ShashChess

[Ozymandias]

I suspect that most of the Elo gains for SF won't come from improving neither the classical eval, nor the new one, but rather from tuning when to use one or the other. We know search was already excellent, so I don't expect that to contribute much growth either.

[amchess]

Added linux versions:
https://github.com/amchess/ShashChess/releases/tag/14

[MikeB]

Added linux versions:
https://github.com/amchess/ShashChess/releases/tag/14

Good work - your work inspire me to get Shashin's book. I noticed that your T, P and C options are set to false, I'm assuming that is for best play. Was wondering how much Elo loss ( or perhaps gain) have you measured with T, P & C set to true?

[carldaman]

http://talkchess.com/forum3/viewtopic.p ... in#p533571

I just realized that seven years ago I was the first to post about Shashin's book and its potential for aiding engines and not just humans.

[amchess]

Every position can be of type
Tal, Capablanca, Petrosian or mixed type: Tal-Capablanca or Capablanca-Petrosian:
As rule of thumb, if you set the contempt to 0 and reset any dynamic contempt,
if on a position the engine like stockfish shows a score

• <-0.25 the position is of Petrosian type

• =-0.25 the position is of Petrosian-Capablanca type (the so called caos positions in terms of Shashin theory)

• between -0.25 and 0.25 the position is of Capablanca type

• =0.25 the position is of Capablanca-Tal type (the other type of so called caos positions in terms of Shashin theory)

• >0.25 the position is of Tal type

There is also, strictly speaking a final caos positions type: Tal, Capablanca and Petrosian.
This is for positions where even the above rule of thumb can't be applied.
Those positions can be reocognized because the engine's score swing very frequently between the indicated ranges.
Anyway, if, for a position, you know a priori the Shashin's type, if you check the corresponding checkbox(es), the analysis will be better, but surely the default option is the best for match playing, because the initial position is even (capablanca type also equivalent to unchecked boxes).

[Paloma]

http://talkchess.com/forum3/viewtopic.p ... in#p533571

I just realized that seven years ago I was the first to post about Shashin's book and its potential for aiding engines and not just humans.

The Link to Chessvibes don't exist anymore.
I got it via Wayback.

http://web.archive.org/web/201309090544 ... -best-play

btw. is chessvibes.com home page dead?

[BrendanJNorman]

btw. is chessvibes.com home page dead?

Chessvibes was acquired by chess.com a few years ago, I believe.

One of the big chess sites anyway...pretty sure it was chess.com.

[Ozymandias]

Every position can be of type
Tal, Capablanca, Petrosian or mixed type: Tal-Capablanca or Capablanca-Petrosian:
As rule of thumb, if you set the contempt to 0 and reset any dynamic contempt,
if on a position the engine like stockfish shows a score

• <-0.25 the position is of Petrosian type

• =-0.25 the position is of Petrosian-Capablanca type (the so called caos positions in terms of Shashin theory)

• between -0.25 and 0.25 the position is of Capablanca type

• =0.25 the position is of Capablanca-Tal type (the other type of so called caos positions in terms of Shashin theory)

• >0.25 the position is of Tal type

There is also, strictly speaking a final caos positions type: Tal, Capablanca and Petrosian.
This is for positions where even the above rule of thumb can't be applied.
Those positions can be reocognized because the engine's score swing very frequently between the indicated ranges.
Anyway, if, for a position, you know a priori the Shashin's type, if you check the corresponding checkbox(es), the analysis will be better, but surely the default option is the best for match playing, because the initial position is even (capablanca type also equivalent to unchecked boxes).

I'm not familiar with the book, but from what I recall about the theory, it was about evaluating positions. If the evaluation is in the nnue file, how does Shashchess apply Shashin's theory? Trough search alone? Does it apply Tal, Capablanca, Petrosian values afterwards to guide it?

[amchess]

Hi.
Many thanks for the interesting question.
Clearly, Shashin's theory must be adapted to a chess engine.
If you sees the code, the position's nature is etablished at each depth from the previous depth static/quiescent position.
The initial position is "bootstrapped" by the three Shashin's options.

[amchess]

https://github.com/amchess/ShashChess/releases/tag/15