From d1ec10cd4fe1e67114178f444cfebd2ff1183408 Mon Sep 17 00:00:00 2001 From: Stefan Geschwentner Date: Sun, 31 May 2020 17:00:47 +0200 Subject: [PATCH] Give bonus for bishops that are alligned with enemy kingring. Inspired by the succesful patch "Give bonus for rooks that are alligned with enemy kingring" from Vizvezdenec, this idea has been reused for bishops. Here, we only consider attacks that are not blocked by any pawn. Also we have a 50% higher bonus than for the rooks. STC: LLR: 2.94 (-2.94,2.94) {-0.50,1.50} Total: 68960 W: 13495 L: 13202 D: 42263 Ptnml(0-2): 1213, 8018, 15802, 8157, 1290 https://tests.stockfishchess.org/tests/view/5ed27495042fa6d77c3553aa LTC: LLR: 2.96 (-2.94,2.94) {0.25,1.75} Total: 54560 W: 7105 L: 6780 D: 40675 Ptnml(0-2): 379, 4986, 16254, 5253, 408 https://tests.stockfishchess.org/tests/view/5ed30375596e6dc1e1f97425 closes https://github.com/official-stockfish/Stockfish/pull/2708 Bench: 4860021 --- src/evaluate.cpp | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/evaluate.cpp b/src/evaluate.cpp index ad79db5c..dc7134a8 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -128,6 +128,7 @@ namespace { // Assorted bonuses and penalties constexpr Score BishopPawns = S( 3, 7); + constexpr Score BishopOnKingRing = S( 24, 0); constexpr Score BishopXRayPawns = S( 4, 5); constexpr Score CorneredBishop = S( 50, 50); constexpr Score FlankAttacks = S( 8, 0); @@ -288,9 +289,13 @@ namespace { kingAttackersWeight[Us] += KingAttackWeights[Pt]; kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]); } + else if (Pt == ROOK && (file_bb(s) & kingRing[Them])) score += RookOnKingRing; + else if (Pt == BISHOP && (attacks_bb(s, pos.pieces(PAWN)) & kingRing[Them])) + score += BishopOnKingRing; + int mob = popcount(b & mobilityArea[Us]); mobility[Us] += MobilityBonus[Pt - 2][mob]; -- 2.39.5