opelly/Stockfish
1
0
Fork 0
mirror of https://github.com/opelly27/Stockfish.git synced 2026-05-20 13:17:44 +00:00
Code Issues Packages Projects Releases Wiki Activity

Introduce concept of double pawn protection.

Browse Source 
Exclude doubly protected by pawns squares when calculating attackers on
king ring. Idea of this patch is not to count attackers if they attack
only squares that are protected by two pawns.

STC
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 70040 W: 15476 L: 15002 D: 39562
http://tests.stockfishchess.org/tests/view/5c0354860ebc5902bcee1106

LTC
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 16530 W: 2795 L: 2607 D: 11128
http://tests.stockfishchess.org/tests/view/5c0385080ebc5902bcee14b5

This is third king safety patch in recent times so we probably need
retuning of king safety parameters.

Bench: 3057978
This commit is contained in:
Vizvezdenec
2018-12-02 20:18:14 +01:00
committed by Stéphane Nicolet
parent 982fd9c8bc
commit 9dc6d270fc
2 changed files with 11 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/evaluate.cpp
+1 -1
View File
@@ -309,7 +309,7 @@ namespace {
attackedBy[Us][Pt] |= b;
attackedBy[Us][ALL_PIECES] |= b;
if (b & kingRing[Them])
if (b & kingRing[Them] & ~double_pawn_attacks_bb<Them>(pos.pieces(Them, PAWN)))
{
kingAttackersCount[Us]++;
kingAttackersWeight[Us] += KingAttackWeights[Pt];