X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=0642c6799041632263aad067557b2f010df019e6;hp=40037bba47ed82e93e106a7828688ced284b4556;hb=56dd58e6f9d9073b963ebf2add7da9723eb5cd5a;hpb=55758344d3ccf49353bcd8f3a06a4553ff1b753a diff --git a/src/pawns.cpp b/src/pawns.cpp index 40037bba..0642c679 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -2,6 +2,7 @@ Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -31,65 +32,58 @@ namespace { #define V Value #define S(mg, eg) make_score(mg, eg) - // Doubled pawn penalty by file - const Score Doubled[FILE_NB] = { - S(13, 43), S(20, 48), S(23, 48), S(23, 48), - S(23, 48), S(23, 48), S(20, 48), S(13, 43) }; - // Isolated pawn penalty by opposed flag and file const Score Isolated[2][FILE_NB] = { - { S(37, 45), S(54, 52), S(60, 52), S(60, 52), - S(60, 52), S(60, 52), S(54, 52), S(37, 45) }, - { S(25, 30), S(36, 35), S(40, 35), S(40, 35), - S(40, 35), S(40, 35), S(36, 35), S(25, 30) } }; + { S(31, 36), S(45, 41), S(50, 41), S(50, 41), + S(50, 41), S(50, 41), S(45, 41), S(31, 36) }, + { S(21, 24), S(30, 28), S(33, 28), S(33, 28), + S(33, 28), S(33, 28), S(30, 28), S(21, 24) } }; // Backward pawn penalty by opposed flag - const Score Backward[2] = { S(67, 42), S(49, 24) }; + const Score Backward[2] = { S(56, 33), S(41, 19) }; + + // Unsupported pawn penalty for pawns which are neither isolated or backward, + // by number of pawns it supports [less than 2 / exactly 2]. + const Score Unsupported[2] = { S(17, 8), S(21, 12) }; // Connected pawn bonus by opposed, phalanx, twice supported and rank Score Connected[2][2][2][RANK_NB]; - // Levers bonus by rank - const Score Lever[RANK_NB] = { - S( 0, 0), S( 0, 0), S(0, 0), S(0, 0), - S(20,20), S(40,40), S(0, 0), S(0, 0) }; - - // Unsupported pawn penalty - const Score UnsupportedPawnPenalty = S(20, 10); - - // Center bind bonus: Two pawns controlling the same central square - const Bitboard CenterBindMask[COLOR_NB] = { - (FileDBB | FileEBB) & (Rank5BB | Rank6BB | Rank7BB), - (FileDBB | FileEBB) & (Rank4BB | Rank3BB | Rank2BB) - }; + // Doubled pawn penalty by file + const Score Doubled[FILE_NB] = { + S(11, 34), S(17, 38), S(19, 38), S(19, 38), + S(19, 38), S(19, 38), S(17, 38), S(11, 34) }; - const Score CenterBind = S(16, 0); + // Lever bonus by rank + const Score Lever[RANK_NB] = { + S( 0, 0), S( 0, 0), S(0, 0), S(0, 0), + S(17, 16), S(33, 32), S(0, 0), S(0, 0) }; // Weakness of our pawn shelter in front of the king by [distance from edge][rank] const Value ShelterWeakness[][RANK_NB] = { - { V( 97), V(21), V(26), V(51), V(87), V( 89), V( 99) }, - { V(120), V( 0), V(28), V(76), V(88), V(103), V(104) }, - { V(101), V( 7), V(54), V(78), V(77), V( 92), V(101) }, - { V( 80), V(11), V(44), V(68), V(87), V( 90), V(119) } }; + { V( 97), V(21), V(26), V(51), V(87), V( 89), V( 99) }, + { V(120), V( 0), V(28), V(76), V(88), V(103), V(104) }, + { V(101), V( 7), V(54), V(78), V(77), V( 92), V(101) }, + { V( 80), V(11), V(44), V(68), V(87), V( 90), V(119) } }; // Danger of enemy pawns moving toward our king by [type][distance from edge][rank] const Value StormDanger[][4][RANK_NB] = { - { { V( 0), V( 67), V( 134), V(38), V(32) }, - { V( 0), V( 57), V( 139), V(37), V(22) }, - { V( 0), V( 43), V( 115), V(43), V(27) }, - { V( 0), V( 68), V( 124), V(57), V(32) } }, - { { V(20), V( 43), V( 100), V(56), V(20) }, - { V(23), V( 20), V( 98), V(40), V(15) }, - { V(23), V( 39), V( 103), V(36), V(18) }, - { V(28), V( 19), V( 108), V(42), V(26) } }, - { { V( 0), V( 0), V( 75), V(14), V( 2) }, - { V( 0), V( 0), V( 150), V(30), V( 4) }, - { V( 0), V( 0), V( 160), V(22), V( 5) }, - { V( 0), V( 0), V( 166), V(24), V(13) } }, - { { V( 0), V(-283), V(-281), V(57), V(31) }, - { V( 0), V( 58), V( 141), V(39), V(18) }, - { V( 0), V( 65), V( 142), V(48), V(32) }, - { V( 0), V( 60), V( 126), V(51), V(19) } } }; + { { V( 0), V( 67), V( 134), V(38), V(32) }, + { V( 0), V( 57), V( 139), V(37), V(22) }, + { V( 0), V( 43), V( 115), V(43), V(27) }, + { V( 0), V( 68), V( 124), V(57), V(32) } }, + { { V(20), V( 43), V( 100), V(56), V(20) }, + { V(23), V( 20), V( 98), V(40), V(15) }, + { V(23), V( 39), V( 103), V(36), V(18) }, + { V(28), V( 19), V( 108), V(42), V(26) } }, + { { V( 0), V( 0), V( 75), V(14), V( 2) }, + { V( 0), V( 0), V( 150), V(30), V( 4) }, + { V( 0), V( 0), V( 160), V(22), V( 5) }, + { V( 0), V( 0), V( 166), V(24), V(13) } }, + { { V( 0), V(-283), V(-281), V(57), V(31) }, + { V( 0), V( 58), V( 141), V(39), V(18) }, + { V( 0), V( 65), V( 142), V(48), V(32) }, + { V( 0), V( 60), V( 126), V(51), V(19) } } }; // Max bonus for king safety. Corresponds to start position with all the pawns // in front of the king and no enemy pawn on the horizon. @@ -116,7 +110,7 @@ namespace { Bitboard ourPawns = pos.pieces(Us , PAWN); Bitboard theirPawns = pos.pieces(Them, PAWN); - e->passedPawns[Us] = 0; + e->passedPawns[Us] = e->pawnAttacksSpan[Us] = 0; e->kingSquares[Us] = SQ_NONE; e->semiopenFiles[Us] = 0xFF; e->pawnAttacks[Us] = shift_bb(ourPawns) | shift_bb(ourPawns); @@ -130,8 +124,8 @@ namespace { File f = file_of(s); - // This file cannot be semi-open e->semiopenFiles[Us] &= ~(1 << f); + e->pawnAttacksSpan[Us] |= pawn_attack_span(Us, s); // Flag the pawn neighbours = ourPawns & adjacent_files_bb(f); @@ -169,7 +163,7 @@ namespace { assert(opposed | passed | (pawn_attack_span(Us, s) & theirPawns)); // Passed pawns will be properly scored in evaluation because we need - // full attack info to evaluate passed pawns. Only the frontmost passed + // full attack info to evaluate them. Only the frontmost passed // pawn on each file is considered a true passed pawn. if (passed && !doubled) e->passedPawns[Us] |= s; @@ -182,7 +176,7 @@ namespace { score -= Backward[opposed]; else if (!supported) - score -= UnsupportedPawnPenalty; + score -= Unsupported[more_than_one(neighbours & rank_bb(s + Up))]; if (connected) score += Connected[opposed][!!phalanx][more_than_one(supported)][relative_rank(Us, s)]; @@ -197,10 +191,6 @@ namespace { b = e->semiopenFiles[Us] ^ 0xFF; e->pawnSpan[Us] = b ? int(msb(b) - lsb(b)) : 0; - // Center binds: Two pawns controlling the same central square - b = shift_bb(ourPawns) & shift_bb(ourPawns) & CenterBindMask[Us]; - score += popcount(b) * CenterBind; - return score; } @@ -214,7 +204,7 @@ namespace Pawns { void init() { - static const int Seed[RANK_NB] = { 0, 6, 15, 10, 57, 75, 135, 258 }; + static const int Seed[RANK_NB] = { 0, 8, 19, 13, 71, 94, 169, 324 }; for (int opposed = 0; opposed <= 1; ++opposed) for (int phalanx = 0; phalanx <= 1; ++phalanx) @@ -223,7 +213,7 @@ void init() { int v = (Seed[r] + (phalanx ? (Seed[r + 1] - Seed[r]) / 2 : 0)) >> opposed; v += (apex ? v / 2 : 0); - Connected[opposed][phalanx][apex][r] = make_score(3 * v / 2, v); + Connected[opposed][phalanx][apex][r] = make_score(v, v * 5 / 8); } }