]> git.sesse.net Git - stockfish/commit
Verified SEE pruning for capturing and checking moves.
authorpb00067 <pb00067@phxl0401.wp.lan>
Mon, 20 Mar 2023 07:56:44 +0000 (08:56 +0100)
committerJoost VandeVondele <Joost.VandeVondele@gmail.com>
Sat, 25 Mar 2023 08:17:44 +0000 (09:17 +0100)
commit24b37e4586ba610d331048446bd036bec5544c4f
tree4abca10a44cbf8926bf3dac4971969435930dbbf
parent02e4697055519ed206fa76e4ef9abb9f156cd1a0
Verified SEE pruning for capturing and checking moves.

Patch analyzes field after SEE exchanges concluded with a recapture by
the opponent:
if opponent Queen/Rook/King results under attack after the exchanges, we
consider the move sharp and don't prune it.

Important note:
By accident I forgot to adjust 'occupied' when the king takes part in
the exchanges.
As result of this a move is considered sharp too, when opponent king
apparently can evade check by recapturing.
Surprisingly this seems contribute to patch's strength.

STC:
https://tests.stockfishchess.org/tests/view/640b16132644b62c33947397
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 116400 W: 31239 L: 30817 D: 54344
Ptnml(0-2): 350, 12742, 31618, 13116, 374

LTC:
https://tests.stockfishchess.org/tests/view/640c88092644b62c3394c1c5
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 177600 W: 47988 L: 47421 D: 82191
Ptnml(0-2): 62, 16905, 54317, 17436, 80

closes https://github.com/official-stockfish/Stockfish/pull/4453

bench: 5012145
src/movepick.cpp
src/movepick.h
src/position.cpp
src/position.h
src/search.cpp