More accurate pawn attack span definition
authorMoez Jellouli <37274752+MJZ1977@users.noreply.github.com>
Fri, 27 Sep 2019 08:18:22 +0000 (10:18 +0200)
committerStéphane Nicolet <cassio@free.fr>
Wed, 2 Oct 2019 11:37:00 +0000 (13:37 +0200)
commite6f4b5f46344d638c5e3b27cdbc966899e80e8d6
treedea9984f71806720798537caa70ea1b61ee3ba8c
parent005ad170c1dccdcd4ce73074302828ea22628b70
More accurate pawn attack span definition

Tweak the pawn attack span for backward pawns and the zone behind
opponent opposing pawns. This is important in positional play and
one of weaknesses of the engine in recent high level games.

STC
LLR: -2.95 (-2.94,2.94) [0.50,4.50]
Total: 66843 W: 14884 L: 14717 D: 37242
http://tests.stockfishchess.org/tests/view/5d8dcb1b0ebc590f3beb2956

LTC
LLR: 2.96 (-2.94,2.94) [0.00,3.50]
Total: 77699 W: 12993 L: 12602 D: 52104
http://tests.stockfishchess.org/tests/view/5d8de9bc0ebc590f3beb3d00

See discussion in https://github.com/official-stockfish/Stockfish/pull/2332

Bench: 4012371
src/evaluate.cpp
src/pawns.cpp