kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-05-01 09:13:08 +00:00
Code Issues Releases Wiki Activity

Change advanced pawn push threshold

Browse source 
A pawn push is now considered to be "advanced" if the relative destination
rank is > 6 (previously it was > 5). This affects the search heuristic.

Also remove an assert concerning en passant moves in qsearch().

STC:
LLR: 2.97 (-2.94,2.94) {-0.25,1.25}
Total: 46744 W: 4224 L: 4040 D: 38480
Ptnml(0-2): 165, 3206, 16451, 3380, 170
https://tests.stockfishchess.org/tests/view/604746082433018de7a3872e

LTC:
LLR: 2.94 (-2.94,2.94) {0.25,1.25}
Total: 107840 W: 4198 L: 3892 D: 99750
Ptnml(0-2): 58, 3472, 46557, 3772, 61
https://tests.stockfishchess.org/tests/view/60475eae2433018de7a38737

Closes https://github.com/official-stockfish/Stockfish/pull/3389

Bench: 4796780
This commit is contained in:
Topologist 2021-03-08 19:46:41 +01:00 • committed by Stéphane Nicolet
parent b74274628c
commit f3b296c2e2
3 changed files with 3 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
AUTHORS
View file

@ -168,6 +168,7 @@ Sergio Vieri (sergiovieri)
sf-x sf-x
Shane Booth (shane31) Shane Booth (shane31)
Shawn Varghese (xXH4CKST3RXx) Shawn Varghese (xXH4CKST3RXx)
Siad Daboul (Topologist)
Stefan Geschwentner (locutus2) Stefan Geschwentner (locutus2)
Stefano Cardanobile (Stefano80) Stefano Cardanobile (Stefano80)
Steinar Gunderson (sesse) Steinar Gunderson (sesse)

2
src/position.h
View file

@ -312,7 +312,7 @@ inline bool Position::pawn_passed(Color c, Square s) const {
inline bool Position::advanced_pawn_push(Move m) const { inline bool Position::advanced_pawn_push(Move m) const {
return type_of(moved_piece(m)) == PAWN return type_of(moved_piece(m)) == PAWN
&& relative_rank(sideToMove, to_sq(m)) > RANK_5; && relative_rank(sideToMove, to_sq(m)) > RANK_6;
} }
inline int Position::pawns_on_same_color_squares(Color c, Square s) const { inline int Position::pawns_on_same_color_squares(Color c, Square s) const {

4
src/search.cpp
View file

@ -1575,15 +1575,13 @@ moves_loop: // When in check, search starts from here
moveCount++; moveCount++;
// Futility pruning // Futility pruning and moveCount pruning
if ( bestValue > VALUE_TB_LOSS_IN_MAX_PLY if ( bestValue > VALUE_TB_LOSS_IN_MAX_PLY
&& !givesCheck && !givesCheck
&& futilityBase > -VALUE_KNOWN_WIN && futilityBase > -VALUE_KNOWN_WIN
&& !pos.advanced_pawn_push(move)) && !pos.advanced_pawn_push(move))
{ {
assert(type_of(move) != EN_PASSANT); // Due to !pos.advanced_pawn_push
// moveCount pruning
if (moveCount > 2) if (moveCount > 2)
continue; continue;