X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=c29fd5e651a46bd5a46af414b256f2923f6a029d;hp=3e396af3032d6e11c2329d15763853f0f4f85b8f;hb=ef8acdc73b7818e97617ba666398be1f9045998e;hpb=9d5d69e435443cf768be7fdde76070e776db120f diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 3e396af3..c29fd5e6 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -52,19 +52,23 @@ namespace { int WeightPassedPawnsMidgame = 0x100; int WeightPassedPawnsEndgame = 0x100; int WeightKingSafety[2] = { 0x100, 0x100 }; + int WeightSpace; // Internal evaluation weights. These are applied on top of the evaluation // weights read from UCI parameters. The purpose is to be able to change // the evaluation weights while keeping the default values of the UCI // parameters at 100, which looks prettier. - const int WeightMobilityMidgameInternal = 0x100; - const int WeightMobilityEndgameInternal = 0x100; - const int WeightPawnStructureMidgameInternal = 0x100; - const int WeightPawnStructureEndgameInternal = 0x100; - const int WeightPassedPawnsMidgameInternal = 0x100; - const int WeightPassedPawnsEndgameInternal = 0x100; - const int WeightKingSafetyInternal = 0x100; - const int WeightKingOppSafetyInternal = 0x100; + // + // Values modified by Joona Kiiski + const int WeightMobilityMidgameInternal = 0x0FA; + const int WeightMobilityEndgameInternal = 0x10A; + const int WeightPawnStructureMidgameInternal = 0x0EC; + const int WeightPawnStructureEndgameInternal = 0x0CD; + const int WeightPassedPawnsMidgameInternal = 0x108; + const int WeightPassedPawnsEndgameInternal = 0x109; + const int WeightKingSafetyInternal = 0x0F7; + const int WeightKingOppSafetyInternal = 0x101; + const int WeightSpaceInternal = 0x02F; // Visually better to define tables constants typedef Value V; @@ -165,18 +169,19 @@ namespace { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8 }; - // Bonus for unstoppable passed pawns: + // Bonus for unstoppable passed pawns const Value UnstoppablePawnValue = Value(0x500); - // Rooks and queens on the 7th rank: - const Value MidgameRookOn7thBonus = Value(50); - const Value EndgameRookOn7thBonus = Value(100); - const Value MidgameQueenOn7thBonus = Value(25); - const Value EndgameQueenOn7thBonus = Value(50); + // Rooks and queens on the 7th rank + const Value MidgameRookOn7thBonus = Value(47); + const Value EndgameRookOn7thBonus = Value(98); + const Value MidgameQueenOn7thBonus = Value(27); + const Value EndgameQueenOn7thBonus = Value(54); - // Rooks on open files: - const Value RookOpenFileBonus = Value(40); - const Value RookHalfOpenFileBonus = Value(20); + + // Rooks on open files + const Value RookOpenFileBonus = Value(43); + const Value RookHalfOpenFileBonus = Value(19); // Penalty for rooks trapped inside a friendly king which has lost the // right to castle: @@ -203,6 +208,19 @@ namespace { ((1ULL << SQ_A8) | (1ULL << SQ_H8)) }; + // The SpaceMask[color] contains area of the board which is consdered by + // the space evaluation. In the middle game, each side is given a bonus + // based on how many squares inside this area are safe and available for + // friendly minor pieces. + const Bitboard SpaceMask[2] = { + (1ULL< + void evaluate_pieces(const Position& p, Color us, EvalInfo& ei); + + template<> + void evaluate_pieces(const Position& p, Color us, EvalInfo &ei); void evaluate_passed_pawns(const Position &pos, EvalInfo &ei); void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us, @@ -270,6 +287,7 @@ namespace { void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us, EvalInfo &ei); + void evaluate_space(const Position &p, Color us, EvalInfo &ei); inline Value apply_weight(Value v, int w); Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]); @@ -337,52 +355,22 @@ Value evaluate(const Position &pos, EvalInfo &ei, int threadID) { // Evaluate pieces for (Color c = WHITE; c <= BLACK; c++) { - // Knights - for (int i = 0; i < pos.piece_count(c, KNIGHT); i++) - evaluate_knight(pos, pos.piece_list(c, KNIGHT, i), c, ei); - - // Bishops - for (int i = 0; i < pos.piece_count(c, BISHOP); i++) - evaluate_bishop(pos, pos.piece_list(c, BISHOP, i), c, ei); - - // Rooks - for (int i = 0; i < pos.piece_count(c, ROOK); i++) - evaluate_rook(pos, pos.piece_list(c, ROOK, i), c, ei); - - // Queens - for(int i = 0; i < pos.piece_count(c, QUEEN); i++) - evaluate_queen(pos, pos.piece_list(c, QUEEN, i), c, ei); - - // Special pattern: trapped bishops on a7/h7/a2/h2 - Bitboard b = pos.bishops(c) & MaskA7H7[c]; - while (b) - { - Square s = pop_1st_bit(&b); - evaluate_trapped_bishop_a7h7(pos, s, c, ei); - } - - // Special pattern: trapped bishops on a1/h1/a8/h8 in Chess960: - if (Chess960) - { - b = pos.bishops(c) & MaskA1H1[c]; - while (b) - { - Square s = pop_1st_bit(&b); - evaluate_trapped_bishop_a1h1(pos, s, c, ei); - } - } - - // Sum up all attacked squares - ei.attackedBy[c][0] = ei.attackedBy[c][PAWN] | ei.attackedBy[c][KNIGHT] - | ei.attackedBy[c][BISHOP] | ei.attackedBy[c][ROOK] - | ei.attackedBy[c][QUEEN] | ei.attackedBy[c][KING]; + evaluate_pieces(pos, c, ei); + evaluate_pieces(pos, c, ei); + evaluate_pieces(pos, c, ei); + evaluate_pieces(pos, c, ei); + + // Sum up all attacked squares + ei.attackedBy[c][0] = ei.attackedBy[c][PAWN] | ei.attackedBy[c][KNIGHT] + | ei.attackedBy[c][BISHOP] | ei.attackedBy[c][ROOK] + | ei.attackedBy[c][QUEEN] | ei.attackedBy[c][KING]; } // Kings. Kings are evaluated after all other pieces for both sides, // because we need complete attack information for all pieces when computing // the king safety evaluation. for (Color c = WHITE; c <= BLACK; c++) - evaluate_king(pos, pos.king_square(c), c, ei); + evaluate_pieces(pos, c, ei); // Evaluate passed pawns. We evaluate passed pawns for both sides at once, // because we need to know which side promotes first in positions where @@ -407,6 +395,13 @@ Value evaluate(const Position &pos, EvalInfo &ei, int threadID) { ei.mgValue += ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK); + + // Evaluate space for both sides + if (ei.mi->space_weight() > 0) + { + evaluate_space(pos, WHITE, ei); + evaluate_space(pos, BLACK, ei); + } } // Mobility @@ -414,7 +409,7 @@ Value evaluate(const Position &pos, EvalInfo &ei, int threadID) { ei.egValue += apply_weight(ei.egMobility, WeightMobilityEndgame); // If we don't already have an unusual scale factor, check for opposite - // colored bishop endgames, and use a lower scale for those: + // colored bishop endgames, and use a lower scale for those if ( phase < PHASE_MIDGAME && pos.opposite_colored_bishops() && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && ei.egValue > Value(0)) @@ -461,7 +456,7 @@ Value quick_evaluate(const Position &pos) { assert(pos.is_ok()); static const - ScaleFactor sf[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL}; + ScaleFactor sf[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL}; Value mgv = pos.mg_value(); Value egv = pos.eg_value(); @@ -495,7 +490,10 @@ void init_eval(int threads) { } for (Bitboard b = 0ULL; b < 256ULL; b++) - BitCount8Bit[b] = count_1s(b); + { + assert(count_1s(b) == int(uint8_t(count_1s(b)))); + BitCount8Bit[b] = (uint8_t)count_1s(b); + } } @@ -527,6 +525,7 @@ void read_weights(Color us) { WeightKingSafety[us] = weight_option("Cowardice", WeightKingSafetyInternal); WeightKingSafety[them] = weight_option("Aggressiveness", WeightKingOppSafetyInternal); + WeightSpace = weight_option("Space", WeightSpaceInternal); init_safety(); } @@ -536,34 +535,47 @@ namespace { // evaluate_common() computes terms common to all pieces attack - int evaluate_common(const Position&p, const Bitboard& b, Color us, EvalInfo& ei, - int AttackWeight, const Value* mgBonus, const Value* egBonus, - Square s = SQ_NONE, const Value* OutpostBonus = NULL) { + template + int evaluate_common(const Position& p, const Bitboard& b, Color us, EvalInfo& ei, Square s = SQ_NONE) { + + static const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight }; + static const Value* MgBonus[] = { 0, 0, MidgameKnightMobilityBonus, MidgameBishopMobilityBonus, MidgameRookMobilityBonus, MidgameQueenMobilityBonus }; + static const Value* EgBonus[] = { 0, 0, EndgameKnightMobilityBonus, EndgameBishopMobilityBonus, EndgameRookMobilityBonus, EndgameQueenMobilityBonus }; + static const Value* OutpostBonus[] = { 0, 0, KnightOutpostBonus, BishopOutpostBonus, 0, 0 }; Color them = opposite_color(us); + // Update attack info + ei.attackedBy[us][Piece] |= b; + // King attack if (b & ei.kingZone[us]) { ei.kingAttackersCount[us]++; - ei.kingAttackersWeight[us] += AttackWeight; + ei.kingAttackersWeight[us] += AttackWeight[Piece]; Bitboard bb = (b & ei.attackedBy[them][KING]); if (bb) ei.kingAdjacentZoneAttacksCount[us] += count_1s_max_15(bb); } + // Remove squares protected by enemy pawns + Bitboard bb = (b & ~ei.attackedBy[them][PAWN]); + // Mobility - int mob = count_1s_max_15(b & ~p.pieces_of_color(us)); - ei.mgMobility += Sign[us] * mgBonus[mob]; - ei.egMobility += Sign[us] * egBonus[mob]; + int mob = (Piece != QUEEN ? count_1s_max_15(bb & ~p.pieces_of_color(us)) + : count_1s(bb & ~p.pieces_of_color(us))); + + ei.mgMobility += Sign[us] * MgBonus[Piece][mob]; + ei.egMobility += Sign[us] * EgBonus[Piece][mob]; // Bishop and Knight outposts - if (!OutpostBonus || !p.square_is_weak(s, them)) + if ( (Piece != BISHOP && Piece != KNIGHT) // compile time condition + || !p.square_is_weak(s, them)) return mob; // Initial bonus based on square Value v, bonus; - v = bonus = OutpostBonus[relative_square(us, s)]; + v = bonus = OutpostBonus[Piece][relative_square(us, s)]; // Increase bonus if supported by pawn, especially if the opponent has // no minor piece which can exchange the outpost piece @@ -580,121 +592,101 @@ namespace { } - // evaluate_knight() assigns bonuses and penalties to a knight of a given - // color on a given square. - - void evaluate_knight(const Position &p, Square s, Color us, EvalInfo &ei) { - - Bitboard b = p.piece_attacks(s); - ei.attackedBy[us][KNIGHT] |= b; - - // King attack, mobility and outposts - evaluate_common(p, b, us, ei, KnightAttackWeight, MidgameKnightMobilityBonus, - EndgameKnightMobilityBonus, s, KnightOutpostBonus); - } - - - // evaluate_bishop() assigns bonuses and penalties to a bishop of a given - // color on a given square. - - void evaluate_bishop(const Position &p, Square s, Color us, EvalInfo &ei) { - - Bitboard b = bishop_attacks_bb(s, p.occupied_squares() & ~p.queens(us)); - ei.attackedBy[us][BISHOP] |= b; - - // King attack, mobility and outposts - evaluate_common(p, b, us, ei, BishopAttackWeight, MidgameBishopMobilityBonus, - EndgameBishopMobilityBonus, s, BishopOutpostBonus); - } - - - // evaluate_rook() assigns bonuses and penalties to a rook of a given - // color on a given square. - - void evaluate_rook(const Position &p, Square s, Color us, EvalInfo &ei) { - - //Bitboard b = p.rook_attacks(s); - Bitboard b = rook_attacks_bb(s, p.occupied_squares() & ~p.rooks_and_queens(us)); - ei.attackedBy[us][ROOK] |= b; + // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given + // color. - // King attack and mobility - int mob = evaluate_common(p, b, us, ei, RookAttackWeight, MidgameRookMobilityBonus, - EndgameRookMobilityBonus); + template + void evaluate_pieces(const Position& pos, Color us, EvalInfo& ei) { - // Rook on 7th rank - Color them = opposite_color(us); - - if ( relative_rank(us, s) == RANK_7 - && relative_rank(us, p.king_square(them)) == RANK_8) - { - ei.mgValue += Sign[us] * MidgameRookOn7thBonus; - ei.egValue += Sign[us] * EndgameRookOn7thBonus; - } + Bitboard b; + Square s, ksq; + Color them; + int mob; + File f; - // Open and half-open files - File f = square_file(s); - if (ei.pi->file_is_half_open(us, f)) + for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++) { - if (ei.pi->file_is_half_open(them, f)) - { - ei.mgValue += Sign[us] * RookOpenFileBonus; - ei.egValue += Sign[us] * RookOpenFileBonus; - } - else - { - ei.mgValue += Sign[us] * RookHalfOpenFileBonus; - ei.egValue += Sign[us] * RookHalfOpenFileBonus; - } - } + s = pos.piece_list(us, Piece, i); - // Penalize rooks which are trapped inside a king. Penalize more if - // king has lost right to castle - if (mob > 6 || ei.pi->file_is_half_open(us, f)) - return; + if (Piece == KNIGHT || Piece == QUEEN) + b = pos.piece_attacks(s); + else if (Piece == BISHOP) + b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.queens(us)); + else if (Piece == ROOK) + b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.rooks_and_queens(us)); - Square ksq = p.king_square(us); + // Attacks, mobility and outposts + mob = evaluate_common(pos, b, us, ei, s); - if ( square_file(ksq) >= FILE_E - && square_file(s) > square_file(ksq) - && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) - { - // Is there a half-open file between the king and the edge of the board? - if (!ei.pi->has_open_file_to_right(us, square_file(ksq))) - ei.mgValue -= p.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2) - : Sign[us] * (TrappedRookPenalty - mob * 16); - } - else if ( square_file(ksq) <= FILE_D - && square_file(s) < square_file(ksq) - && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) - { - // Is there a half-open file between the king and the edge of the board? - if (!ei.pi->has_open_file_to_left(us, square_file(ksq))) - ei.mgValue -= p.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2) - : Sign[us] * (TrappedRookPenalty - mob * 16); - } - } + // Special patterns: trapped bishops on a7/h7/a2/h2 + // and trapped bishops on a1/h1/a8/h8 in Chess960. + if (Piece == BISHOP) + { + if (bit_is_set(MaskA7H7[us], s)) + evaluate_trapped_bishop_a7h7(pos, s, us, ei); + if (Chess960 && bit_is_set(MaskA1H1[us], s)) + evaluate_trapped_bishop_a1h1(pos, s, us, ei); + } - // evaluate_queen() assigns bonuses and penalties to a queen of a given - // color on a given square. + if (Piece == ROOK || Piece == QUEEN) + { + // Queen or rook on 7th rank + them = opposite_color(us); - void evaluate_queen(const Position &p, Square s, Color us, EvalInfo &ei) { + if ( relative_rank(us, s) == RANK_7 + && relative_rank(us, pos.king_square(them)) == RANK_8) + { + ei.mgValue += Sign[us] * (Piece == ROOK ? MidgameRookOn7thBonus : MidgameQueenOn7thBonus); + ei.egValue += Sign[us] * (Piece == ROOK ? EndgameRookOn7thBonus : EndgameQueenOn7thBonus); + } + } - Bitboard b = p.piece_attacks(s); - ei.attackedBy[us][QUEEN] |= b; + // Special extra evaluation for rooks + if (Piece == ROOK) + { + // Open and half-open files + f = square_file(s); + if (ei.pi->file_is_half_open(us, f)) + { + if (ei.pi->file_is_half_open(them, f)) + { + ei.mgValue += Sign[us] * RookOpenFileBonus; + ei.egValue += Sign[us] * RookOpenFileBonus; + } + else + { + ei.mgValue += Sign[us] * RookHalfOpenFileBonus; + ei.egValue += Sign[us] * RookHalfOpenFileBonus; + } + } - // King attack and mobility - evaluate_common(p, b, us, ei, QueenAttackWeight, MidgameQueenMobilityBonus, - EndgameQueenMobilityBonus); + // Penalize rooks which are trapped inside a king. Penalize more if + // king has lost right to castle. + if (mob > 6 || ei.pi->file_is_half_open(us, f)) + continue; - // Queen on 7th rank - Color them = opposite_color(us); + ksq = pos.king_square(us); - if ( relative_rank(us, s) == RANK_7 - && relative_rank(us, p.king_square(them)) == RANK_8) - { - ei.mgValue += Sign[us] * MidgameQueenOn7thBonus; - ei.egValue += Sign[us] * EndgameQueenOn7thBonus; + if ( square_file(ksq) >= FILE_E + && square_file(s) > square_file(ksq) + && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) + { + // Is there a half-open file between the king and the edge of the board? + if (!ei.pi->has_open_file_to_right(us, square_file(ksq))) + ei.mgValue -= pos.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2) + : Sign[us] * (TrappedRookPenalty - mob * 16); + } + else if ( square_file(ksq) <= FILE_D + && square_file(s) < square_file(ksq) + && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) + { + // Is there a half-open file between the king and the edge of the board? + if (!ei.pi->has_open_file_to_left(us, square_file(ksq))) + ei.mgValue -= pos.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2) + : Sign[us] * (TrappedRookPenalty - mob * 16); + } + } } } @@ -703,12 +695,14 @@ namespace { return b >> (num << 3); } - // evaluate_king() assigns bonuses and penalties to a king of a given - // color on a given square. + // evaluate_pieces() assigns bonuses and penalties to a king of a given + // color. - void evaluate_king(const Position &p, Square s, Color us, EvalInfo &ei) { + template<> + void evaluate_pieces(const Position& p, Color us, EvalInfo& ei) { int shelter = 0, sign = Sign[us]; + Square s = p.king_square(us); // King shelter if (relative_rank(us, s) <= RANK_4) @@ -744,14 +738,14 @@ namespace { Bitboard occ = p.occupied_squares(), b, b2; // Initialize the 'attackUnits' variable, which is used later on as an - // index to the SafetyTable[] array. The initial is based on the number - // and types of the attacking pieces, the number of attacked and + // index to the SafetyTable[] array. The initial value is based on the + // number and types of the attacking pieces, the number of attacked and // undefended squares around the king, the square of the king, and the // quality of the pawn shelter. int attackUnits = Min((ei.kingAttackersCount[them] * ei.kingAttackersWeight[them]) / 2, 25) + (ei.kingAdjacentZoneAttacksCount[them] + count_1s_max_15(undefended)) * 3 - + InitKingDanger[relative_square(us, s)] - shelter / 32; + + InitKingDanger[relative_square(us, s)] - (shelter >> 5); // Analyse safe queen contact checks b = undefended & ei.attacked_by(them, QUEEN) & ~p.pieces_of_color(them); @@ -788,8 +782,8 @@ namespace { if ( bit_is_set(p.piece_attacks(from), to) && !bit_is_set(p.pinned_pieces(them), from) && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & p.rooks_and_queens(us)) - && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & p.rooks_and_queens(us))) - + && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & p.bishops_and_queens(us))) + ei.mateThreat[them] = make_move(from, to); } } @@ -797,25 +791,8 @@ namespace { } } } - // Analyse safe rook contact checks: - if (RookContactCheckBonus) - { - b = undefended & ei.attacked_by(them, ROOK) & ~p.pieces_of_color(them); - if (b) - { - Bitboard attackedByOthers = - ei.attacked_by(them, PAWN) | ei.attacked_by(them, KNIGHT) - | ei.attacked_by(them, BISHOP) | ei.attacked_by(them, QUEEN); - - b &= attackedByOthers; - if (b) - { - int count = count_1s_max_15(b); - attackUnits += (RookContactCheckBonus * count * (sente? 2 : 1)); - } - } - } - // Analyse safe distance checks: + + // Analyse safe distance checks if (QueenCheckBonus > 0 || RookCheckBonus > 0) { b = p.piece_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us); @@ -897,141 +874,161 @@ namespace { // evaluate_passed_pawns() evaluates the passed pawns for both sides. void evaluate_passed_pawns(const Position &pos, EvalInfo &ei) { + bool hasUnstoppable[2] = {false, false}; int movesToGo[2] = {100, 100}; - for(Color us = WHITE; us <= BLACK; us++) { - Color them = opposite_color(us); - Square ourKingSq = pos.king_square(us); - Square theirKingSq = pos.king_square(them); - Bitboard b = ei.pi->passed_pawns() & pos.pawns(us), b2, b3, b4; - - while(b) { - Square s = pop_1st_bit(&b); - assert(pos.piece_on(s) == pawn_of_color(us)); - assert(pos.pawn_is_passed(us, s)); - - int r = int(relative_rank(us, s) - RANK_2); - int tr = Max(0, r * (r-1)); - Square blockSq = s + pawn_push(us); - - // Base bonus based on rank: - Value mbonus = Value(20 * tr); - Value ebonus = Value(10 + r * r * 10); - - // Adjust bonus based on king proximity: - ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr); - ebonus -= - Value(square_distance(ourKingSq, blockSq + pawn_push(us)) * 1 * tr); - ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr); - - // If the pawn is free to advance, increase bonus: - if(pos.square_is_empty(blockSq)) { - - b2 = squares_in_front_of(us, s); - b3 = b2 & ei.attacked_by(them); - b4 = b2 & ei.attacked_by(us); - if((b2 & pos.pieces_of_color(them)) == EmptyBoardBB) { - // There are no enemy pieces in the pawn's path! Are any of the - // squares in the pawn's path attacked by the enemy? - if(b3 == EmptyBoardBB) - // No enemy attacks, huge bonus! - ebonus += Value(tr * ((b2 == b4)? 17 : 15)); - else - // OK, there are enemy attacks. Are those squares which are - // attacked by the enemy also attacked by us? If yes, big bonus - // (but smaller than when there are no enemy attacks), if no, - // somewhat smaller bonus. - ebonus += Value(tr * (((b3 & b4) == b3)? 13 : 8)); - } - else { - // There are some enemy pieces in the pawn's path. While this is - // sad, we still assign a moderate bonus if all squares in the path - // which are either occupied by or attacked by enemy pieces are - // also attacked by us. - if(((b3 | (b2 & pos.pieces_of_color(them))) & ~b4) == EmptyBoardBB) - ebonus += Value(tr * 6); - } - // At last, add a small bonus when there are no *friendly* pieces - // in the pawn's path: - if((b2 & pos.pieces_of_color(us)) == EmptyBoardBB) - ebonus += Value(tr); - } + for (Color us = WHITE; us <= BLACK; us++) + { + Color them = opposite_color(us); + Square ourKingSq = pos.king_square(us); + Square theirKingSq = pos.king_square(them); + Bitboard b = ei.pi->passed_pawns() & pos.pawns(us), b2, b3, b4; + + while (b) + { + Square s = pop_1st_bit(&b); + + assert(pos.piece_on(s) == piece_of_color_and_type(us, PAWN)); + assert(pos.pawn_is_passed(us, s)); + + int r = int(relative_rank(us, s) - RANK_2); + int tr = Max(0, r * (r - 1)); + Square blockSq = s + pawn_push(us); + + // Base bonus based on rank + Value mbonus = Value(20 * tr); + Value ebonus = Value(10 + r * r * 10); + + // Adjust bonus based on king proximity + if (tr != 0) + { + ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr); + ebonus -= Value(square_distance(ourKingSq, blockSq + pawn_push(us)) * 1 * tr); + ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr); + + // If the pawn is free to advance, increase bonus + if (pos.square_is_empty(blockSq)) + { + b2 = squares_in_front_of(us, s); + b3 = b2 & ei.attacked_by(them); + b4 = b2 & ei.attacked_by(us); + + // If there is an enemy rook or queen attacking the pawn from behind, + // add all X-ray attacks by the rook or queen. + if ( bit_is_set(ei.attacked_by(them,ROOK) | ei.attacked_by(them,QUEEN),s) + && (squares_behind(us, s) & pos.rooks_and_queens(them))) + b3 = b2; - // If the pawn is supported by a friendly pawn, increase bonus. - b2 = pos.pawns(us) & neighboring_files_bb(s); - if(b2 & rank_bb(s)) - ebonus += Value(r * 20); - else if(pos.pawn_attacks(them, s) & b2) - ebonus += Value(r * 12); - - // If the other side has only a king, check whether the pawn is - // unstoppable: - if(pos.non_pawn_material(them) == Value(0)) { - Square qsq; - int d; - - qsq = relative_square(us, make_square(square_file(s), RANK_8)); - d = square_distance(s, qsq) - square_distance(theirKingSq, qsq) - + ((us == pos.side_to_move())? 0 : 1); - - if(d < 0) { - int mtg = RANK_8 - relative_rank(us, s); - int blockerCount = - count_1s_max_15(squares_in_front_of(us,s)&pos.occupied_squares()); - mtg += blockerCount; - d += blockerCount; - if(d < 0) { - hasUnstoppable[us] = true; - movesToGo[us] = Min(movesToGo[us], mtg); + if ((b2 & pos.pieces_of_color(them)) == EmptyBoardBB) + { + // There are no enemy pieces in the pawn's path! Are any of the + // squares in the pawn's path attacked by the enemy? + if (b3 == EmptyBoardBB) + // No enemy attacks, huge bonus! + ebonus += Value(tr * (b2 == b4 ? 17 : 15)); + else + // OK, there are enemy attacks. Are those squares which are + // attacked by the enemy also attacked by us? If yes, big bonus + // (but smaller than when there are no enemy attacks), if no, + // somewhat smaller bonus. + ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8)); + } + else + { + // There are some enemy pieces in the pawn's path. While this is + // sad, we still assign a moderate bonus if all squares in the path + // which are either occupied by or attacked by enemy pieces are + // also attacked by us. + if (((b3 | (b2 & pos.pieces_of_color(them))) & ~b4) == EmptyBoardBB) + ebonus += Value(tr * 6); + } + // At last, add a small bonus when there are no *friendly* pieces + // in the pawn's path. + if ((b2 & pos.pieces_of_color(us)) == EmptyBoardBB) + ebonus += Value(tr); + } } - } - } - // Rook pawns are a special case: They are sometimes worse, and - // sometimes better than other passed pawns. It is difficult to find - // good rules for determining whether they are good or bad. For now, - // we try the following: Increase the value for rook pawns if the - // other side has no pieces apart from a knight, and decrease the - // value if the other side has a rook or queen. - if(square_file(s) == FILE_A || square_file(s) == FILE_H) { - if(pos.non_pawn_material(them) == KnightValueMidgame - && pos.piece_count(them, KNIGHT) == 1) - ebonus += ebonus / 4; - else if(pos.rooks_and_queens(them)) - ebonus -= ebonus / 4; - } - // Add the scores for this pawn to the middle game and endgame eval. - ei.mgValue += apply_weight(Sign[us] * mbonus, WeightPassedPawnsMidgame); - ei.egValue += apply_weight(Sign[us] * ebonus, WeightPassedPawnsEndgame); - } + // If the pawn is supported by a friendly pawn, increase bonus + b2 = pos.pawns(us) & neighboring_files_bb(s); + if (b2 & rank_bb(s)) + ebonus += Value(r * 20); + else if (pos.pawn_attacks(them, s) & b2) + ebonus += Value(r * 12); + + // If the other side has only a king, check whether the pawn is + // unstoppable + if (pos.non_pawn_material(them) == Value(0)) + { + Square qsq; + int d; + + qsq = relative_square(us, make_square(square_file(s), RANK_8)); + d = square_distance(s, qsq) + - square_distance(theirKingSq, qsq) + + (us != pos.side_to_move()); + + if (d < 0) + { + int mtg = RANK_8 - relative_rank(us, s); + int blockerCount = count_1s_max_15(squares_in_front_of(us,s) & pos.occupied_squares()); + mtg += blockerCount; + d += blockerCount; + if (d < 0) + { + hasUnstoppable[us] = true; + movesToGo[us] = Min(movesToGo[us], mtg); + } + } + } + // Rook pawns are a special case: They are sometimes worse, and + // sometimes better than other passed pawns. It is difficult to find + // good rules for determining whether they are good or bad. For now, + // we try the following: Increase the value for rook pawns if the + // other side has no pieces apart from a knight, and decrease the + // value if the other side has a rook or queen. + if (square_file(s) == FILE_A || square_file(s) == FILE_H) + { + if( pos.non_pawn_material(them) <= KnightValueMidgame + && pos.piece_count(them, KNIGHT) <= 1) + ebonus += ebonus / 4; + else if(pos.rooks_and_queens(them)) + ebonus -= ebonus / 4; + } + + // Add the scores for this pawn to the middle game and endgame eval. + ei.mgValue += apply_weight(Sign[us] * mbonus, WeightPassedPawnsMidgame); + ei.egValue += apply_weight(Sign[us] * ebonus, WeightPassedPawnsEndgame); + } } // Does either side have an unstoppable passed pawn? - if(hasUnstoppable[WHITE] && !hasUnstoppable[BLACK]) - ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]); - else if(hasUnstoppable[BLACK] && !hasUnstoppable[WHITE]) - ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]); - else if(hasUnstoppable[BLACK] && hasUnstoppable[WHITE]) { - // Both sides have unstoppable pawns! Try to find out who queens - // first. We begin by transforming 'movesToGo' to the number of - // plies until the pawn queens for both sides: - movesToGo[WHITE] *= 2; - movesToGo[BLACK] *= 2; - movesToGo[pos.side_to_move()]--; - - // If one side queens at least three plies before the other, that - // side wins: - if(movesToGo[WHITE] <= movesToGo[BLACK] - 3) - ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2)); - else if(movesToGo[BLACK] <= movesToGo[WHITE] - 3) - ei.egValue -= UnstoppablePawnValue - Value(0x40 * (movesToGo[BLACK]/2)); - - // We could also add some rules about the situation when one side - // queens exactly one ply before the other: Does the first queen - // check the opponent's king, or attack the opponent's queening square? - // This is slightly tricky to get right, because it is possible that - // the opponent's king has moved somewhere before the first pawn queens. + if (hasUnstoppable[WHITE] && !hasUnstoppable[BLACK]) + ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]); + else if (hasUnstoppable[BLACK] && !hasUnstoppable[WHITE]) + ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]); + else if (hasUnstoppable[BLACK] && hasUnstoppable[WHITE]) + { + // Both sides have unstoppable pawns! Try to find out who queens + // first. We begin by transforming 'movesToGo' to the number of + // plies until the pawn queens for both sides. + movesToGo[WHITE] *= 2; + movesToGo[BLACK] *= 2; + movesToGo[pos.side_to_move()]--; + + // If one side queens at least three plies before the other, that + // side wins. + if (movesToGo[WHITE] <= movesToGo[BLACK] - 3) + ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2)); + else if(movesToGo[BLACK] <= movesToGo[WHITE] - 3) + ei.egValue -= UnstoppablePawnValue - Value(0x40 * (movesToGo[BLACK]/2)); + + // We could also add some rules about the situation when one side + // queens exactly one ply before the other: Does the first queen + // check the opponent's king, or attack the opponent's queening square? + // This is slightly tricky to get right, because it is possible that + // the opponent's king has moved somewhere before the first pawn queens. } } @@ -1042,14 +1039,13 @@ namespace { void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us, EvalInfo &ei) { - assert(square_is_ok(s)); - assert(pos.piece_on(s) == bishop_of_color(us)); + assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP)); Square b6 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B6 : SQ_G6); Square b8 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B8 : SQ_G8); - if ( pos.piece_on(b6) == pawn_of_color(opposite_color(us)) + if ( pos.piece_on(b6) == piece_of_color_and_type(opposite_color(us), PAWN) && pos.see(s, b6) < 0 && pos.see(s, b8) < 0) { @@ -1066,49 +1062,92 @@ namespace { void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us, EvalInfo &ei) { - Piece pawn = pawn_of_color(us); + Piece pawn = piece_of_color_and_type(us, PAWN); Square b2, b3, c3; assert(Chess960); assert(square_is_ok(s)); - assert(pos.piece_on(s) == bishop_of_color(us)); + assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP)); - if(square_file(s) == FILE_A) { - b2 = relative_square(us, SQ_B2); - b3 = relative_square(us, SQ_B3); - c3 = relative_square(us, SQ_C3); + if (square_file(s) == FILE_A) + { + b2 = relative_square(us, SQ_B2); + b3 = relative_square(us, SQ_B3); + c3 = relative_square(us, SQ_C3); + } + else + { + b2 = relative_square(us, SQ_G2); + b3 = relative_square(us, SQ_G3); + c3 = relative_square(us, SQ_F3); } - else { - b2 = relative_square(us, SQ_G2); - b3 = relative_square(us, SQ_G3); - c3 = relative_square(us, SQ_F3); + + if (pos.piece_on(b2) == pawn) + { + Value penalty; + + if (!pos.square_is_empty(b3)) + penalty = 2*TrappedBishopA1H1Penalty; + else if (pos.piece_on(c3) == pawn) + penalty = TrappedBishopA1H1Penalty; + else + penalty = TrappedBishopA1H1Penalty / 2; + + ei.mgValue -= Sign[us] * penalty; + ei.egValue -= Sign[us] * penalty; } + } - if(pos.piece_on(b2) == pawn) { - Value penalty; - if(!pos.square_is_empty(b3)) - penalty = 2*TrappedBishopA1H1Penalty; - else if(pos.piece_on(c3) == pawn) - penalty = TrappedBishopA1H1Penalty; - else - penalty = TrappedBishopA1H1Penalty / 2; + // evaluate_space() computes the space evaluation for a given side. The + // space evaluation is a simple bonus based on the number of safe squares + // available for minor pieces on the central four files on ranks 2--4. Safe + // squares one, two or three squares behind a friendly pawn are counted + // twice. Finally, the space bonus is scaled by a weight taken from the + // material hash table. + + void evaluate_space(const Position &pos, Color us, EvalInfo &ei) { + + Color them = opposite_color(us); + + // Find the safe squares for our pieces inside the area defined by + // SpaceMask[us]. A square is unsafe it is attacked by an enemy + // pawn, or if it is undefended and attacked by an enemy piece. + + Bitboard safeSquares = SpaceMask[us] + & ~pos.pawns(us) + & ~ei.attacked_by(them, PAWN) + & ~(~ei.attacked_by(us) & ei.attacked_by(them)); - ei.mgValue -= Sign[us] * penalty; - ei.egValue -= Sign[us] * penalty; + // Find all squares which are at most three squares behind some friendly + // pawn. + Bitboard behindFriendlyPawns = pos.pawns(us); + if (us == WHITE) + { + behindFriendlyPawns |= (behindFriendlyPawns >> 8); + behindFriendlyPawns |= (behindFriendlyPawns >> 16); } + else + { + behindFriendlyPawns |= (behindFriendlyPawns << 8); + behindFriendlyPawns |= (behindFriendlyPawns << 16); + } + + int space = count_1s_max_15(safeSquares) + + count_1s_max_15(behindFriendlyPawns & safeSquares); + ei.mgValue += Sign[us] * apply_weight(Value(space * ei.mi->space_weight()), WeightSpace); } - // apply_weight applies an evaluation weight to a value. + // apply_weight() applies an evaluation weight to a value inline Value apply_weight(Value v, int w) { return (v*w) / 0x100; } - // scale_by_game_phase interpolates between a middle game and an endgame + // scale_by_game_phase() interpolates between a middle game and an endgame // score, based on game phase. It also scales the return value by a // ScaleFactor array. @@ -1138,6 +1177,7 @@ namespace { // an UCI-configurable weight with an internal weight. int compute_weight(int uciWeight, int internalWeight) { + uciWeight = (uciWeight * 0x100) / 100; return (uciWeight * internalWeight) / 0x100; } @@ -1156,7 +1196,6 @@ namespace { void init_safety() { QueenContactCheckBonus = get_option_value_int("Queen Contact Check Bonus"); - RookContactCheckBonus = get_option_value_int("Rook Contact Check Bonus"); QueenCheckBonus = get_option_value_int("Queen Check Bonus"); RookCheckBonus = get_option_value_int("Rook Check Bonus"); BishopCheckBonus = get_option_value_int("Bishop Check Bonus"); @@ -1191,5 +1230,4 @@ namespace { SafetyTable[i] = Value(peak); } } - }