/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, 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
Pawns::Entry* pi;
// attackedBy[color][piece type] is a bitboard representing all squares
- // attacked by a given color and piece type, attackedBy[color][0] contains
- // all squares attacked by the given color.
+ // attacked by a given color and piece type, attackedBy[color][ALL_PIECES]
+ // contains all squares attacked by the given color.
Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
// kingRing[color] is the zone around the king which is considered
const int GrainSize = 8;
// Evaluation weights, initialized from UCI options
- enum { Mobility, PassedPawns, Space };
- Score Weights[3];
+ enum { Mobility, PassedPawns, Space, KingDangerUs, KingDangerThem };
+ Score Weights[6];
typedef Value V;
#define S(mg, eg) make_score(mg, eg)
//
// Values modified by Joona Kiiski
const Score WeightsInternal[] = {
- S(252, 344), S(216, 266), S(46, 0)
+ S(289, 344), S(221, 273), S(46, 0), S(271, 0), S(307, 0)
};
// MobilityBonus[PieceType][attacked] contains mobility bonuses for middle and
#undef S
- const Score BishopPinBonus = make_score(66, 11);
-
- // Bonus for having the side to move (modified by Joona Kiiski)
const Score Tempo = make_score(24, 11);
- // Rooks and queens on the 7th rank
- const Score RookOn7thBonus = make_score(3, 20);
- const Score QueenOn7thBonus = make_score(1, 8);
-
- // Rooks and queens attacking pawns on the same rank
- const Score RookOnPawnBonus = make_score(3, 48);
- const Score QueenOnPawnBonus = make_score(1, 40);
-
- // Rooks on open files (modified by Joona Kiiski)
- const Score RookOpenFileBonus = make_score(43, 21);
- const Score RookHalfOpenFileBonus = make_score(19, 10);
-
- // Penalty for rooks trapped inside a friendly king which has lost the
- // right to castle.
- const Value TrappedRookPenalty = Value(180);
+ const Score BishopPinBonus = make_score(66, 11);
+ const Score RookOn7thBonus = make_score(11, 20);
+ const Score QueenOn7thBonus = make_score( 3, 8);
+ const Score RookOnPawnBonus = make_score(10, 28);
+ const Score QueenOnPawnBonus = make_score( 4, 20);
+ const Score RookOpenFileBonus = make_score(43, 21);
+ const Score RookHalfOpenFileBonus = make_score(19, 10);
+ const Score BishopPawnsPenalty = make_score(8, 12);
+ const Score UndefendedMinorPenalty = make_score(25, 10);
+ const Score TrappedRookPenalty = make_score(90, 0);
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
// happen in Chess960 games.
- const Score TrappedBishopA1H1Penalty = make_score(100, 100);
-
- // Penalty for an undefended bishop or knight
- const Score UndefendedMinorPenalty = make_score(25, 10);
+ const Score TrappedBishopA1H1Penalty = make_score(50, 50);
// The SpaceMask[Color] contains the area of the board which is considered
// by the space evaluation. In the middle game, each side is given a bonus
// the strength of the enemy attack are added up into an integer, which
// is used as an index to KingDangerTable[].
//
- // King safety evaluation is asymmetrical and different for us (root color)
- // and for our opponent. These values are used to init KingDangerTable.
- const int KingDangerWeights[] = { 259, 247 };
-
// KingAttackWeights[PieceType] contains king attack weights by piece type
const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
void init() {
- Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
- Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
- Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
-
- int KingDanger[] = { KingDangerWeights[0], KingDangerWeights[1] };
-
- // If running in analysis mode, make sure we use symmetrical king safety.
- // We do so by replacing both KingDanger weights by their average.
- if (Options["UCI_AnalyseMode"])
- KingDanger[0] = KingDanger[1] = (KingDanger[0] + KingDanger[1]) / 2;
+ Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
+ Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "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;
{
t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope));
- KingDangerTable[0][i] = apply_weight(make_score(t, 0), make_score(KingDanger[0], 0));
- KingDangerTable[1][i] = apply_weight(make_score(t, 0), make_score(KingDanger[1], 0));
+ KingDangerTable[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]);
+ KingDangerTable[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]);
}
}
// Init king safety tables only if we are going to use them
if ( pos.piece_count(Us, QUEEN)
- && pos.non_pawn_material(Us) >= QueenValueMg + RookValueMg)
+ && pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg)
{
ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
b &= ei.attackedBy[Us][PAWN];
Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
Bitboard b;
- Square s, ksq;
- int mob;
- File f;
+ Square s;
Score score = SCORE_ZERO;
const Color Them = (Us == WHITE ? BLACK : WHITE);
while ((s = *pl++) != SQ_NONE)
{
// Find attacked squares, including x-ray attacks for bishops and rooks
- if (Piece == KNIGHT || Piece == QUEEN)
- b = pos.attacks_from<Piece>(s);
- else if (Piece == BISHOP)
- b = attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(Us, QUEEN));
- else if (Piece == ROOK)
- b = attacks_bb<ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN));
- else
- assert(false);
+ b = Piece == BISHOP ? attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(Us, QUEEN))
+ : Piece == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN))
+ : pos.attacks_from<Piece>(s);
ei.attackedBy[Us][Piece] |= b;
ei.kingAdjacentZoneAttacksCount[Us] += popcount<Max15>(bb);
}
- mob = (Piece != QUEEN ? popcount<Max15>(b & mobilityArea)
- : popcount<Full >(b & mobilityArea));
-
+ int mob = popcount<Piece == QUEEN ? Full : Max15>(b & mobilityArea);
mobility += MobilityBonus[Piece][mob];
// Decrease score if we are attacked by an enemy pawn. Remaining part
// of threat evaluation must be done later when we have full attack info.
if (ei.attackedBy[Them][PAWN] & s)
score -= ThreatenedByPawnPenalty[Piece];
- else if (Piece == BISHOP && (PseudoAttacks[Piece][pos.king_square(Them)] & s)) {
- const Bitboard between = BetweenBB[s][pos.king_square(Them)] & pos.pieces();
- if (!more_than_one(between))
+
+ // Otherwise give a bonus if we are a bishop and can pin a piece or can
+ // give a discovered check through an x-ray attack.
+ else if ( Piece == BISHOP
+ && (PseudoAttacks[Piece][pos.king_square(Them)] & s)
+ && !more_than_one(BetweenBB[s][pos.king_square(Them)] & pos.pieces()))
score += BishopPinBonus;
- }
+
+ // Penalty for bishop with same coloured pawns
+ if (Piece == BISHOP)
+ score -= BishopPawnsPenalty * ei.pi->pawns_on_same_color_squares(Us, s);
// Bishop and knight outposts squares
if ( (Piece == BISHOP || Piece == KNIGHT)
&& !(pos.pieces(Them, PAWN) & attack_span_mask(Us, s)))
score += evaluate_outposts<Piece, Us>(pos, ei, s);
- if ((Piece == ROOK || Piece == QUEEN) && relative_rank(Us, s) >= RANK_5)
+ if ( (Piece == ROOK || Piece == QUEEN)
+ && relative_rank(Us, s) >= RANK_5)
{
- // Major piece on 7th rank
+ // Major piece 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 ? RookOn7thBonus : QueenOn7thBonus);
+ score += Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus;
- // Major piece attacking pawns on the same rank
+ // Major piece attacking enemy pawns on the same rank
Bitboard pawns = pos.pieces(Them, PAWN) & rank_bb(s);
if (pawns)
- score += (Piece == ROOK ? RookOnPawnBonus
- : QueenOnPawnBonus) * popcount<Max15>(pawns);
- }
-
- // Special extra evaluation for bishops
- if (Piece == BISHOP && pos.is_chess960())
- {
- // 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 (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))
- {
- Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
- if (pos.piece_on(s + d) == make_piece(Us, PAWN))
- {
- if (!pos.is_empty(s + d + pawn_push(Us)))
- score -= 2*TrappedBishopA1H1Penalty;
- else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN))
- score -= TrappedBishopA1H1Penalty;
- else
- score -= TrappedBishopA1H1Penalty / 2;
- }
- }
+ score += popcount<Max15>(pawns) * (Piece == ROOK ? RookOnPawnBonus : QueenOnPawnBonus);
}
// Special extra evaluation for rooks
if (Piece == ROOK)
{
- // Open and half-open files
- f = file_of(s);
- if (ei.pi->file_is_half_open(Us, f))
- {
- if (ei.pi->file_is_half_open(Them, f))
- score += RookOpenFileBonus;
- else
- score += RookHalfOpenFileBonus;
- }
+ // Give a bonus for a rook on a open or half-open file
+ if (ei.pi->half_open(Us, file_of(s)))
+ score += ei.pi->half_open(Them, file_of(s)) ? RookOpenFileBonus
+ : RookHalfOpenFileBonus;
+ if (mob > 6 || ei.pi->half_open(Us, file_of(s)))
+ continue;
+
+ Square ksq = pos.king_square(Us);
// 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;
-
- ksq = pos.king_square(Us);
+ 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->half_open_on_side(Us, file_of(ksq), file_of(ksq) < FILE_E))
+ score -= (TrappedRookPenalty - make_score(mob * 8, 0)) * (pos.can_castle(Us) ? 1 : 2);
+ }
- if ( file_of(ksq) >= FILE_E
- && file_of(s) > file_of(ksq)
- && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(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, file_of(ksq)))
- score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
- : (TrappedRookPenalty - mob * 16), 0);
- }
- else if ( file_of(ksq) <= FILE_D
- && file_of(s) < file_of(ksq)
- && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(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, file_of(ksq)))
- score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
- : (TrappedRookPenalty - mob * 16), 0);
- }
+ // 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
+ && 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.is_empty(s + d + pawn_push(Us)) ? TrappedBishopA1H1Penalty * 4
+ : pos.piece_on(s + d + d) == P ? TrappedBishopA1H1Penalty * 2
+ : TrappedBishopA1H1Penalty;
}
}
Score score = SCORE_ZERO;
// Undefended minors get penalized even if not under attack
- undefendedMinors = pos.pieces(Them)
- & (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
- & ~ei.attackedBy[Them][0];
+ undefendedMinors = pos.pieces(Them, BISHOP, KNIGHT)
+ & ~ei.attackedBy[Them][ALL_PIECES];
if (undefendedMinors)
score += UndefendedMinorPenalty;
// Enemy pieces not defended by a pawn and under our attack
weakEnemies = pos.pieces(Them)
& ~ei.attackedBy[Them][PAWN]
- & ei.attackedBy[Us][0];
+ & ei.attackedBy[Us][ALL_PIECES];
if (!weakEnemies)
return score;
Score score = mobility = SCORE_ZERO;
// 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));
+ const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us, PAWN, KING));
score += evaluate_pieces<KNIGHT, Us, Trace>(pos, ei, mobility, mobilityArea);
score += evaluate_pieces<BISHOP, Us, Trace>(pos, ei, mobility, mobilityArea);
score += evaluate_pieces<QUEEN, Us, Trace>(pos, ei, mobility, mobilityArea);
// Sum up all attacked squares
- ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
- | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
- | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
+ 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];
return score;
}
{
// Find the attacked squares around the king which has no defenders
// apart from the king itself
- undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
+ undefended = ei.attackedBy[Them][ALL_PIECES] & ei.attackedBy[Us][KING];
undefended &= ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
| ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
| ei.attackedBy[Us][QUEEN]);
}
// Analyse enemy's safe distance checks for sliders and knights
- safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]);
+ safe = ~(pos.pieces(Them) | ei.attackedBy[Us][ALL_PIECES]);
b1 = pos.attacks_from<ROOK>(ksq) & safe;
b2 = pos.attacks_from<BISHOP>(ksq) & safe;
if (pos.is_empty(blockSq))
{
squaresToQueen = forward_bb(Us, s);
- defendedSquares = squaresToQueen & ei.attackedBy[Us][0];
+ defendedSquares = squaresToQueen & ei.attackedBy[Us][ALL_PIECES];
// If there is an enemy rook or queen attacking the pawn from behind,
// add all X-ray attacks by the rook or queen. Otherwise consider only
&& (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
unsafeSquares = squaresToQueen;
else
- unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces(Them));
+ unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
- // If there aren't enemy attacks or pieces along the path to queen give
- // huge bonus. Even bigger if we protect the pawn's path.
- if (!unsafeSquares)
- ebonus += Value(rr * (squaresToQueen == defendedSquares ? 17 : 15));
- else
- // OK, there are enemy attacks or pieces (but not pawns). 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(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
+ // If there aren't enemy attacks huge bonus, a bit smaller if at
+ // least block square is not attacked, otherwise smallest bonus.
+ int k = !unsafeSquares ? 15 : !(unsafeSquares & blockSq) ? 9 : 3;
+
+ // Big bonus if the path to queen is fully defended, a bit less
+ // if at least block square is defended.
+ if (defendedSquares == squaresToQueen)
+ k += 6;
+
+ else if (defendedSquares & blockSq)
+ k += (unsafeSquares & defendedSquares) == unsafeSquares ? 4 : 2;
+
+ mbonus += Value(k * rr), ebonus += Value(k * rr);
}
} // rr != 0
// Compute plies to queening and check direct advancement
movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
oppMovesToGo = square_distance(pos.king_square(~c), queeningSquare) - int(c != pos.side_to_move());
- pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
+ pathDefended = ((ei.attackedBy[c][ALL_PIECES] & queeningPath) == queeningPath);
if (movesToGo >= oppMovesToGo && !pathDefended)
continue;
Bitboard safe = SpaceMask[Us]
& ~pos.pieces(Us, PAWN)
& ~ei.attackedBy[Them][PAWN]
- & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]);
+ & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]);
// Find all squares which are at most three squares behind some friendly pawn
Bitboard behind = pos.pieces(Us, PAWN);
projects / stockfish / blobdiff