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Re: Shogi Perft numbers
Posted: Sat Aug 24, 2019 11:25 am
by hgm
Patrice Duhamel wrote: ↑Sat Aug 24, 2019 11:23 am
What GUI are using USI protocol ?
Shogidogoro, BCM Games and gShogi. And perhaps Tagua.
Re: Shogi Perft numbers
Posted: Sat Aug 24, 2019 12:33 pm
by Ferdy
Patrice Duhamel wrote: ↑Sat Aug 24, 2019 11:23 am
What GUI are using USI protocol ?
There is also ShogiGui, and of course Winboard.
Re: Shogi Perft numbers
Posted: Wed Sep 04, 2019 1:08 am
by IanO
I've never concerned myself with perft in my game programs before, but is it supposed to detect checkmates in order to avoid playing past fools mates? I was wondering if
could be used to enumerate all the shortest mates in shogi.
Re: Shogi Perft numbers
Posted: Wed Sep 04, 2019 8:55 am
by hgm
Sure. Perft only considers legal moves, so it cannot calculate past stalemate or checkmate. It does calculate past 3-fold reps, though.
Re: Shogi Perft numbers
Posted: Wed Sep 04, 2019 6:34 pm
by Patrice Duhamel
IanO wrote: ↑Wed Sep 04, 2019 1:08 am
I've never concerned myself with perft in my game programs before, but is it supposed to detect checkmates in order to avoid playing past fools mates? I was wondering if
could be used to enumerate all the shortest mates in shogi.
There are 29 mate positions at depth 7 :
Code: Select all
nodes = 15 086 269 607
Captures = 156 289 904
Promotions = 78 496 954
Drops = 22 189 844
Checks = 79 636 812
Mates = 29
Re: Shogi Perft numbers
Posted: Mon Sep 09, 2019 11:32 pm
by IanO
Patrice Duhamel wrote: ↑Wed Sep 04, 2019 6:34 pm
IanO wrote: ↑Wed Sep 04, 2019 1:08 am
I've never concerned myself with perft in my game programs before, but is it supposed to detect checkmates in order to avoid playing past fools mates? I was wondering if
could be used to enumerate all the shortest mates in shogi.
There are 29 mate positions at depth 7 :
Code: Select all
nodes = 15 086 269 607
Captures = 156 289 904
Promotions = 78 496 954
Drops = 22 189 844
Checks = 79 636 812
Mates = 29
Thanks! Those stats were perfect for verifying the shogi perft I wrote this weekend. Turns out there are 11 unique 7-move mate positions in shogi, expressing 6 themes:
[d]lnfw1wfnl/5rkb1/pppppppWp/9/9/9/PPPPPPP1P/1B5R1/LNFWKWFNL b
[d]lnfw1kQnl/1r2wB3/pppppp1pp/6p2/9/2P6/PP1PPPPPP/7R1/LNFWKWFNL b
[d]lnfw1w1nl/1r2kB1b1/ppppFp1pp/4p4/9/2P6/PP1PPPPPP/7R1/LNFWKWFNL b
[d]lnfww1Qnl/1r2k2b1/ppppFpppp/4p4/9/P8/1PPPPPPPP/7R1/LNFWKWFNL b
[d]lnfwB2nl/1r2kWfb1/pppppp1pp/9/9/2P6/PP1PPPPPP/7R1/LNFWKWFNL b
[d]lnf3fnl/1rwkWQ1b1/pppppp1pp/9/9/2P6/PP1PPPPPP/7R1/LNFWKWFNL b
The 29 transpositions and 5 other mate positions are left as an exercise for the reader.
(The fairy FEN support here doesn't support the "+P" style of indicating promoted pieces as in SFEN. I've used 'W' for promoted pawn (same as for gold general) and 'Q' for promoted bishop.)
Re: Shogi Perft numbers
Posted: Tue Sep 10, 2019 12:57 pm
by hgm
[d]lnf3fnl/1rwkWI1b1/pppppp1pp/9/9/2P6/PP1PPPPPP/7R1/LNFWKWFNL b
Yeah, sorry about that. The diagram script still needs some work for the support of fairy pieces, which I so far postponed. For one, I would like to support all XBoard pieces, of which there are now 66, and obvioulsy 1-letter encoding will fail. The symbols XBoard's default theme uses for Shogi Horse and Dragon are currently available as I and J, but I don't think the Gold-like symbols for promoted P, N, L, S can currently be selected.
Of course +P, +N, +L and +S would be obvious choices for their two-character IDs, and +B, +R would be preferable over I, J. To further expand the set I was thinking of punctuation suffixes on the letters, like L', L`, L" or L!
Re: Shogi Perft numbers
Posted: Tue Sep 10, 2019 6:42 pm
by Patrice Duhamel
hgm wrote: ↑Tue Sep 10, 2019 12:57 pm
[d]lnf3fnl/1rwkWI1b1/pppppp1pp/9/9/2P6/PP1PPPPPP/7R1/LNFWKWFNL b
Why "Black" and "White" are inverted in Winboard ?
In others GUI Black is the first player.
Code: Select all
Winboard :
lns3snl/1rgkG+B1b1/pppppp1pp/9/9/2P6/PP1PPPPPP/7R1/LNSGKGSNL[P] b 0 4
ShogiGUI or BCMGames :
lns3snl/1rgkG+B1b1/pppppp1pp/9/9/2P6/PP1PPPPPP/7R1/LNSGKGSNL w P 8
Re: Shogi Perft numbers
Posted: Tue Sep 10, 2019 7:46 pm
by hgm
In other Chess variants white is first player.
WinBoard uses ordinary FEN as part of CECP. ShogiGUI and BCMgames uses the incompatible SFEN as part of USI.