Hello,
I have noticed that forcing engines to play against each other with a given depth, during engames, they reach very fast the depth (so play very fast) even if there are a lot of moves to consider (for humans), is there a reason why?
Engine depth during endgame
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- Full name: Richard Porti
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Re: Engine depth during endgame
When the board is sparse there are not nearly so many moves to compute.
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Re: Engine depth during endgame.
Hello Richard:
I agree with Dann. Just to bring some numbers into the scene, perft can be useful as well as the number of unique positions. Please imagine the starting position with well-known numbers:
Then imagine the same with the longest loss of the side with more pawns in KQPPvKQP endgame:
https://syzygy-tables.info/?fen=8/8/P7/ ... _w_-_-_0_1
The values of the KQPPvKQP endgame were calculated with JetChess perft counter. It depends on the endgame, but branching factors are key in the explanation. Those numbers are not meant to be understood as an axiom since usual engines do not perform brute force analysis (i.e. searching all the nodes). Engines prune but they prune in both positions and the search tree is usually narrower with less pieces on the board, hence searching deeper in the same amount of time.
Regards from Spain.
Ajedrecista.
I agree with Dann. Just to bring some numbers into the scene, perft can be useful as well as the number of unique positions. Please imagine the starting position with well-known numbers:
Code: Select all
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
Plies Perft(Plies) Positions(Plies)
0 1 1
1 20 20
2 400 400
3 8,902 5,362
4 197,281 72,078
5 4,865,609 822,518
6 119,060,324 9,417,683
7 3,195,901,860 96,400,335
8 84,998,978,956 988,192,872
https://syzygy-tables.info/?fen=8/8/P7/ ... _w_-_-_0_1
Code: Select all
8/8/P7/1q6/4P3/6Q1/p7/k4K2 w - - 0 1
Plies Perft(Plies) Positions(Plies)
0 1 1
1 5 5
2 122 122
3 2,777 2,478
4 53,927 13,905
5 1,163,367 79,735
6 23,058,437 376,367
7 489,451,797 1,353,023
8 9,984,707,331 7,135,215
Regards from Spain.
Ajedrecista.
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- Full name: Richard Porti
Re: Engine depth during endgame
Very useful information, thank you to both of you