. h3 Bh5 11. Re1 a5 12. a3 e5 13. cxd5 cxd5 14. Nh4 Nc5 15. Qc2 Ne6 16. Rac1 Nd4 17. Qd1 Nb5 18. Nb1 Qd7 19. Kh2 Ra6 20. Nf3 e4 21. dxe4 Nxe4 22. Rf1 Bb8 23. Nc3 Nbxc3 24. Bxc3 Rae6 25. Be1 h6 26. Rc2 Ba7 27. Qc1 Bb6 28. e3 Qb5 29. Nd4 Bxd4 30. exd4 Bf3 31. Bxf3 Nxg3 32. fxg3 Qxf1 33. Bf2 Qd3 34. Rc3 Qf5 35. Kg2 Rf6 36. Qc2 Qd7 37. g4 Rc6 38. Rc5 Rd8 39. Qf5 Rxc5 40. Qxd7 Rxd7 41. dxc5 d4 42. Kf1 d3 43. Ke1 d2+ 44. Kd1 Kf8 45. Bg3 Ke7 46. Bd6+ Ke6 47. Kxd2 b6 48. Ke3 bxc5 49. Bxc5 Rd8 50. b4 axb4 51. axb4 f5 52. b5 fxg4 53. hxg4 g6 54. b6 h5 55. g5 Kd7 56. b7 1-0

```

In the first round an obscure 70 year old English player took a draw by repetition in a winning position against a GM rated almost 700 points higher.

```
[fen ""]
[Event "Isle of Man Masters"]
[Site "Douglas IMN"]
[Date "2017.09.23"]
[EventDate "2017.09.23"]
[Round "1.14"]
[Result "1/2-1/2"]
[White "Zaki Harari (2027)"]
[Black "Maxim Rodshtein (2695)"]
[ECO "B21"]
[WhiteElo "2027"]
[BlackElo "2695"]
[PlyCount "147"]

1. e4 c5 2. d4 cxd4 3. c3 d3 4. Bxd3 Nc6 5. c4 g6 6. Nf3 Bg7 7. O-O d6 8. h3 Nf6 9. Nc3 O-O 10. Be3 Nd7 11. Rc1 Nde5 12. Be2 b6 13. Qd2 Bb7 14. Rfd1 Rc8 15. b3 Nxf3+ 16. Bxf3 Ne5 17. Be2 Nd7 18. Bh6 Nf6 19. Bxg7 Kxg7 20. Bf3 Qc7 21. h4 Qb8 22. h5 Rc5 23. h6+ Kg8 24. Nd5 Bxd5 25. exd5 Rfc8 26. Re1 R8c7 27. a4 Qf8 28. Qf4 a5 29. Qe3 Kh8 30. g4 Ng8 31. g5 f6 32. gxf6 exf6 33. Qf4 Re7 34. Kf1 Re5 35. Rxe5 dxe5 36. Qd2 Qd6 37. Rd1 Rc7 38. Bg2 g5 39. Bh3 Nxh6 40. Be6 Ng8 41. Qe2 Ne7 42. Qf3 Kg7 43. Qh5 Ng6 44. Bf5 Re7 45. Rd3 Nf8 46. Rh3 Kg8 47. Be4 Rg7 48. Bf5 Re7 49. Be4 Qd7 50. Rf3 Rf7 51. Bf5 Qe7 52. Rd3 Qd6 53. Rh3 Rg7 54. Rf3 Qd8 55. Rh3 Ra7 56. Rd3 Qd6 57. Rh3 Rf7 58. Be4 Qa3 59. Bf5 Re7 60. Qd1 Qd6 61. Qd3 Rg7 62. Rh6 g4 63. Qg3 Rg5 64. Be4 Kg7 65. Qh4 Qe7 66. d6 Qf7 67. d7 Qe7 68. Rxh7+ Nxh7 69. Qxh7+ Kf8 70. Qh8+ Rg8 71. Qh6+ Rg7 72. Qh8+ Rg8 73. Qh6+ Rg7 74. Qh8+ 1/2-1/2

```

Bd5 crying out to be played instead of Qh8.
> 5 votes

# Answer
Late to the party, but while Anand losing to a guy, who was rated 400 points below him was, clearly, a huge upset; an IM, who was over 2400 at one point, and 2368 when that game was played is definitely strong enough to take advantage if Anand makes an error.

This still probably beats all upsets I have ever heard of. In the first round, GM John Fedorowicz, rated 2479 at the time (I cannot find this to prove it, but I am recall his USCF rating being in the mid-2500's as well), lost to a 1714 player at the 1980 U.S. Open!

I still remember this because I was a really new player, and saw this game in "Chess Life and Review" (Later shortened to "Chess Life"), and I was amazed. Nevertheless, Fed brushed off the early setback, and tied for first.

http://www.chessgames.com/perl/chessgame?gid=1609849

```
[Title "W Stanley Davis-John Fedorowicz, 81st US Open, 8/3/1980"]
[FEN ""]

1.Nf3 e6 2.e3 b6 3.b3 Bb7 4.Bb2 c5 5.Be2 Nf6 6.d3 d5 7.Nbd2 Be7 8.Ne5 O-O 9.O-O Re8 10.f4 Bf8 11.Qe1 a5 12.g4 a4 13.Rc1 axb3 14.axb3 Ra2 15.Ba1 Na6 16.g5 Nd7 17.Bh5 Nxe5 18.Bxe5 Nb4 19.Qh4 Nxc2 20.Rf3 Nxe3 21.Rxe3 Rxd2 22.Rh3 c4 23.Bf6 Bc5+ 24.Kf1 Bf2 25.Bxf7+ Kf8 26.Qxh7 gxf6 27.Bg6 1-0

```
> 5 votes

# Answer
Here are two examples drawn from Fox and James, *The Complete Chess Addict*, pub. 1987.

```
[Title "Gilberto Garcia - Borislav Ivkov, Capablanca MT 1965"]
[fen ""]

1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.e3 c5
5.dxc5 Bxc5 6.b3 O-O 7.Qc2 Nc6 8.a3 Bb6
9.Bb2 Re8 10.Nc3 d4 11.Rd1 e5 12.e4 Ng4
13.Na4 Ba5+ 14.b4 Nxb4 15.axb4 Bxb4+ 16.Rd2 Bd7
17.Bc1 b5 18.Nb2 Rc8
19.Be2 Be6 20.O-O bxc4 21.Nxc4 Qc7 22.Qa4 Bxd2 23.Bxd2 Bxc4
24.Rc1 Qc6 25.Rxc4 Qxe4 26.Rxc8 Rxc8 27.Qd7 Rf8 28.Bf1 Nf6
29.Qc7 Nd5 30.Qd7 Nf4 31.h3 Qb1
32.Be1? {Best are g3/Bxf4.} e4
33.Qf5 Ne6 34.Bd2 g6
35.Qf6 exf3 36.g4 d3 37.Bc3 {thr Qh8#} 1-0

```

The above game was played in round 20 of 21. After 19 rounds, Ivkov was leading, and was expected to beat the weaker Garcia and clinch first place. He lost his last two games and finished equal 4th.

```
[Title "Jose Raul Capablanca - Alexander Kevitz, simul, 1924"]
[fen ""]

1.b4 d5 2.Bb2 Bf5 3.e3 e6 4.f4 Nf6
5.Nf3 Bxb4 6.Nc3 Nbd7 7.Ne2 Ng4 8.c3 Be7
9.h3 Nc5 {thr Nb3#}
10.Ng3 Bh4 11.Nxh4 Qxh4 12.Qf3 Nxe3
13.Qf2 Nxf1 {White resigned} 0-1

```
> 2 votes

# Answer
In a 1929 against Fritz Saemisch, a lesser master, former World Champion J. R. Capablanca blundered away a piece on the 9th move, and resigned some 50-odd moves later.

http://www.chessgames.com/perl/chessgame?gid=1066901

It was reported that Capablanca'ss wife or mistress (or possibly both) had just entered the room. In any event, the grandmaster LOST the game.
> 1 votes

---
Tags: rating
---


# Question
Title: How big is the advantage for white in the "back-rank-game"?
Consider a chess variant in which normal chess rules apply, with one exception. The player that is able to bring a piece or a pawn onto the opponent’s back rank, which would be the 8th rank for White and the 1st rank for Black, wins immediately. The move has to be legal and it ends the game, even if the opponent could mate on the next move.

On Liches some chess variants like King of the Hill, Atomic, and Three-Check can be analyzed. Can I easily adjust Stockfish or another chess program such that this new rule applies? Would White have a big advantage in this game? Or can we even show that White has a winning strategy?

# Answer
> 3 votes
Revised stockfish and added this goal to win the game.

* Created 22 start opening mostly 2 plies others are 4 plies. Done carefully to minimize white advantage in the opening.

```
[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.e4 c5 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.e4 e5 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.e4 e5 2.Nf3 Nc6 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.e4 e6 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.e4 Nf6 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.e4 Nc6 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.e4 Nc6 2.Nc3 e5 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.e4 d5 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.d4 d5 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.d4 d5 2.Bf4 Bf5 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.d4 Nf6 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.c4 e5 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.c4 c5 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.c4 Nf6 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.c4 d6 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.c4 g6 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.c4 Nc6 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.Nf3 d5 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.Nf3 Nf6 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.Nf3 c5 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.Nf3 e6 *

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]

1.Nf3 d5 2.d4 Bf5 *

```
* Run a match at TC 3m+1s

#### Result

```
Score of sfbackrank_e2 vs sfbackrank_e1: 8 - 13 - 1 [0.386]
...      sfbackrank_e2 playing White: 5 - 5 - 1  [0.500] 11
...      sfbackrank_e2 playing Black: 3 - 8 - 0  [0.273] 11
...      White vs Black: 13 - 8 - 1  [0.614] 22
Elo difference: -80.4 +/- 156.7, LOS: 13.8 %, DrawRatio: 4.5 %
22 of 22 games finished.

```

sfbackrank\_e2 and sfbackrank\_e1 are the same engine. The white side won.

```
White vs Black: 13 - 8 - 1  [0.614] 22

```

#### Sample games

https://lichess.org/Ab5lGE1w
https://lichess.org/4VdHGQkm
https://lichess.org/b8xxzvjZ
https://lichess.org/IVpjazCV
https://lichess.org/gwwYdwCA
https://lichess.org/QdiEcpyK
https://lichess.org/GmCdzkz8
https://lichess.org/cDR66Vuq
https://lichess.org/5Fc6G9MC

# Answer
> -3 votes
Well, since White has the first move, then White would always be trying to put a piece on the back rank, while Black is trying to catch up. So Black can eventually trade off all the pieces, and Black can keep opposition.

However, I'm not sure if this is a legitimate strategy. We would have to solve until we find a forcing winning line or until all possible positions are analyzed before we know the actual result.

---
Tags: software, chess-variants, solving
---


# Question
Title: Meaning of the phrase "the same player has the move"
What is the meaning of the phrase "the same player has the move" in the sentence below

"Two positions are by definition "the same" if the same types of pieces occupy the same squares, the same player has the move, the remaining castling rights are the same and the possibility to capture en passant is the same." The sentence is taken from https://en.wikipedia.org/wiki/Threefold\_repetition.

# Answer
In short, it means that either both positions must be "white to move" (white's turn) or both positions must be "black to move (black's turn). If the pieces are in the same places, but one position is white to move and one position is black to move, they're different positions.
> 12 votes

# Answer
The Wikipedia editors got that from article (.2 the FIDE Laws of Chress.

This is what it says:

> 9.2.1 The game is drawn, upon a correct claim **by a player having the move**, when the same position for at least the third time (not necessarily by a repetition of moves):
> 9.2.1.1 is about to appear, if he first writes his move, which cannot be changed, on his scoresheet and declares to the arbiter his intention to make this move, or
> 9.2.1.2 has just appeared, **and the player claiming the draw has the move**.
> 9.2.2 Positions are considered the same if and only if **the same player has the move**, pieces of the same kind and colour occupy the same squares and the possible moves of all the pieces of both players are the same. Thus positions are not the same if:
>
> 9.2.2.1 at the start of the sequence a pawn could have been captured en passant
> 9.2.2.2 a king had castling rights with a rook that has not been moved, but forfeited these after moving. The castling rights are lost only after the king or rook is moved.

So, what this is saying is that when it is your move, instead of making a move, you can claim a draw provided the position is a third repetition or you could make a move to make it the third repetition of the same position.

What you see in the above description is that to qualify as a repetition of the position every single aspect of the position must be ***exactly*** the same including the person to move.

The significance of "the same player has the move" is that if you are claiming that the position in front of you is a third repetition then on each of the two previous repetition positions it was your move. If you are claiming that by playing a particular move you can repeat the position for the third time then to be true the position which would arise with your opponent to move was identical to the previous two repetition positions and on each it was your opponent's turn to move.
> 4 votes

---
Tags: rules, fide, terminology, threefold-repetition
---


# Question
Title: How can I make my child interested in playing chess?
I am just an OK player and I wish for my eight-year old kid to learn chess and be interested in it too. Can you please give tips/ideas as to how can I make my child interested in it?

# Answer
> 22 votes
In my experience it is likely that kids get interested in whatever you are interested in. So, play a couple of chess games with a friend or set up some chess problems and work on them yourself at a time where your kid can see what you are doing. It is quite likely that your kid will start asking questions what you are doing and wants to play as well.

Whenever my sons sees me setting up the chess board he wants to play... unfortunately he is not even three years old, so besides learning the names of the pieces there is not much he can do yet. ;)

# Answer
> 7 votes
I have grown up loving chess from 4 years old playing a video-game(for Windows DOS), which a lot of old school animations. The game is called "Battle Chess". You can play here: https://classicreload.com/battle-chess.html

# Answer
> 4 votes
Well when I was younger I had this program called Chessmaster 9000. The program itself was extremely oriented in making the concepts obvious. I realize that this isn't really a decent answer, but that is what REALLY got me originally interested. It was much too long for a comment.

# Answer
> 4 votes
I don't like the idea of forcing your child to be interested in it. Neither of my parents knew how to play, and I developed interest when mom bought me Chessmaster on PS2. I played quite regularly for a year until my parents decided to find a junior chess club for me to play in. My dad did teach himself how to play with me, but I had more free time and progressed far more quickly.

I like the idea of letting children explore the game themselves, which helps to develop a lifelong interest. I feel that forcing your child to play chess is like forcing them to learn a musical instrument. If they don't have fun with it, they will most likely quit when they become teenagers and have little to show for it as an adult.

I should mention that I never had a structured study plan when I was younger, just simply playing game after game. Because of the amount of free time I had then, I wish I devoted more of that time to proper chess study, although I never had the resources to know how to do this properly.

I recommend once your child develops an interest themselves, then you can start to guide and help them progress as much as possible. Explaining why they are doing something (and ensuring they understand) is better than forcing it upon them.

If one of the parents plays chess, then the child might naturally become interested in what the parent is doing. However, a key thing for kids is to make it fun. It is crucial to remember that **they are kids**, and you cannot teach them something the same way in which you would teach a beginner adult. In most mammals, the children learn by playing and having fun, while the adults supervise from the side. The same concept applies for most things taught to children.

# Answer
> 3 votes
Chess has become a very young and fashionable sport. To become a good player you need to - First dilute chess complexity for your kid...go step by step.let him get interest. Like 8 Queen puzzle, pawn game only..or let him learn freely.

1. Start early , Take it as Fun , focus on developing interest with easy tools
2. Never force to practice , keep stress totally out .
3. Talk theory don’t teach theory.
4. Ensure getting good result since start..good means genious approach in play, toughness to win.
5. Working more Hrs gives more result
6. Every child is unique , don’t compare speed of learning. Ultimately depth of learning matters
7. Play with stronger opponents

# Answer
> 3 votes
We can learn a few things from the childhoods of Magnus Carlsen, Judit Polgár, and Hikaru Nakamura.

### 1. Don’t pressure your child.

> I felt, OK, they’e definitely not geniuses, but it doesn’t matter. Chess was something we could do together, just a hobby. **— Henrik Carlsen** \[Source\]

> Let the kid own the process and the result. **— Henrik Carlsen** \[Source\]

> I just want him to be happy. And as long as he’s happy, he can do whatever he wants. **— Sigrun Øen** \[Source\]

> I just set things into motion and they did the rest on their own. **— Laszlo Polgár** \[Source\]

> I didn’t want him at first to play chess, because I thought it was unfair to have him measure up to his brother, who was very good… But the more I pushed him away, the more interested he became. **— Sunil Weeramantry** \[Source\]

In interviews, Magnus Carlsen’s father has explained that he initially viewed chess as an enjoyable family pastime and never had any ambitions for his child. Similarly, his mother has said that her focus was on her son’s happiness and not on any kind of success or achievement at the game.

Even though Judit Polgár’s father had aspirations for her and her sisters, he understood that he would succeed only if the children show interest. Laszlo managed to get his daughter interested in chess by creating an environment where chess was present as part of the family home.

As for Hikaru Nakamura, he was already exposed to chess in his childhood since his older brother was a chess player. His stepfather and coach Sunil did not push him into it, and in fact initially tried to do the opposite of that.

### 2. Make it social.

> My sisters also still live at home, so it is quite a family-centred existence. One of the things that first motivated me to take up chess as a child was the desire to beat my elder sister. **— Magnus Carlsen** \[Source\]

> We lived in a small apartment where my sister Susan had already serious chess trainings in the living room behind closed doors. I very much wanted to go in to that room. **— Judit Polgár** \[Source\]

Both Magnus Carlsen and Judit Polgár had the opportunity to play chess with their respective father and older sisters when they were young.

Sometimes a peer with whom a child can play can help cultivate a child’s interest in a certain game or activity. If your child does not have siblings, you can try looking for chess clubs for kids or other opportunities for him/her to play chess with other children.

### 3. Make it fun and don’t overwhelm your child.

> It is a difficult game… I have read some books about supposed prodigies who picked up chess *(snaps fingers)* like that, but I don’t believe those stories anymore. **— Henrik Carlsen** \[Source\]

> I don’t believe that there is one method for everybody. I was being criticized all the way during Hikaru’s upbringing as a chess player that I’m letting him play too much blitz. **— Sunil Weeramantry** \[Source\]

Magnus Carlsen’s father believes that chess is a difficult game, especially when it comes to coordinating one’s pieces together. He has described how he helped Magnus get into it by playing with him using less pieces on the board.

Hikaru’s stepfather has also spoken on the importance of focusing on the aspect of the game that gives the child enjoyment. Hikaru enjoyed playing very fast chess and did not show interest in reading highbrow chess books.

# Answer
> 2 votes
I've seen a few tricks work like:

1. Make silly/simple bets.... like the looser has to do 20 jumping jacks, or something stupid and funny. Makes it more fun and slightly competitive.
2. Have the better player give up a few pieces. Queen, rooks, bishops, knights, whatever. Have the weaker player pick the pieces that have a total maximum value of say 15 points. This teaches the value of the pieces.
3. Have the better player play blindfolded for maybe the first 2,5, or 10 moves, depending on their ability.
4. More time to the weaker player.
5. Start teaching with just a few pieces... Not all of them. Like king/pawn... King rook, king queen. Then they will know what endings to strive to achieve.
6. Some fundamentals like king opposition is important.
7. Capture a piece of candy or pennies on all 64 squares with knight moves. They get to keep what they catch. Or the fewest knight moves.

# Answer
> 2 votes
I have the title of tennis teacher and have been giving lessons to childs for a couple of years and my experienze tells me you cannot.

I remember many childs that came to the tennis lesson while they didn't like or be specially in good in the sport.

Worst is when their parents (who have obligated him do something he or she doesn't like) come to ask you "why does my child doesn't play well forehand?", while first his child has not many tennis habilities, second he or she hasn't show any effort on performing his technic.

This applies to chess, and maybe more. Because you obligate a child to be hours in a closed room thinking on something he really does not want to be thinking on.

---
Tags: psychology, study, teaching, children
---


# Question
Title: Why should Black capture with different pawns in these similar Spanish game variations?
As a general “rule”, I have read that pawn captures toward the center should be preferred. I have found 2 different positions which look similar but the best way for Black to recapture with the pawn is different.

```
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR"]
[Title "Spanish Variation 1"]
[StartFlipped "1"]

1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bc5 5. Bxc6 bxc6!?

```

In the variation above, Black captures toward the center but Stockfish labels it as an inaccuracy and suggests capturing with the d-pawn instead. The advantage goes from `0` to around `+0.6`.

```
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR"]
[Title "Spanish Variation 2"]
[StartFlipped "1"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 Nf6 4. Qe2 Bc5 5. Bxc6 dxc6!?

```

In the second variation, Black does not capture toward the center this time. But Stockfish still labels is as an inaccuracy and suggests capturing with the b-pawn instead. The advantage goes from `0` to around `+0.8`.

---

The positions look very similar to me. Why does Stockfish recommend recapturing in different ways in these positions?

# Answer
> 9 votes
As you attempt to understand chess, one thing that you are probably coming to realize is that almost every rule has exceptions. This is one of the most interesting ones.

The "general rule" to capture towards the center, is strategic, and aims at using the pawns to control the center of the board. The exceptions mostly have to do with tactics. Here we have a situation that is common in the Ruy Lopez. Can White win the e5 Pawn by removing the c6 Knight?

In your first position. 5. .bxc6 can be answered strongly with Nxe5 and recovering the Pawn will be difficult. The Knight can supported with d4, which will come with gain of tempo against Bc5. On the other hand, after ..dxc6 6.Nxe5, Black easily recovers the pawn with 6...Bxf2+ 7.Kxf2 Qd4+. The loss of a central Pawn is fully compensated by a fast and easy development.

In the second position, 5..bxc6 is playable because if 6.Nxe5 Qe7 recovers the Pawn and the supporting move d4 is not available. White has given up the two Bishops to no purpose.

---
Tags: opening, analysis, beginner, ruy-lopez, berlin
---


# Question
Title: Single-line chess notation (Chessable) to tree-like notation (ChessBase)
## Intro to problem

For those who are not familiar with it, Chessable contains high-quality content about "life-time repertories" of most of the main openings and defenses. However, the way they present the lines of moves is extremely inconvenient (see an example in the **image below**); Each line starts from move 1. forcing the user to play the first few moves over and over again.

## Solution

The best way to browse through chess lines is in a tree-like structure, such as the one I manually keyed in below, using ChessBase:

## Goal

The goal is to automatically compute the tree notation from Chessable single lines, so that it can be imported to software like ChessBase.

## Attempt

I browsed to my target repertory in text-mode and copied the single lines into a text file using a text editor.

```
1.d4 Nf6 2.Nc3 d5 3.Bg5 g6 4.Qd2 Bg7 5.O-O-O c6 6.f3 b5 7.e4 b4 8.Nce2 dxe4 9.Bxf6 exf6
1.d4 Nf6 2.Nc3 d5 3.Bg5 g6 4.Qd2 Bg7 5.O-O-O c6 6.f3 b5 7.Bh6 Bxh6 8.Qxh6 Qa5 9.a3 Na6
1.d4 Nf6 2.Nc3 d5 3.Bg5 g6 4.Qd2 Bg7 5.h4 Ne4 6.Nxe4 dxe4 7.e3 c5 8.Ne2 Bg4
1.d4 Nf6 2.Nc3 d5 3.Bg5 g6 4.Qd2 Bg7 5.h4 Ne4 6.Nxe4 dxe4 7.O-O-O Nc6 8.e3 h6 9.Bf4 O-O
1.d4 Nf6 2.Nc3 d5 3.Bg5 g6 4.Qd2 Bg7 5.f3 h6 6.Bxf6 exf6 7.e4 dxe4 8.fxe4 O-O
1.d4 Nf6 2.Nc3 d5 3.Bg5 g6 4.Qd2 Bg7 5.f3 h6 6.Bf4 c5 7.dxc5 Nbd7
1.d4 Nf6 2.Nc3 d5 3.Bg5 g6 4.Qd2 Bg7 5.f3 h6 6.Bh4 c5 7.e3 cxd4 8.exd4 O-O
1.d4 Nf6 2.Nc3 d5 3.Bg5 g6 4.Qd2 Bg7 5.f3 h6 6.Bh4 c5 7.dxc5 O-O 8.Bxf6 Bxf6 9.Qxh6 Qa5 10.Qd2 Rd8
1.d4 Nf6 2.Nc3 d5 3.Bg5 g6 4.Qd2 Bg7 5.f3 h6 6.Bh4 c5 7.dxc5 O-O 8.O-O-O Nc6 9.Nxd5 Nxd5 10.Qxd5 Qa5
1.d4 Nf6 2.Nc3 d5 3.Bg5 g6 4.Qd2 Bg7 5.f3 h6 6.Bh4 c5 7.dxc5 O-O 8.O-O-O Nc6 9.Bxf6 Bxf6 10.Nxd5 Bg7 11.e4 e6 12.Ne3 Qg5 13.Ng4 Qxc5 14.Nxh6+ Kh7 15.Ng4 f5 16.Qg5 Kg8 17.Nh6+ Kh7 18.Ng4 Kg8
1.d4 Nf6 2.Nc3 d5 3.e4 Nxe4 4.Nxe4 dxe4 5.f3 e5 6.dxe5 Qxd1+ 7.Kxd1 Bf5
1.d4 Nf6 2.Nc3 d5 3.e4 Nxe4 4.Nxe4 dxe4 5.Bf4 Bf5 6.Qe2 e6 7.g4 Bg6 8.Qb5+ Nd7 9.Qxb7 Rb8
1.d4 Nf6 2.Nc3 d5 3.e4 Nxe4 4.Nxe4 dxe4 5.Be3 g6 6.f3 Bg7 7.fxe4 c5 8.c3 cxd4 9.cxd4 Qa5+ 10.Qd2 Qxd2+ 11.Kxd2 O-O
1.d4 Nf6 2.Nc3 d5 3.e4 Nxe4 4.Nxe4 dxe4 5.Be3 g6 6.f3 Bg7 7.fxe4 c5 8.c3 cxd4 9.Bxd4 O-O
1.d4 Nf6 2.Nc3 d5 3.e4 Nxe4 4.Nxe4 dxe4 5.Bc4 Nc6 6.c3 e5 7.Qb3 Qf6 8.d5 Bc5 9.f3 Nb8
1.d4 Nf6 2.Nc3 d5 3.e4 Nxe4 4.Nxe4 dxe4 5.Bc4 Nc6 6.c3 e5 7.d5 Ne7 8.Qa4+ Bd7 9.Qb3 Nf5 10.Qxb7 Rb8 11.Qxa7 Ra8 12.Qb7 Nd6 13.Qb3 Rb8
1.d4 Nf6 2.Nc3 d5 3.e4 Nxe4 4.Nxe4 dxe4 5.Bc4 Nc6 6.c3 e5 7.d5 Ne7 8.Qa4+ Bd7 9.Qb3 Nf5 10.Qxb7 Rb8 11.Qa6 e3
1.d4 Nf6 2.Nc3 d5 3.e4 Nxe4 4.Nxe4 dxe4 5.Bc4 Nc6 6.c3 e5 7.d5 Ne7 8.f3 exf3 9.Nxf3 f6
1.d4 Nf6 2.Nc3 d5 3.e3 g6 4.Nf3 Bg7 5.Bd3 O-O 6.O-O c5 7.dxc5 Nbd7 8.Na4 Ne4 9.Bxe4 dxe4 10.Nd4 Qc7 11.b4 Ne5
1.d4 Nf6 2.Nc3 d5 3.e3 g6 4.Nf3 Bg7 5.Bd3 O-O 6.O-O c5 7.dxc5 Nbd7 8.Na4 Ne4 9.Bxe4 dxe4 10.Ng5 Qa5 11.c3 b5 12.Qd5 Qa6 13.Nxf7 e6 14.Qxa8 Bb7
1.d4 Nf6 2.Nc3 d5 3.e3 g6 4.b3 Bg7 5.Bb2 O-O 6.Qd2 c5 7.O-O-O c4 8.bxc4 b5 9.Nxb5 Nc6
1.d4 Nf6 2.Nc3 d5 3.e3 g6 4.b3 Bg7 5.Bb2 O-O 6.Qd2 c5 7.f3 Bh6 8.f4 cxd4 9.exd4 Nc6 10.O-O-O Bf5
1.d4 Nf6 2.Nc3 d5 3.f3 c5 4.e4 Nc6 5.exd5 Nxd5 6.dxc5 Nxc3 7.Qxd8+ Nxd8 8.bxc3 Bd7
1.d4 Nf6 2.Nc3 d5 3.g3 c5 4.Bg2 cxd4 5.Qxd4 Nc6 6.Qd3 d4 7.Ne4 Nd5
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.O-O-O c6 6.f3 b5 7.Kb1 Nbd7
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.h4 c5 7.dxc5 Bxh6 8.Qxh6 d4 9.O-O-O Ng4 10.Qf4 e5 11.Qg3 Qa5
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.h4 c5 7.Bxg7 Kxg7 8.dxc5 d4 9.O-O-O Nc6 10.Nb5 Qd5 11.Kb1 Ne4 12.Qe1 Be6
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.O-O-O c5 7.dxc5 Qa5 8.Bxg7 Kxg7
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.f3 c5 7.Bxg7 Kxg7 8.dxc5 d4 9.Nb5 Nc6 10.Rd1 e5 11.e4 b6
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.f3 c5 7.Bxg7 Kxg7 8.e3 h5
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.Bxg7 Kxg7 7.e3 c5 8.dxc5 Qa5 9.Ne4 Qxd2+ 10.Nxd2 Bf5 11.Bd3 Nbd7 12.Nb3 Rfc8
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.Bxg7 Kxg7 7.Nf3 Qd6
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.Bxg7 Kxg7 7.O-O-O c5 8.dxc5 Qa5 9.Kb1 Nc6 10.Nxd5 Qxd2 11.Rxd2 Ne4
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.Bxg7 Kxg7 7.O-O-O c5 8.dxc5 Qa5 9.Nxd5 Qxa2 10.Nc3 Qa1+ 11.Nb1 Be6 12.b3 Rc8
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.Bxg7 Kxg7 7.O-O-O c5 8.dxc5 Qa5 9.Nxd5 Qxa2 10.Qc3 Be6 11.e4 Bxd5 12.exd5 Kg8 13.Qa3 Qxa3 14.bxa3 Rc8
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.Bxg7 Kxg7 7.O-O-O c5 8.dxc5 Qa5 9.Nxd5 Qxa2 10.Qc3 Be6 11.e4 Bxd5 12.exd5 Kg8 13.b3 Qa3+ 14.Kb1 a5
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.Bxg7 Kxg7 7.O-O-O c5 8.dxc5 Qa5 9.Nxd5 Qxa2 10.Qc3 Be6 11.Nxf6 exf6 12.Nf3 Nd7
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Qd2 Bg7 5.Bh6 O-O 6.Bxg7 Kxg7 7.O-O-O c5 8.e3 c4 9.e4 b5 10.e5 Ng8 11.Nxb5 Nc6 12.Kb1 f6 13.Na3 Qb6 14.exf6+ Nxf6 15.f3 Rb8 16.c3 e5
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.Nb5 Na6 5.e3 Bg7 6.Nc3 Nh5 7.Be5 f6 8.Bg3 Nxg3 9.hxg3 O-O 10.Bxa6 bxa6
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.f3 Bg7 5.e4 O-O 6.e5 Nfd7 7.Nxd5 c5 8.c3 cxd4 9.cxd4 Qa5+ 10.Nc3 Rd8
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.f3 Bg7 5.e4 O-O 6.e5 Nfd7 7.Be3 c5 8.f4 e6
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.f3 Bg7 5.Qd2 c5 6.e4 cxd4 7.Nb5 O-O 8.Nc7 e5
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.f3 Bg7 5.Qd2 c5 6.dxc5 Nc6 7.e4 d4 8.Nb5 O-O
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Qf3 c5 7.Qg3 Nc6 8.Bc7 Qd7 9.O-O-O cxd4 10.exd4 O-O
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Be2 c5 8.Nb5 cxd4 9.Nc7 Ng4 10.Nxa8 e5
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Be2 c5 8.Nb5 cxd4 9.exd4 Nc6 10.Nc7 Rb8 11.Nb5 Bf5 12.Bxb8 Qxb8
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Be2 c5 8.dxc5 Qa5 9.O-O Qxc5 10.Nb5 a6 11.Nc7 Ra7 12.a3 Bf5 13.Nd4 Bg4 14.f3 Bd7 15.Nb3 Qc6 16.Nd4 Qb6
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Be2 c5 8.dxc5 Qa5 9.O-O Qxc5 10.Nb5 a6 11.Nc7 Ra7 12.Nb5 axb5 13.Bxb8 Ra4
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Be2 c5 8.Qd2 cxd4 9.exd4 Nc6 10.Ne5 Bf5 11.f3 Rc8 12.Nxc6 Rxc6 13.Be5 Qa5
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Be2 c5 8.Qd2 cxd4 9.exd4 Nc6 10.Ne5 Bf5 11.f3 Rc8 12.g4 hxg4 13.h5 Nxh5 14.fxg4 Nxf4 15.Qxf4 Bxc2 16.Qh2 Re8 17.Qh7+ Kf8 18.Nxf7 Kxf7 19.Rf1+ Ke6 20.Qxg7 Qa5
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Be2 c5 8.Ne5 cxd4 9.exd4 Nc6 10.O-O Bf5 11.Nxc6 bxc6
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Qd2 c5 8.dxc5 Nbd7 9.Bd3 Nxc5 10.O-O-O Bg4
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Nb5 Na6 8.Be2 c6 9.Nc3 Bf5
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Nb5 Na6 8.Ne5 c5 9.c3 Nb8
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Ne5 c5 8.dxc5 Qa5 9.Qd2 Be6
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Ne5 c5 8.dxc5 Qa5 9.Qd4 Ng4 10.Qxd5 Nc6
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Ne5 c5 8.Qd2 cxd4 9.exd4 Nc6 10.f3 Bf5 11.Nxc6 bxc6 12.O-O-O c5 13.Be5 Rc8 14.Ba6 cxd4 15.Qxd4 Rc6 16.Bb7 Re6 17.Bxd5 Rxe5 18.Qxe5 Nxd5 19.Qxd5 Qc7
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Ne5 c5 8.Qd2 cxd4 9.exd4 Nc6 10.f3 Bf5 11.Bb5 Nxe5 12.dxe5 Nd7 13.Qxd5 Qb6 14.Bxd7 Qxb2 15.O-O Qxc3
1.d4 Nf6 2.Nc3 d5 3.Bf4 g6 4.e3 Bg7 5.h4 h5 6.Nf3 O-O 7.Ne5 c5 8.Qd2 cxd4 9.exd4 Nc6 10.f3 Bf5 11.O-O-O Rc8 12.g4 hxg4 13.h5 Nxe5 14.Bxe5 Nxh5 15.fxg4 Bxg4 16.Be2 Bxe2 17.Qxe2 f6

```

I tried to create a python program (**failed attempt at the bottom**) that converts the text file to tree notation (**see example**), but my programming skills are too poor. Essentially, if we export the tree notation (ChessBase) to a text editor, the syntax looks like this:

```
1. d4 Nf6 2. Nc3 d5 3. Bg5 g6 4. Qd3 Bg7 5. e4 (5. O-O-O c6 (5... Nbd7)) 5...
dxe4 6. Nxe4 Bf5 7. Bxf6 exf6

```

The new line, or variant, is introduced by a pair of parenthesis and the move number (e.g. 5..., for black, and 5. for white). I would appreciate help to convert single-line notation to tree notation. It could be useful to many chess fans.

```
with open('./text.txt') as f:
    list_of_lines = f.readlines()

list_of_lines = [line[:-1] for line in list_of_lines] # to remove /n
tree = ''
for idx, line in enumerate(list_of_lines[:2]):
    if idx == 0:
        tree += line
    else:
        prev_line = list_of_lines[idx-1]
        prev_moves = prev_line.split(' ')
        new_moves = line.split(' ')

        for prev in prev_moves:
            for i, new in enumerate(new_moves):
                if prev == new:
                    continue
                else:
                    if (i % 2) != 0:
                        variant = f' ({i}...'
                        variant += str(f'{new_moves[i:]})')
                        (' ').join(variant)
                        tree += variant

print(tree)

```

## \[Solved\] Update on Kentdjb's answer

1. Create .py file (e.g., tree.py) with the code from the accepted answer.
2. Create a .txt (e.g. veresov.txt) file with the single-line notation such as in "Attempt" example above.
3. To run the code, use `python tree.py veresov.txt`

It outputs the desired tree notation:

```
1. d4 Nf6 2. Nc3 d5 3. Bg5 (3. e4 Nxe4 4. Nxe4 dxe4 5. f3 (5. Bf4 Bf5 6. Qe2 e6 7. g4 Bg6 8. Qb5+ Nd7 9. Qxb7 Rb8 ) (5. Be3 g6 6. f3 Bg7 7. fxe4 c5 8. c3 cxd4 9. cxd4 (9. Bxd4 O-O ) 9... Qa5+ 10. Qd2 Qxd2+ 11. Kxd2 O-O ) (5. Bc4 Nc6 6. c3 e5 7. Qb3 (7. d5 Ne7 8. Qa4+ (8. f3 exf3 9. Nxf3 f6 ) 8... Bd7 9. Qb3 Nf5 10. Qxb7 Rb8 11. Qxa7 (11. Qa6 e3 ) 11... Ra8 12. Qb7 Nd6 13. Qb3 Rb8 ) 7... Qf6 8. d5 Bc5 9. f3 Nb8 ) 5... e5 6. dxe5 Qxd1+ 7. Kxd1 Bf5 ) (3. e3 g6 4. Nf3 (4. b3 Bg7 5. Bb2 O-O 6. Qd2 c5 7. O-O-O (7. f3 Bh6 8. f4 cxd4 9. exd4 Nc6 10. O-O-O Bf5 ) 7... c4 8. bxc4 b5 9. Nxb5 Nc6 ) 4... Bg7 5. Bd3 O-O 6. O-O c5 7. dxc5 Nbd7 8. Na4 Ne4 9. Bxe4 dxe4 10. Nd4 (10. Ng5 Qa5 11. c3 b5 12. Qd5 Qa6 13. Nxf7 e6 14. Qxa8 Bb7 ) 10... Qc7 11. b4 Ne5 ) (3. f3 c5 4. e4 Nc6 5. exd5 Nxd5 6. dxc5 Nxc3 7. Qxd8+ Nxd8 8. bxc3 Bd7 ) (3. g3 c5 4. Bg2 cxd4 5. Qxd4 Nc6 6. Qd3 d4 7. Ne4 Nd5 ) (3. Bf4 g6 4. Qd2 (4. Nb5 Na6 5. e3 Bg7 6. Nc3 Nh5 7. Be5 f6 8. Bg3 Nxg3 9. hxg3 O-O 10. Bxa6 bxa6 ) (4. f3 Bg7 5. e4 (5. Qd2 c5 6. e4 (6. dxc5 Nc6 7. e4 d4 8. Nb5 O-O ) 6... cxd4 7. Nb5 O-O 8. Nc7 e5 ) 5... O-O 6. e5 Nfd7 7. Nxd5 (7. Be3 c5 8. f4 e6 ) 7... c5 8. c3 cxd4 9. cxd4 Qa5+ 10. Nc3 Rd8 ) (4. e3 Bg7 5. h4 h5 6. Qf3 (6. Nf3 O-O 7. Be2 (7. Qd2 c5 8. dxc5 Nbd7 9. Bd3 Nxc5 10. O-O-O Bg4 ) (7. Nb5 Na6 8. Be2 (8. Ne5 c5 9. c3 Nb8 ) 8... c6 9. Nc3 Bf5 ) (7. Ne5 c5 8. dxc5 (8. Qd2 cxd4 9. exd4 Nc6 10. f3 Bf5 11. Nxc6 (11. Bb5 Nxe5 12. dxe5 Nd7 13. Qxd5 Qb6 14. Bxd7 Qxb2 15. O-O Qxc3 ) (11. O-O-O Rc8 12. g4 hxg4 13. h5 Nxe5 14. Bxe5 Nxh5 15. fxg4 Bxg4 16. Be2 Bxe2 17. Qxe2 f6 ) 11... bxc6 12. O-O-O c5 13. Be5 Rc8 14. Ba6 cxd4 15. Qxd4 Rc6 16. Bb7 Re6 17. Bxd5 Rxe5 18. Qxe5 Nxd5 19. Qxd5 Qc7 ) 8... Qa5 9. Qd2 (9. Qd4 Ng4 10. Qxd5 Nc6 ) 9... Be6 ) 7... c5 8. Nb5 (8. dxc5 Qa5 9. O-O Qxc5 10. Nb5 a6 11. Nc7 Ra7 12. a3 (12. Nb5 axb5 13. Bxb8 Ra4 ) 12... Bf5 13. Nd4 Bg4 14. f3 Bd7 15. Nb3 Qc6 16. Nd4 Qb6 ) (8. Qd2 cxd4 9. exd4 Nc6 10. Ne5 Bf5 11. f3 Rc8 12. Nxc6 (12. g4 hxg4 13. h5 Nxh5 14. fxg4 Nxf4 15. Qxf4 Bxc2 16. Qh2 Re8 17. Qh7+ Kf8 18. Nxf7 Kxf7 19. Rf1+ Ke6 20. Qxg7 Qa5 ) 12... Rxc6 13. Be5 Qa5 ) (8. Ne5 cxd4 9. exd4 Nc6 10. O-O Bf5 11. Nxc6 bxc6 ) 8... cxd4 9. Nc7 (9. exd4 Nc6 10. Nc7 Rb8 11. Nb5 Bf5 12. Bxb8 Qxb8 ) 9... Ng4 10. Nxa8 e5 ) 6... c5 7. Qg3 Nc6 8. Bc7 Qd7 9. O-O-O cxd4 10. exd4 O-O ) 4... Bg7 5. O-O-O (5. Bh6 O-O 6. h4 (6. O-O-O c5 7. dxc5 Qa5 8. Bxg7 Kxg7 ) (6. f3 c5 7. Bxg7 Kxg7 8. dxc5 (8. e3 h5 ) 8... d4 9. Nb5 Nc6 10. Rd1 e5 11. e4 b6 ) (6. Bxg7 Kxg7 7. e3 (7. Nf3 Qd6 ) (7. O-O-O c5 8. dxc5 (8. e3 c4 9. e4 b5 10. e5 Ng8 11. Nxb5 Nc6 12. Kb1 f6 13. Na3 Qb6 14. exf6+ Nxf6 15. f3 Rb8 16. c3 e5 ) 8... Qa5 9. Kb1 (9. Nxd5 Qxa2 10. Nc3 (10. Qc3 Be6 11. e4 (11. Nxf6 exf6 12. Nf3 Nd7 ) 11... Bxd5 12. exd5 Kg8 13. Qa3 (13. b3 Qa3+ 14. Kb1 a5 ) 13... Qxa3 14. bxa3 Rc8 ) 10... Qa1+ 11. Nb1 Be6 12. b3 Rc8 ) 9... Nc6 10. Nxd5 Qxd2 11. Rxd2 Ne4 ) 7... c5 8. dxc5 Qa5 9. Ne4 Qxd2+ 10. Nxd2 Bf5 11. Bd3 Nbd7 12. Nb3 Rfc8 ) 6... c5 7. dxc5 (7. Bxg7 Kxg7 8. dxc5 d4 9. O-O-O Nc6 10. Nb5 Qd5 11. Kb1 Ne4 12. Qe1 Be6 ) 7... Bxh6 8. Qxh6 d4 9. O-O-O Ng4 10. Qf4 e5 11. Qg3 Qa5 ) 5... c6 6. f3 b5 7. Kb1 Nbd7 ) 3... g6 4. Qd3 (4. Qd2 Bg7 5. O-O-O (5. h4 Ne4 6. Nxe4 dxe4 7. e3 (7. O-O-O Nc6 8. e3 h6 9. Bf4 O-O ) 7... c5 8. Ne2 Bg4 ) (5. f3 h6 6. Bxf6 (6. Bf4 c5 7. dxc5 Nbd7 ) (6. Bh4 c5 7. e3 (7. dxc5 O-O 8. Bxf6 (8. O-O-O Nc6 9. Nxd5 (9. Bxf6 Bxf6 10. Nxd5 Bg7 11. e4 e6 12. Ne3 Qg5 13. Ng4 Qxc5 14. Nxh6+ Kh7 15. Ng4 f5 16. Qg5 Kg8 17. Nh6+ Kh7 18. Ng4 Kg8 ) 9... Nxd5 10. Qxd5 Qa5 ) 8... Bxf6 9. Qxh6 Qa5 10. Qd2 Rd8 ) 7... cxd4 8. exd4 O-O ) 6... exf6 7. e4 dxe4 8. fxe4 O-O ) 5... c6 6. f3 b5 7. e4 (7. Bh6 Bxh6 8. Qxh6 Qa5 9. a3 Na6 ) 7... b4 8. Nce2 dxe4 9. Bxf6 exf6 ) 4... Bg7 5. e4 dxe4 6. Nxe4 Bf5 7. Bxf6 exf6

```

# Answer
Here's some Python code to attempt to get what you want, but you would likely have a richer set of tools to work with if you can represents your data in PGN format. The script reads the input file passed as the single command-line argument.

```
import re
import sys
# Create and print a tree of variations from individual lines of moves.
# The moves don't have a result terminator and neither does the output.

def createTree(lines : list) -> dict:
    """ Create a tree from the variations """
    tree = dict()
    for line in lines:
        moves = [m for m in re.sub('[1-9][0-9]*\\.', '', line).split(' ') if m != '']
        node = tree
        index = 0
        while index < len(moves) and moves[index] in node:
            node = node[moves[index]]
            index += 1
        while index < len(moves):
            node[moves[index]] = dict()
            node = node[moves[index]]
            index += 1
    return tree

def printline(node : dict, moveNumber : int, whiteToMove : bool):
    """ Print the lines whose first moves are the keys
        of the given node.
        Treat one as the main line and the rest as
        sub-variations. The order is arbitrary.
    """
    variations = list(node.keys())
    if variations != []:
        if whiteToMove:
            print(str(moveNumber) + '.', end = ' ')
        print(variations[0], end = ' ')
        for idx in range(1, len(variations)):
            print('(', end = '')
            print(moveNumber, end ='')
            if whiteToMove:
                print('.', end = ' ')
            else:
                print('...', end = ' ')
            print(variations[idx], end = ' ')
            printline(node[variations[idx]], moveNumber if whiteToMove else moveNumber + 1, not whiteToMove)
            print(')', end = ' ')
        if whiteToMove and len(variations) > 1:
            print(str(moveNumber) + '...', end = ' ')
        printline(node[variations[0]], moveNumber if whiteToMove else moveNumber + 1, not whiteToMove)

def printTree(tree : dict):
    """ Each key in tree is the first move of a game.
        Print each first move as a separate line.
    """
    for firstmove in tree:
        print('1.', firstmove, end = ' ')
        printline(tree[firstmove], 1, False)

if len(sys.argv) == 2:
    f = open(sys.argv[1])
    lines = f.read().strip().split('\n')
    tree = createTree(lines)
    printTree(tree)
else:
    print('Usage:', sys.argv[0],'file-of-lines')

```
> 3 votes

# Answer
You could use https://github.com/permutationlock/merge-pgn to merge multiple games into a single game with variations.

Also you may want to look at the code. It is small and does not rely on string manipulation.
> 3 votes

---
Tags: programming, notation, chessbase
---


# Question
Title: How quickly after a tournament are USCF ratings updated?
I see that for international ratings they are updated once per month using all results from completed tournaments in that month. When are USCF updated and published?

# Answer
> 1 votes
Official USCF ratings are updated once per month. From the USCF's web site, this text appears in every player's rating record online:

> *The ratings shown on this page are official published ratings, which US Chess issues 12 times a year. As of September 1, 2013, Official ratings lists are generated on the 3rd Wednesday of each month and become official on the 1st day of the next month.*

Unofficial rating updates are calculated quickly after an organizer submits a rating report for a tournament, and are usually available to view within a few hours of when the rating report is submitted. But these unofficial rating updates are exactly that - they're unofficial, they're not used for pairings or determining things like what section you can be in in a tournament, and they're subject to change and re-rating - most commonly, because the rating reports for events that a player participated in were submitted out of order. So, if a player plays in an event, the rating report is submitted, and within a few hours an unofficial estimated post-event rating is published. If then, a few days later, a rating report is submitted for another tournament that the player had participated in, that actually ended prior to when the first rating report was submitted, the player's post-event rating estimate for the other event (the one that the first rating report was submitted for) will be recalculated. But, as stated, these are just estimates, and they're not official in any way - they don't become official until the first day of the following month - and any changes that take place due to events that happen between the time the official ratings are calculated on the 3rd Wednesday of the month, and the first day of the following month, don't become official until the first day of the month after that.

---
Tags: rating, uscf
---


title: FIDE Rating Distribution

text:
# Question
Title: FIDE Rating Distribution
This answer has a link to the Lichess blitz rating distribution which looks like this:

It looks like a good approximation to a normal distribution, perhaps slightly skewed to the upper half, and has an interesting sawtooth appearance with spikes on the 100 marks. This is for blitz.

I'm really curious as to what is going on here and for comparison would like the FIDE standard rating distribution to see if it is similar as that might give some more insights into what is going on.

# Answer
It is first worth visiting the Lichess link and having a closer look at their sawtooth curve. They do not plot individual rating points. Instead they round to the nearest 25 point. So, it is not the case that you have local maxima exactly on each 100 point. We don't know how they round their numbers so we don't really know what is going on.

Here is the rating distribution for FIDE standard rating data extracted from the January 2022 data:

Three things stand out.

1. It's not really a normal distribution
2. There looks to be a discontinuity about the 2000 mark, almost as if two different distributions have been stitched together
3. There are two massive spikes at 2005 and 2205. The 2004 count is 316 and 2005 is 440. The 2204 count is 141, 2205 count is 291.

For comparison here is the same data graphed for FIDE Bltiz:

So, also not really a normal distribution but no discontinuities and no significant spikes.

The numbers 2005 and 2205 *are* significant numbers in FIDE rating history. Take a look at this rating distribution for January 1992 extracted from FIDE standard rating data obtained from the Olimpbase:

Here there are quite clearly two graphs added together and there are massive spikes at 2005 and 2205.

The explanation for this is that in the early days you didn't get a FIDE rating unless you were over 2000 for females and over 2200 for males and because in those days FIDE ratings were in increments of 5 that meant you had to get at least 2005 if you were female and 2205 if you were male.
> 8 votes

# Answer
Some distribution based on 2022-01 FIDE blitz xml file.

#### 1. All players

#### 2. Rating and title

#### 3. Age and title

#### 4. Juniors with title

#### 5. U-25 with 2600 and above blitz rating

```
                  name country sex title  rating  birthday  age
     Firouzja, Alireza     FRA   M    GM    2791    2003.0 19.0
        Erigaisi Arjun     IND   M    GM    2745    2003.0 19.0
           Nihal Sarin     IND   M    GM    2705    2004.0 18.0
Abdusattorov, Nodirbek     UZB   M    GM    2663    2004.0 18.0
     Muradli, Mahammad     AZE   M    IM    2645    2003.0 19.0
    Niemann, Hans Moke     USA   M    GM    2636    2003.0 19.0
    Sindarov, Javokhir     UZB   M    GM    2630    2005.0 17.0
      Sadhwani, Raunak     IND   M    GM    2616    2005.0 17.0

```

#### 6. Top countries with promising young players

U-25 with 2200 and above blitz rating. count is the number of players, mean is the mean rating of those players.

**Table 1**

```
u25 blitz rating >= 2200, sorted by count:
         rating
           mean count
country
RUS      2313.0   143
GER      2311.0    67
IND      2369.0    46
UKR      2324.0    33
USA      2389.0    31
CHN      2333.0    26
ESP      2291.0    24
HUN      2316.0    22
IRI      2333.0    20
FRA      2309.0    19
POL      2359.0    18
CZE      2295.0    17
CUB      2276.0    17
SRB      2346.0    17
AZE      2329.0    15
KAZ      2357.0    15
ITA      2304.0    14
NOR      2387.0    13
ISR      2327.0    13
ARM      2403.0    12
AUT      2332.0    12
GRE      2322.0    12
SVK      2330.0    11
NED      2482.0     8
ENG      2275.0     8
SLO      2315.0     8
CRO      2338.0     8
TUR      2397.0     8
MDA      2318.0     7
SWE      2276.0     7
CAN      2292.0     7
UZB      2490.0     7
GEO      2269.0     6
ROU      2362.0     6
BLR      2306.0     6

```

**Table 2**

```
u25 blitz rating >= 2200, sorted by mean rating:
         rating
           mean count
country
UZB      2490.0     7
NED      2482.0     8
ARM      2403.0    12
TUR      2397.0     8
USA      2389.0    31
NOR      2387.0    13
IND      2369.0    46
ROU      2362.0     6
POL      2359.0    18
KAZ      2357.0    15
SRB      2346.0    17
CRO      2338.0     8
CHN      2333.0    26
IRI      2333.0    20
AUT      2332.0    12
SVK      2330.0    11
AZE      2329.0    15
ISR      2327.0    13
UKR      2324.0    33
GRE      2322.0    12
MDA      2318.0     7
HUN      2316.0    22
SLO      2315.0     8
RUS      2313.0   143
GER      2311.0    67
FRA      2309.0    19
BLR      2306.0     6
ITA      2304.0    14
CZE      2295.0    17
CAN      2292.0     7
ESP      2291.0    24
CUB      2276.0    17
SWE      2276.0     7
ENG      2275.0     8
GEO      2269.0     6

```
> 1 votes

---
Tags: fide, rating, statistics
---


# Question
Title: Need Techniques for Bishop and Knight Checkmate
I understand the process for how to checkmate once in this position:

```
[fen "7k/8/5K2/5B2/5N2/8/8/8 w - - 0 1"]

```

But I need a technique for reliably getting into that kind of position from, say, here (or any other arbitrary position), while under time pressure (I understand it isn't analogous because different color bishop, but, you know, the idea):

```
[fen "8/8/8/8/4k3/8/8/2B1KN2 w - - 0 1"]

```

A lot of the things I look up (e.g. Wikipedia) will list moves, but those seem specific to the initial position and aren't a strategy to apply generally.

# Answer
The technique is basically to use all three pieces to push the black king to the edge of the board. The king and knight move "slowly" and you should not leave either one behind. Black's objective is to try and keep the king as close to the center as possible and then to prefer the corner of the opposite colour to the bishop rather than the closer to the center of the edge because that is closer to the wrong colour corner.

Your first objective is to get *your* king to the center (one of e4, e5, d4, d5) when, by definition, your opponent's king has to vacate the center.

From your position it could go something like this:

```
[fen "8/8/8/8/4k3/8/8/2B1KN2 w - - 0 1"]

1. Ke2 Kd4 2. Ng3 {don't leave the knight behind and don't block your own king or bishop} Kc4 3. Ke3 {The black king is nearer the a file than the 8th rank. Encourage it in that direction} Kd5 {Staying as close to the center as possible} 4. Bb2 {a better diagonal for the bishop, controlling center square e5} Kd6 {Success! The black king can't stop the white king going to a center square on the next move} 5. Ke4 {First goal accomplished} Kc6 6. Nf5 {Don't leave the knight behind} Kc5 7. Be5 Kc6 (7...Kc4? {allows white's next pushing the black king closer to the edge} 8. Bd4! Kb5 9. Kd5) 8. Kd4 Kb6 9. Kd5 Kb7 10. Kc5 Ka7 11. Kc6 Ka8 12. Nd6 {don't leave the knight behind and get ready for the "W" to drive the black king out of the "wrong" corner}

```
> 4 votes

# Answer
The triangle method

(https://www.youtube.com/watch?v=r3EqM17jvOc&ab\_channel=ChessNetwork)

provides a simpler method over the w method. Of course, the best answer is to practice until you can do this in your sleep.
> 1 votes

---
Tags: endgame, checkmate
---


title: Attacking the Spanish Opening

text:
# Question
Title: Attacking the Spanish Opening
I'm studying the Spanish opening by developing some possible attacks against it and seeing how it could resist those attacks.

In the below position, White has moved the light-squared bishop from f1 to b5, after which Black attacked it.

```
[FEN "rnbqkb1r/3p1ppp/2p2n2/1p2p3/p3P3/1B1P1N2/PPP2PPP/RNBQ1RK1 w Qkq - 0 1"]

```

I'm struggling with what should be considered an **optimal** move for the shackled bishop.

# Answer
White's best move is to use the Desperado tactic at this point reaching a position where Black is up material but can't castle and is slightly behind in development. There is nothing better for White.

Stockfish 14+ NNUE evaluation is -2.6 (depth = 34, 7450k nodes/s) with best play starting with **1. Bxf7+** to at least snag a pawn for the Bishop and damage the structure around Black's King (source).

The diagram gives the top two lines from the Engine Overlord's perspective.

```
[FEN "rnbqkb1r/3p1ppp/2p2n2/1p2p3/p3P3/1B1P1N2/PPP2PPP/RNBQ1RK1 w Qkq - 0 1"]

1. Bxf7+ Kxf7 2. Nxe5+ Kg8 3. b3 d6 4. Nf3 h6 5. bxa4 bxa4 6. Re1 Nbd7 7. Nbd2 Ne5 8. d4 Nxf3+
(1. Bxa4 {Stockfish rates this line as -4.6.} bxa4 2. Nxe5 d5 3. c4 dxe4 4. dxe4 Qxd1 5. Rxd1 Be6)

```

Other moves (e.g., 1. Bxa4, 1. Nxe5, 1. d4, 1. Nc3) are decidedly worse for White.
> 2 votes

# Answer
1 - This is not the Spanish Opening as Black did not play 2...Nc6

It appears to be a rather poor trap in the Open Game by Black against a White player that might be inclined to play the Spanish:

1. e4 e5
2. Nf3 a5? { leaving the e5 pawn undefended }
3. Bb5? { avoiding to capture the undefended e5 pawn } ...Nf6!?
4. d3?? c6
5. Ba4 b5
6. Bb3 a4

or perhaps from the Petrov's Defense by reversing Nf6 and a5

2 - Either way White should not have played Bb5. Bb5 is not a normal choice in the Petrov's Defense for White. Nxe5 would be better. And Bb5 is simply a tactical mistake after the opponent plays 2...a5.

So the conclusion is to not try and find a way out of this horrible position but to avoid getting in this position. If you decide to play a certain opening, be it the Spanish Opening or whatever, and you don't make your decisions based on your opponent's replies then you will fall for traps. If you are going to play the Spanish Opening, then you should know how to play against the Petrov's Defense and you should be aware of the a5, c6, b5, a6 trap against Bb5. It is a common theme in many openings involving Bb5 and Bf5.
> 2 votes

---
Tags: opening, bishops, ruy-lopez, attack
---


# Question
Title: What's the strongest non-ML chess engine?
What's the current strongest Chess Engine built solely on heuristics, no neural networks or any kind of deep learning?

# Answer
The strongest classical chess engine is probably Stockfish classical, i.e. Stockfish with its NNUE turned off. I say this because Stockfish was leagues ahead of all its CPU rivals before the NNUE revolution, and after the NNUE revolution very few people are still working on classical engines, so it's unlikely anyone caught Stockfish. In fact, if you look at CCRL (Computer Chess Rating Lists), no classical engine has caught Houdini (all the engines above it are either NN or NNUE based).
> 4 votes

---
Tags: engines
---