X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=1d52d30cd9ccdb8f746d11eb10d89ebc26ed3dc4;hp=51d9b4290e6d48b3b324de5e6c459d5fd9d824a2;hb=7bce8831d361317e0cf5156a888ca2d3e568a2ff;hpb=c9dcda6ac488c0058ebd567e1f52e30b8cd0db20 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 51d9b429..1d52d30c 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -31,20 +31,6 @@ namespace { - enum ExtendedPieceType { // Used for tracing - PST = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL - }; - - namespace Tracing { - - Score scores[COLOR_NB][TOTAL + 1]; - std::stringstream stream; - - void add(int idx, Score term_w, Score term_b = SCORE_ZERO); - void row(const char* name, int idx); - std::string do_trace(const Position& pos); - } - // Struct EvalInfo contains various information computed and collected // by the evaluation functions. struct EvalInfo { @@ -87,12 +73,25 @@ namespace { Bitboard pinnedPieces[COLOR_NB]; }; - // Evaluation grain size, must be a power of 2 - const int GrainSize = 4; + namespace Tracing { + + enum Terms { // First 8 entries are for PieceType + PST = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERMS_NB + }; + + Score terms[COLOR_NB][TERMS_NB]; + EvalInfo ei; + ScaleFactor sf; + + double to_cp(Value v); + void add_term(int idx, Score term_w, Score term_b = SCORE_ZERO); + void format_row(std::stringstream& ss, const char* name, int idx); + std::string do_trace(const Position& pos); + } // Evaluation weights, initialized from UCI options enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem }; - Score Weights[6]; + struct Weight { int mg, eg; } Weights[6]; typedef Value V; #define S(mg, eg) make_score(mg, eg) @@ -104,34 +103,33 @@ namespace { // // Values modified by Joona Kiiski const Score WeightsInternal[] = { - S(289, 344), S(233, 201), S(221, 273), S(46, 0), S(271, 0), S(307, 0) + S(289, 344), S(233, 201), S(221, 273), S(46, 0), S(271, 0), S(307, 0) }; // MobilityBonus[PieceType][attacked] contains bonuses for middle and end // game, indexed by piece type and number of attacked squares not occupied by // friendly pieces. const Score MobilityBonus[][32] = { - {}, {}, - { S(-35,-30), S(-22,-20), S(-9,-10), S( 3, 0), S(15, 10), S(27, 20), // Knights - S( 37, 28), S( 42, 31), S(44, 33) }, - { S(-22,-27), S( -8,-13), S( 6, 1), S(20, 15), S(34, 29), S(48, 43), // Bishops - S( 60, 55), S( 68, 63), S(74, 68), S(77, 72), S(80, 75), S(82, 77), - S( 84, 79), S( 86, 81) }, - { S(-17,-33), S(-11,-16), S(-5, 0), S( 1, 16), S( 7, 32), S(13, 48), // Rooks - S( 18, 64), S( 22, 80), S(26, 96), S(29,109), S(31,115), S(33,119), - S( 35,122), S( 36,123), S(37,124) }, - { S(-12,-20), S( -8,-13), S(-5, -7), S(-2, -1), S( 1, 5), S( 4, 11), // Queens - S( 7, 17), S( 10, 23), S(13, 29), S(16, 34), S(18, 38), S(20, 40), - S( 22, 41), S( 23, 41), S(24, 41), S(25, 41), S(25, 41), S(25, 41), - S( 25, 41), S( 25, 41), S(25, 41), S(25, 41), S(25, 41), S(25, 41), - S( 25, 41), S( 25, 41), S(25, 41), S(25, 41) } + {}, {}, + { S(-65,-50), S(-42,-30), S(-9,-10), S( 3, 0), S(15, 10), S(27, 20), // Knights + S( 37, 28), S( 42, 31), S(44, 33) }, + { S(-52,-47), S(-28,-23), S( 6, 1), S(20, 15), S(34, 29), S(48, 43), // Bishops + S( 60, 55), S( 68, 63), S(74, 68), S(77, 72), S(80, 75), S(82, 77), + S( 84, 79), S( 86, 81) }, + { S(-47,-53), S(-31,-26), S(-5, 0), S( 1, 16), S( 7, 32), S(13, 48), // Rooks + S( 18, 64), S( 22, 80), S(26, 96), S(29,109), S(31,115), S(33,119), + S( 35,122), S( 36,123), S(37,124) }, + { S(-42,-40), S(-28,-23), S(-5, -7), S( 0, 0), S( 6, 10), S(11, 19), // Queens + S( 13, 29), S( 18, 38), S(20, 40), S(21, 41), S(22, 41), S(22, 41), + S( 22, 41), S( 23, 41), S(24, 41), S(25, 41), S(25, 41), S(25, 41), + S( 25, 41), S( 25, 41), S(25, 41), S(25, 41), S(25, 41), S(25, 41), + S( 25, 41), S( 25, 41), S(25, 41), S(25, 41) } }; // Outpost[PieceType][Square] contains bonuses for knights and bishops outposts, // indexed by piece type and square (from white's point of view). const Value Outpost[][SQUARE_NB] = { - { - // A B C D E F G H + {// A B C D E F G H V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Knights V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0), @@ -151,7 +149,7 @@ namespace { // type attacks which one. const Score Threat[][PIECE_TYPE_NB] = { { S(0, 0), S( 7, 39), S(24, 49), S(24, 49), S(41,100), S(41,100) }, // Minor - { S(0, 0), S(15, 39), S(15, 45), S(15, 45), S(15, 45), S(24, 49) }, // Major + { S(0, 0), S(15, 39), S(15, 45), S(15, 45), S(15, 45), S(24, 49) } // Major }; // ThreatenedByPawn[PieceType] contains a penalty according to which piece @@ -164,9 +162,7 @@ namespace { const Score Tempo = make_score(24, 11); const Score RookOn7th = make_score(11, 20); - const Score QueenOn7th = make_score( 3, 8); const Score RookOnPawn = make_score(10, 28); - const Score QueenOnPawn = make_score( 4, 20); const Score RookOpenFile = make_score(43, 21); const Score RookSemiopenFile = make_score(19, 10); const Score BishopPawns = make_score( 8, 12); @@ -210,196 +206,37 @@ namespace { // scores, indexed by color and by a calculated integer number. Score KingDanger[COLOR_NB][128]; - // Function prototypes - template - Value do_evaluate(const Position& pos); - - template - void init_eval_info(const Position& pos, EvalInfo& ei); - - template - Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score* mobility); - - template - Score evaluate_king(const Position& pos, const EvalInfo& ei); - - template - Score evaluate_threats(const Position& pos, const EvalInfo& ei); - - template - Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei); - template - int evaluate_space(const Position& pos, const EvalInfo& ei); - - Score evaluate_unstoppable_pawns(const Position& pos, Color us, const EvalInfo& ei); - - Value interpolate(const Score& v, Phase ph, ScaleFactor sf); - Score apply_weight(Score v, Score w); - Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight); - double to_cp(Value v); -} - - -namespace Eval { - - /// evaluate() is the main evaluation function. It always computes two - /// values, an endgame score and a middlegame score, and interpolates - /// between them based on the remaining material. - - Value evaluate(const Position& pos) { - return do_evaluate(pos); + // apply_weight() weighs score 'v' by weight 'w' trying to prevent overflow + Score apply_weight(Score v, const Weight& w) { + return make_score(mg_value(v) * w.mg / 256, eg_value(v) * w.eg / 256); } - /// trace() is like evaluate(), but instead of returning a value, it returns - /// a string (suitable for outputting to stdout) that contains the detailed - /// descriptions and values of each evaluation term. It's mainly used for - /// debugging. - std::string trace(const Position& pos) { - return Tracing::do_trace(pos); - } - - - /// init() computes evaluation weights from the corresponding UCI parameters - /// and setup king tables. - - void init() { - - Weights[Mobility] = weight_option("Mobility (Midgame)", "Mobility (Endgame)", WeightsInternal[Mobility]); - Weights[PawnStructure] = weight_option("Pawn Structure (Midgame)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]); - Weights[PassedPawns] = weight_option("Passed Pawns (Midgame)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]); - Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]); - Weights[KingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]); - Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]); - - const int MaxSlope = 30; - const int Peak = 1280; + // weight_option() computes the value of an evaluation weight, by combining + // two UCI-configurable weights (midgame and endgame) with an internal weight. - for (int t = 0, i = 1; i < 100; ++i) - { - t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope)); + Weight weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) { - KingDanger[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]); - KingDanger[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]); - } + Weight w = { Options[mgOpt] * mg_value(internalWeight) / 100, + Options[egOpt] * eg_value(internalWeight) / 100 }; + return w; } -} // namespace Eval - - -namespace { - -template -Value do_evaluate(const Position& pos) { - - assert(!pos.checkers()); - - EvalInfo ei; - Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO }; - Thread* th = pos.this_thread(); - - // Initialize score by reading the incrementally updated scores included - // in the position object (material + piece square tables) and adding a - // Tempo bonus. Score is computed from the point of view of white. - score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo); - - // Probe the material hash table - ei.mi = Material::probe(pos, th->materialTable, th->endgames); - score += ei.mi->material_value(); - // If we have a specialized evaluation function for the current material - // configuration, call it and return. - if (ei.mi->specialized_eval_exists()) - return ei.mi->evaluate(pos); - - // Probe the pawn hash table - ei.pi = Pawns::probe(pos, th->pawnsTable); - score += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]); - - // Initialize attack and king safety bitboards - init_eval_info(pos, ei); - init_eval_info(pos, ei); - - // Evaluate pieces and mobility - score += evaluate_pieces_of_color(pos, ei, mobility) - - evaluate_pieces_of_color(pos, ei, mobility); - - score += apply_weight(mobility[WHITE] - mobility[BLACK], Weights[Mobility]); - - // Evaluate kings after all other pieces because we need complete attack - // information when computing the king safety evaluation. - score += evaluate_king(pos, ei) - - evaluate_king(pos, ei); - - // Evaluate tactical threats, we need full attack information including king - score += evaluate_threats(pos, ei) - - evaluate_threats(pos, ei); - - // Evaluate passed pawns, we need full attack information including king - score += evaluate_passed_pawns(pos, ei) - - evaluate_passed_pawns(pos, ei); - - // If one side has only a king, score for potential unstoppable pawns - if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK)) - score += evaluate_unstoppable_pawns(pos, WHITE, ei) - - evaluate_unstoppable_pawns(pos, BLACK, ei); - - // Evaluate space for both sides, only in middlegame - if (ei.mi->space_weight()) - { - int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); - score += apply_weight(s * ei.mi->space_weight(), Weights[Space]); - } - - // Scale winning side if position is more drawish than it appears - ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE) - : ei.mi->scale_factor(pos, BLACK); + // interpolate() interpolates between a middlegame and an endgame score, + // based on game phase. It also scales the return value by a ScaleFactor array. - // If we don't already have an unusual scale factor, check for opposite - // colored bishop endgames, and use a lower scale for those. - if ( ei.mi->game_phase() < PHASE_MIDGAME - && pos.opposite_bishops() - && sf == SCALE_FACTOR_NORMAL) - { - // Ignoring any pawns, do both sides only have a single bishop and no - // other pieces? - if ( pos.non_pawn_material(WHITE) == BishopValueMg - && pos.non_pawn_material(BLACK) == BishopValueMg) - { - // Check for KBP vs KB with only a single pawn that is almost - // certainly a draw or at least two pawns. - bool one_pawn = (pos.count(WHITE) + pos.count(BLACK) == 1); - sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32); - } - else - // Endgame with opposite-colored bishops, but also other pieces. Still - // a bit drawish, but not as drawish as with only the two bishops. - sf = ScaleFactor(50); - } + Value interpolate(const Score& v, Phase ph, ScaleFactor sf) { - Value v = interpolate(score, ei.mi->game_phase(), sf); + assert(-VALUE_INFINITE < mg_value(v) && mg_value(v) < VALUE_INFINITE); + assert(-VALUE_INFINITE < eg_value(v) && eg_value(v) < VALUE_INFINITE); + assert(PHASE_ENDGAME <= ph && ph <= PHASE_MIDGAME); - // In case of tracing add all single evaluation contributions for both white and black - if (Trace) - { - Tracing::add(PST, pos.psq_score()); - Tracing::add(IMBALANCE, ei.mi->material_value()); - Tracing::add(PAWN, ei.pi->pawns_value()); - Score w = ei.mi->space_weight() * evaluate_space(pos, ei); - Score b = ei.mi->space_weight() * evaluate_space(pos, ei); - Tracing::add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space])); - Tracing::add(TOTAL, score); - Tracing::stream << "\nScaling: " << std::noshowpos - << std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, " - << std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * " - << std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n" - << "Total evaluation: " << to_cp(v); + int eg = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL; + return Value((mg_value(v) * int(ph) + eg * int(PHASE_MIDGAME - ph)) / PHASE_MIDGAME); } - return pos.side_to_move() == WHITE ? v : -v; -} - // init_eval_info() initializes king bitboards for given color adding // pawn attacks. To be done at the beginning of the evaluation. @@ -413,7 +250,7 @@ Value do_evaluate(const Position& pos) { ei.pinnedPieces[Us] = pos.pinned_pieces(Us); Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(pos.king_square(Them)); - ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us); + ei.attackedBy[Us][ALL_PIECES] = ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us); // Init king safety tables only if we are going to use them if (pos.count(Us) && pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg) @@ -430,15 +267,15 @@ Value do_evaluate(const Position& pos) { // evaluate_outposts() evaluates bishop and knight outpost squares - template + template Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) { const Color Them = (Us == WHITE ? BLACK : WHITE); - assert (Piece == BISHOP || Piece == KNIGHT); + assert (Pt == BISHOP || Pt == KNIGHT); // Initial bonus based on square - Value bonus = Outpost[Piece == BISHOP][relative_square(Us, s)]; + Value bonus = Outpost[Pt == BISHOP][relative_square(Us, s)]; // Increase bonus if supported by pawn, especially if the opponent has // no minor piece which can trade with the outpost piece. @@ -457,62 +294,68 @@ Value do_evaluate(const Position& pos) { // evaluate_pieces() assigns bonuses and penalties to the pieces of a given color - template - Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, Bitboard mobilityArea) { + template + Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, Bitboard* mobilityArea) { Bitboard b; Square s; Score score = SCORE_ZERO; + const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1)); const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square* pl = pos.list(Us); + const Square* pl = pos.list(Us); - ei.attackedBy[Us][Piece] = 0; + ei.attackedBy[Us][Pt] = 0; while ((s = *pl++) != SQ_NONE) { // Find attacked squares, including x-ray attacks for bishops and rooks - b = Piece == BISHOP ? attacks_bb(s, pos.pieces() ^ pos.pieces(Us, QUEEN)) - : Piece == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN)) - : pos.attacks_from(s); + b = Pt == BISHOP ? attacks_bb(s, pos.pieces() ^ pos.pieces(Us, QUEEN)) + : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN)) + : pos.attacks_from(s); if (ei.pinnedPieces[Us] & s) b &= LineBB[pos.king_square(Us)][s]; - ei.attackedBy[Us][Piece] |= b; + ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][Pt] |= b; if (b & ei.kingRing[Them]) { ei.kingAttackersCount[Us]++; - ei.kingAttackersWeight[Us] += KingAttackWeights[Piece]; + ei.kingAttackersWeight[Us] += KingAttackWeights[Pt]; Bitboard bb = b & ei.attackedBy[Them][KING]; if (bb) ei.kingAdjacentZoneAttacksCount[Us] += popcount(bb); } - int mob = Piece != QUEEN ? popcount(b & mobilityArea) - : popcount(b & mobilityArea); + if (Pt == QUEEN) + b &= ~( ei.attackedBy[Them][KNIGHT] + | ei.attackedBy[Them][BISHOP] + | ei.attackedBy[Them][ROOK]); - mobility[Us] += MobilityBonus[Piece][mob]; + int mob = Pt != QUEEN ? popcount(b & mobilityArea[Us]) + : popcount(b & mobilityArea[Us]); + + mobility[Us] += MobilityBonus[Pt][mob]; // Decrease score if we are attacked by an enemy pawn. The remaining part // of threat evaluation must be done later when we have full attack info. if (ei.attackedBy[Them][PAWN] & s) - score -= ThreatenedByPawn[Piece]; + score -= ThreatenedByPawn[Pt]; - // Penalty for bishop with same coloured pawns - if (Piece == BISHOP) - score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s); + if (Pt == BISHOP || Pt == KNIGHT) + { + // Penalty for bishop with same colored pawns + if (Pt == BISHOP) + score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s); - // Penalty for knight when there are few enemy pawns - if (Piece == KNIGHT) - score -= KnightPawns * std::max(5 - pos.count(Them), 0); + // Penalty for knight when there are few enemy pawns + if (Pt == KNIGHT) + score -= KnightPawns * std::max(5 - pos.count(Them), 0); - if (Piece == BISHOP || Piece == KNIGHT) - { // Bishop and knight outposts squares if (!(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s))) - score += evaluate_outposts(pos, ei, s); + score += evaluate_outposts(pos, ei, s); // Bishop or knight behind a pawn if ( relative_rank(Us, s) < RANK_5 @@ -520,28 +363,26 @@ Value do_evaluate(const Position& pos) { score += MinorBehindPawn; } - if ( (Piece == ROOK || Piece == QUEEN) - && relative_rank(Us, s) >= RANK_5) + if (Pt == ROOK) { - // Major piece on 7th rank and enemy king trapped on 8th + // Rook on 7th rank and enemy king trapped on 8th if ( relative_rank(Us, s) == RANK_7 && relative_rank(Us, pos.king_square(Them)) == RANK_8) - score += Piece == ROOK ? RookOn7th : QueenOn7th; + score += RookOn7th; - // Major piece attacking enemy pawns on the same rank/file - Bitboard pawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]; - if (pawns) - score += popcount(pawns) * (Piece == ROOK ? RookOnPawn : QueenOnPawn); - } + // Rook piece attacking enemy pawns on the same rank/file + if (relative_rank(Us, s) >= RANK_5) + { + Bitboard pawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]; + if (pawns) + score += popcount(pawns) * RookOnPawn; + } - // Special extra evaluation for rooks - if (Piece == ROOK) - { // Give a bonus for a rook on a open or semi-open file - if (ei.pi->semiopen(Us, file_of(s))) - score += ei.pi->semiopen(Them, file_of(s)) ? RookOpenFile : RookSemiopenFile; + if (ei.pi->semiopen_file(Us, file_of(s))) + score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOpenFile : RookSemiopenFile; - if (mob > 3 || ei.pi->semiopen(Us, file_of(s))) + if (mob > 3 || ei.pi->semiopen_file(Us, file_of(s))) continue; Square ksq = pos.king_square(Us); @@ -550,58 +391,35 @@ Value do_evaluate(const Position& pos) { // king has lost its castling capability. if ( ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq))) && (rank_of(ksq) == rank_of(s) || relative_rank(Us, ksq) == RANK_1) - && !ei.pi->semiopen_on_side(Us, file_of(ksq), file_of(ksq) < FILE_E)) - score -= (TrappedRook - make_score(mob * 8, 0)) * (pos.can_castle(Us) ? 1 : 2); + && !ei.pi->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq))) + score -= (TrappedRook - make_score(mob * 8, 0)) * (1 + !pos.can_castle(Us)); } // An important Chess960 pattern: A cornered bishop blocked by a friendly // pawn diagonally in front of it is a very serious problem, especially // when that pawn is also blocked. - if ( Piece == BISHOP + if ( Pt == BISHOP && pos.is_chess960() && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))) { - const enum Piece P = make_piece(Us, PAWN); Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W); - if (pos.piece_on(s + d) == P) - score -= !pos.empty(s + d + pawn_push(Us)) ? TrappedBishopA1H1 * 4 - : pos.piece_on(s + d + d) == P ? TrappedBishopA1H1 * 2 - : TrappedBishopA1H1; + if (pos.piece_on(s + d) == make_piece(Us, PAWN)) + score -= !pos.empty(s + d + pawn_push(Us)) ? TrappedBishopA1H1 * 4 + : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? TrappedBishopA1H1 * 2 + : TrappedBishopA1H1; } } if (Trace) - Tracing::scores[Us][Piece] = score; + Tracing::terms[Us][Pt] = score; - return score; + return score - evaluate_pieces(pos, ei, mobility, mobilityArea); } - - // evaluate_pieces_of_color() assigns bonuses and penalties to all the - // pieces of a given color. - - template - Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score* mobility) { - - const Color Them = (Us == WHITE ? BLACK : WHITE); - - // Do not include in mobility squares protected by enemy pawns or occupied by our pieces - const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us, PAWN, KING)); - - Score score = evaluate_pieces(pos, ei, mobility, mobilityArea) - + evaluate_pieces(pos, ei, mobility, mobilityArea) - + evaluate_pieces(pos, ei, mobility, mobilityArea) - + evaluate_pieces(pos, ei, mobility, mobilityArea); - - // Sum up all attacked squares (updated in evaluate_pieces) - ei.attackedBy[Us][ALL_PIECES] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] - | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK] - | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING]; - if (Trace) - Tracing::scores[Us][MOBILITY] = apply_weight(mobility[Us], Weights[Mobility]); - - return score; - } + template<> + Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; } + template<> + Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; } // evaluate_king() assigns bonuses and penalties to a king of a given color @@ -636,6 +454,7 @@ Value do_evaluate(const Position& pos) { // the pawn shelter (current 'score' value). attackUnits = std::min(20, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2) + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount(undefended)) + + 2 * (ei.pinnedPieces[Us] != 0) - mg_value(score) / 32; // Analyse the enemy's safe queen contact checks. Firstly, find the @@ -647,6 +466,7 @@ Value do_evaluate(const Position& pos) { // ...and then remove squares not supported by another enemy piece b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT] | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]); + if (b) attackUnits += QueenContactCheck * popcount(b) @@ -666,6 +486,7 @@ Value do_evaluate(const Position& pos) { // ...and then remove squares not supported by another enemy piece b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT] | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]); + if (b) attackUnits += RookContactCheck * popcount(b) @@ -707,7 +528,7 @@ Value do_evaluate(const Position& pos) { } if (Trace) - Tracing::scores[Us][KING] = score; + Tracing::terms[Us][KING] = score; return score; } @@ -749,7 +570,7 @@ Value do_evaluate(const Position& pos) { } if (Trace) - Tracing::scores[Us][THREAT] = score; + Tracing::terms[Us][Tracing::THREAT] = score; return score; } @@ -790,7 +611,7 @@ Value do_evaluate(const Position& pos) { // If blockSq is not the queening square then consider also a second push if (relative_rank(Us, blockSq) != RANK_8) - ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr); + ebonus -= Value(rr * square_distance(pos.king_square(Us), blockSq + pawn_push(Us))); // If the pawn is free to advance, then increase the bonus if (pos.empty(blockSq)) @@ -858,11 +679,10 @@ Value do_evaluate(const Position& pos) { ebonus += ebonus / 4; score += make_score(mbonus, ebonus); - } if (Trace) - Tracing::scores[Us][PASSED] = apply_weight(score, Weights[PassedPawns]); + Tracing::terms[Us][Tracing::PASSED] = apply_weight(score, Weights[PassedPawns]); // Add the scores to the middlegame and endgame eval return apply_weight(score, Weights[PassedPawns]); @@ -916,104 +736,233 @@ Value do_evaluate(const Position& pos) { } - // interpolate() interpolates between a middlegame and an endgame score, - // based on game phase. It also scales the return value by a ScaleFactor array. + // do_evaluate() is the evaluation entry point, called directly from evaluate() - Value interpolate(const Score& v, Phase ph, ScaleFactor sf) { + template + Value do_evaluate(const Position& pos) { - assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE); - assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE); - assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME); + assert(!pos.checkers()); - int e = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL; - int r = (mg_value(v) * int(ph) + e * int(PHASE_MIDGAME - ph)) / PHASE_MIDGAME; - return Value((r / GrainSize) * GrainSize); // Sign independent - } + EvalInfo ei; + Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO }; + Thread* thisThread = pos.this_thread(); - // apply_weight() weights score v by score w trying to prevent overflow - Score apply_weight(Score v, Score w) { - return make_score((int(mg_value(v)) * mg_value(w)) / 0x100, - (int(eg_value(v)) * eg_value(w)) / 0x100); - } + // Initialize score by reading the incrementally updated scores included + // in the position object (material + piece square tables) and adding a + // Tempo bonus. Score is computed from the point of view of white. + score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo); - // weight_option() computes the value of an evaluation weight, by combining - // two UCI-configurable weights (midgame and endgame) with an internal weight. + // Probe the material hash table + ei.mi = Material::probe(pos, thisThread->materialTable, thisThread->endgames); + score += ei.mi->material_value(); - Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) { + // If we have a specialized evaluation function for the current material + // configuration, call it and return. + if (ei.mi->specialized_eval_exists()) + return ei.mi->evaluate(pos); - // Scale option value from 100 to 256 - int mg = Options[mgOpt] * 256 / 100; - int eg = Options[egOpt] * 256 / 100; + // Probe the pawn hash table + ei.pi = Pawns::probe(pos, thisThread->pawnsTable); + score += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]); - return apply_weight(make_score(mg, eg), internalWeight); + // Initialize attack and king safety bitboards + init_eval_info(pos, ei); + init_eval_info(pos, ei); + + ei.attackedBy[WHITE][ALL_PIECES] |= ei.attackedBy[WHITE][KING]; + ei.attackedBy[BLACK][ALL_PIECES] |= ei.attackedBy[BLACK][KING]; + + // Do not include in mobility squares protected by enemy pawns or occupied by our pieces + Bitboard mobilityArea[] = { ~(ei.attackedBy[BLACK][PAWN] | pos.pieces(WHITE, PAWN, KING)), + ~(ei.attackedBy[WHITE][PAWN] | pos.pieces(BLACK, PAWN, KING)) }; + + // Evaluate pieces and mobility + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + score += apply_weight(mobility[WHITE] - mobility[BLACK], Weights[Mobility]); + + // Evaluate kings after all other pieces because we need complete attack + // information when computing the king safety evaluation. + score += evaluate_king(pos, ei) + - evaluate_king(pos, ei); + + // Evaluate tactical threats, we need full attack information including king + score += evaluate_threats(pos, ei) + - evaluate_threats(pos, ei); + + // Evaluate passed pawns, we need full attack information including king + score += evaluate_passed_pawns(pos, ei) + - evaluate_passed_pawns(pos, ei); + + // If one side has only a king, score for potential unstoppable pawns + if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK)) + score += evaluate_unstoppable_pawns(pos, WHITE, ei) + - evaluate_unstoppable_pawns(pos, BLACK, ei); + + // Evaluate space for both sides, only in middlegame + if (ei.mi->space_weight()) + { + int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); + score += apply_weight(s * ei.mi->space_weight(), Weights[Space]); + } + + // Scale winning side if position is more drawish than it appears + ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE) + : ei.mi->scale_factor(pos, BLACK); + + // If we don't already have an unusual scale factor, check for opposite + // colored bishop endgames, and use a lower scale for those. + if ( ei.mi->game_phase() < PHASE_MIDGAME + && pos.opposite_bishops() + && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN)) + { + // Ignoring any pawns, do both sides only have a single bishop and no + // other pieces? + if ( pos.non_pawn_material(WHITE) == BishopValueMg + && pos.non_pawn_material(BLACK) == BishopValueMg) + { + // Check for KBP vs KB with only a single pawn that is almost + // certainly a draw or at least two pawns. + bool one_pawn = (pos.count(WHITE) + pos.count(BLACK) == 1); + sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32); + } + else + // Endgame with opposite-colored bishops, but also other pieces. Still + // a bit drawish, but not as drawish as with only the two bishops. + sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL); + } + + Value v = interpolate(score, ei.mi->game_phase(), sf); + + // In case of tracing add all single evaluation contributions for both white and black + if (Trace) + { + Tracing::add_term(Tracing::PST, pos.psq_score()); + Tracing::add_term(Tracing::IMBALANCE, ei.mi->material_value()); + Tracing::add_term(PAWN, ei.pi->pawns_value()); + Tracing::add_term(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility]) + , apply_weight(mobility[BLACK], Weights[Mobility])); + Score w = ei.mi->space_weight() * evaluate_space(pos, ei); + Score b = ei.mi->space_weight() * evaluate_space(pos, ei); + Tracing::add_term(Tracing::SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space])); + Tracing::add_term(Tracing::TOTAL, score); + Tracing::ei = ei; + Tracing::sf = sf; + } + + return pos.side_to_move() == WHITE ? v : -v; } - // Tracing functions definitions + // Tracing function definitions - double to_cp(Value v) { return double(v) / double(PawnValueMg); } + double Tracing::to_cp(Value v) { return double(v) / PawnValueEg; } - void Tracing::add(int idx, Score wScore, Score bScore) { + void Tracing::add_term(int idx, Score wScore, Score bScore) { - scores[WHITE][idx] = wScore; - scores[BLACK][idx] = bScore; + terms[WHITE][idx] = wScore; + terms[BLACK][idx] = bScore; } - void Tracing::row(const char* name, int idx) { + void Tracing::format_row(std::stringstream& ss, const char* name, int idx) { - Score wScore = scores[WHITE][idx]; - Score bScore = scores[BLACK][idx]; + Score wScore = terms[WHITE][idx]; + Score bScore = terms[BLACK][idx]; switch (idx) { case PST: case IMBALANCE: case PAWN: case TOTAL: - stream << std::setw(20) << name << " | --- --- | --- --- | " - << std::setw(6) << to_cp(mg_value(wScore)) << " " - << std::setw(6) << to_cp(eg_value(wScore)) << " \n"; + ss << std::setw(20) << name << " | --- --- | --- --- | " + << std::setw(5) << to_cp(mg_value(wScore - bScore)) << " " + << std::setw(5) << to_cp(eg_value(wScore - bScore)) << " \n"; break; default: - stream << std::setw(20) << name << " | " << std::noshowpos - << std::setw(5) << to_cp(mg_value(wScore)) << " " - << std::setw(5) << to_cp(eg_value(wScore)) << " | " - << std::setw(5) << to_cp(mg_value(bScore)) << " " - << std::setw(5) << to_cp(eg_value(bScore)) << " | " - << std::showpos - << std::setw(6) << to_cp(mg_value(wScore - bScore)) << " " - << std::setw(6) << to_cp(eg_value(wScore - bScore)) << " \n"; + ss << std::setw(20) << name << " | " << std::noshowpos + << std::setw(5) << to_cp(mg_value(wScore)) << " " + << std::setw(5) << to_cp(eg_value(wScore)) << " | " + << std::setw(5) << to_cp(mg_value(bScore)) << " " + << std::setw(5) << to_cp(eg_value(bScore)) << " | " + << std::setw(5) << to_cp(mg_value(wScore - bScore)) << " " + << std::setw(5) << to_cp(eg_value(wScore - bScore)) << " \n"; } } std::string Tracing::do_trace(const Position& pos) { - stream.str(""); - stream << std::showpoint << std::showpos << std::fixed << std::setprecision(2); - std::memset(scores, 0, 2 * (TOTAL + 1) * sizeof(Score)); - - do_evaluate(pos); - - std::string totals = stream.str(); - stream.str(""); - - stream << std::setw(21) << "Eval term " << "| White | Black | Total \n" - << " | MG EG | MG EG | MG EG \n" - << "---------------------+-------------+-------------+---------------\n"; - - row("Material, PST, Tempo", PST); - row("Material imbalance", IMBALANCE); - row("Pawns", PAWN); - row("Knights", KNIGHT); - row("Bishops", BISHOP); - row("Rooks", ROOK); - row("Queens", QUEEN); - row("Mobility", MOBILITY); - row("King safety", KING); - row("Threats", THREAT); - row("Passed pawns", PASSED); - row("Space", SPACE); - - stream << "---------------------+-------------+-------------+---------------\n"; - row("Total", TOTAL); - stream << totals; - - return stream.str(); + std::memset(terms, 0, sizeof(terms)); + + Value v = do_evaluate(pos); + v = pos.side_to_move() == WHITE ? v : -v; // White's point of view + + std::stringstream ss; + ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2) + << " Eval term | White | Black | Total \n" + << " | MG EG | MG EG | MG EG \n" + << "---------------------+-------------+-------------+-------------\n"; + + format_row(ss, "Material, PST, Tempo", PST); + format_row(ss, "Material imbalance", IMBALANCE); + format_row(ss, "Pawns", PAWN); + format_row(ss, "Knights", KNIGHT); + format_row(ss, "Bishops", BISHOP); + format_row(ss, "Rooks", ROOK); + format_row(ss, "Queens", QUEEN); + format_row(ss, "Mobility", MOBILITY); + format_row(ss, "King safety", KING); + format_row(ss, "Threats", THREAT); + format_row(ss, "Passed pawns", PASSED); + format_row(ss, "Space", SPACE); + + ss << "---------------------+-------------+-------------+-------------\n"; + format_row(ss, "Total", TOTAL); + + ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n"; + + return ss.str(); + } + +} // namespace + + +namespace Eval { + + /// evaluate() is the main evaluation function. It returns a static evaluation + /// of the position always from the point of view of the side to move. + + Value evaluate(const Position& pos) { + return do_evaluate(pos); + } + + + /// trace() is like evaluate(), but instead of returning a value, it returns + /// a string (suitable for outputting to stdout) that contains the detailed + /// descriptions and values of each evaluation term. It's mainly used for + /// debugging. + std::string trace(const Position& pos) { + return Tracing::do_trace(pos); + } + + + /// init() computes evaluation weights from the corresponding UCI parameters + /// and setup king tables. + + void init() { + + Weights[Mobility] = weight_option("Mobility (Midgame)", "Mobility (Endgame)", WeightsInternal[Mobility]); + Weights[PawnStructure] = weight_option("Pawn Structure (Midgame)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]); + Weights[PassedPawns] = weight_option("Passed Pawns (Midgame)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]); + Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]); + Weights[KingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]); + Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]); + + const int MaxSlope = 30; + const int Peak = 1280; + + for (int t = 0, i = 1; i < 100; ++i) + { + t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope)); + + KingDanger[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]); + KingDanger[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]); + } } -} + +} // namespace Eval