// game, indexed by piece type and number of attacked squares in the MobilityArea.
const Score MobilityBonus[][32] = {
{}, {},
- { S(-75,-76), S(-56,-54), S(- 9,-26), S( -2,-10), S( 6, 5), S( 15, 11), // Knights
+ { S(-75,-76), S(-56,-54), S( -9,-26), S( -2,-10), S( 6, 5), S( 15, 11), // Knights
S( 22, 26), S( 30, 28), S( 36, 29) },
{ S(-48,-58), S(-21,-19), S( 16, -2), S( 26, 12), S( 37, 22), S( 51, 42), // Bishops
S( 54, 54), S( 63, 58), S( 65, 63), S( 71, 70), S( 79, 74), S( 81, 86),
// ThreatBySafePawn[PieceType] contains bonuses according to which piece
// type is attacked by a pawn which is protected or is not attacked.
const Score ThreatBySafePawn[PIECE_TYPE_NB] = {
- S(0, 0), S(0, 0), S(176, 139), S(131, 127), S(217, 218), S(203, 215) };
+ S(0, 0), S(0, 0), S(176, 139), S(131, 127), S(217, 218), S(203, 215)
+ };
// Threat[by minor/by rook][attacked PieceType] contains
// bonuses according to which piece type attacks which one.
const Score BishopPawns = S( 8, 12);
const Score RookOnPawn = S( 8, 24);
const Score TrappedRook = S(92, 0);
+ const Score CloseEnemies = S( 7, 0);
const Score SafeCheck = S(20, 20);
const Score OtherCheck = S(10, 10);
const Score ThreatByHangingPawn = S(71, 61);
const Score Hanging = S(48, 27);
const Score ThreatByPawnPush = S(38, 22);
const Score Unstoppable = S( 0, 20);
+ const Score PawnlessFlank = S(20, 80);
+ const Score HinderPassedPawn = S( 7, 0);
+ const Score ThreatByRank = S(16, 3);
// 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
#undef S
#undef V
- // King danger constants and variables. The king danger scores are looked-up
- // in KingDanger[]. Various little "meta-bonuses" measuring the strength
- // of the enemy attack are added up into an integer, which is used as an
- // index to KingDanger[].
- Score KingDanger[512];
-
// KingAttackWeights[PieceType] contains king attack weights by piece type
- const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 7, 5, 4, 1 };
+ const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 78, 56, 45, 11 };
// Penalties for enemy's safe checks
- const int QueenContactCheck = 89;
- const int QueenCheck = 62;
- const int RookCheck = 57;
- const int BishopCheck = 48;
- const int KnightCheck = 78;
+ const int QueenContactCheck = 997;
+ const int QueenCheck = 695;
+ const int RookCheck = 638;
+ const int BishopCheck = 538;
+ const int KnightCheck = 874;
// eval_init() initializes king and attack bitboards for a given color
template<Color Us>
void eval_init(const Position& pos, EvalInfo& ei) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square Down = (Us == WHITE ? DELTA_S : DELTA_N);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Square Down = (Us == WHITE ? SOUTH : NORTH);
ei.pinnedPieces[Us] = pos.pinned_pieces(Us);
Bitboard b = ei.attackedBy[Them][KING];
// Init king safety tables only if we are going to use them
if (pos.non_pawn_material(Us) >= QueenValueMg)
{
- ei.kingRing[Them] = b | shift_bb<Down>(b);
+ ei.kingRing[Them] = b | shift<Down>(b);
b &= ei.attackedBy[Us][PAWN];
ei.kingAttackersCount[Us] = popcount(b);
ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
&& pos.is_chess960()
&& (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);
+ Square d = pawn_push(Us) + (file_of(s) == FILE_A ? EAST : WEST);
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
if (Pt == QUEEN)
{
// Penalty if any relative pin or discovered attack against the queen
- if (pos.slider_blockers(pos.pieces(), pos.pieces(Them, ROOK, BISHOP), s))
+ Bitboard pinners;
+ if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s, pinners))
score -= WeakQueen;
}
}
// evaluate_king() assigns bonuses and penalties to a king of a given color
+ const Bitboard WhiteCamp = Rank1BB | Rank2BB | Rank3BB | Rank4BB | Rank5BB;
+ const Bitboard BlackCamp = Rank8BB | Rank7BB | Rank6BB | Rank5BB | Rank4BB;
+ const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB;
+ const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
+ const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB;
+
+ const Bitboard KingFlank[COLOR_NB][FILE_NB] = {
+ { QueenSide & WhiteCamp, QueenSide & WhiteCamp, QueenSide & WhiteCamp, CenterFiles & WhiteCamp,
+ CenterFiles & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp },
+ { QueenSide & BlackCamp, QueenSide & BlackCamp, QueenSide & BlackCamp, CenterFiles & BlackCamp,
+ CenterFiles & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp },
+ };
+
template<Color Us, bool DoTrace>
Score evaluate_king(const Position& pos, const EvalInfo& ei) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square Up = (Us == WHITE ? DELTA_N : DELTA_S);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Square Up = (Us == WHITE ? NORTH : SOUTH);
Bitboard undefended, b, b1, b2, safe, other;
- int attackUnits;
+ int kingDanger;
const Square ksq = pos.square<KING>(Us);
// King shelter and enemy pawns storm
b = ei.attackedBy[Them][ALL_PIECES] & ~ei.attackedBy[Us][ALL_PIECES]
& ei.kingRing[Us] & ~pos.pieces(Them);
- // Initialize the 'attackUnits' variable, which is used later on as an
- // index into the KingDanger[] array. The initial value is based on the
+ // Initialize the 'kingDanger' variable, which will be transformed
+ // later into a king danger score. The initial value is based on the
// number and types of the enemy's attacking pieces, the number of
// attacked and undefended squares around our king and the quality of
// the pawn shelter (current 'score' value).
- attackUnits = std::min(72, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them])
- + 9 * ei.kingAdjacentZoneAttacksCount[Them]
- + 21 * popcount(undefended)
- + 12 * (popcount(b) + !!ei.pinnedPieces[Us])
- - 64 * !pos.count<QUEEN>(Them)
- - mg_value(score) / 8;
+ kingDanger = std::min(807, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them])
+ + 101 * ei.kingAdjacentZoneAttacksCount[Them]
+ + 235 * popcount(undefended)
+ + 134 * (popcount(b) + !!ei.pinnedPieces[Us])
+ - 717 * !pos.count<QUEEN>(Them)
+ - 7 * mg_value(score) / 5 - 5;
// Analyse the enemy's safe queen contact checks. Firstly, find the
// undefended squares around the king reachable by the enemy queen...
b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
// ...and keep squares supported by another enemy piece
- attackUnits += QueenContactCheck * popcount(b & ei.attackedBy2[Them]);
+ kingDanger += QueenContactCheck * popcount(b & ei.attackedBy2[Them]);
// Analyse the safe enemy's checks which are possible on next move...
safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them));
// ... and some other potential checks, only requiring the square to be
// safe from pawn-attacks, and not being occupied by a blocked pawn.
other = ~( ei.attackedBy[Us][PAWN]
- | (pos.pieces(Them, PAWN) & shift_bb<Up>(pos.pieces(PAWN))));
+ | (pos.pieces(Them, PAWN) & shift<Up>(pos.pieces(PAWN))));
b1 = pos.attacks_from<ROOK >(ksq);
b2 = pos.attacks_from<BISHOP>(ksq);
// Enemy queen safe checks
if ((b1 | b2) & ei.attackedBy[Them][QUEEN] & safe)
- attackUnits += QueenCheck, score -= SafeCheck;
+ kingDanger += QueenCheck, score -= SafeCheck;
// For other pieces, also consider the square safe if attacked twice,
// and only defended by a queen.
// Enemy rooks safe and other checks
if (b1 & ei.attackedBy[Them][ROOK] & safe)
- attackUnits += RookCheck, score -= SafeCheck;
+ kingDanger += RookCheck, score -= SafeCheck;
else if (b1 & ei.attackedBy[Them][ROOK] & other)
score -= OtherCheck;
// Enemy bishops safe and other checks
if (b2 & ei.attackedBy[Them][BISHOP] & safe)
- attackUnits += BishopCheck, score -= SafeCheck;
+ kingDanger += BishopCheck, score -= SafeCheck;
else if (b2 & ei.attackedBy[Them][BISHOP] & other)
score -= OtherCheck;
// Enemy knights safe and other checks
b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT];
if (b & safe)
- attackUnits += KnightCheck, score -= SafeCheck;
+ kingDanger += KnightCheck, score -= SafeCheck;
else if (b & other)
score -= OtherCheck;
- // Finally, extract the king danger score from the KingDanger[]
- // array and subtract the score from the evaluation.
- score -= KingDanger[std::max(std::min(attackUnits, 399), 0)];
+ // Compute the king danger score and subtract it from the evaluation
+ if (kingDanger > 0)
+ score -= make_score(std::min(kingDanger * kingDanger / 4096, 2 * int(BishopValueMg)), 0);
}
+ // King tropism: firstly, find squares that opponent attacks in our king flank
+ File kf = file_of(ksq);
+ b = ei.attackedBy[Them][ALL_PIECES] & KingFlank[Us][kf];
+
+ assert(((Us == WHITE ? b << 4 : b >> 4) & b) == 0);
+ assert(popcount(Us == WHITE ? b << 4 : b >> 4) == popcount(b));
+
+ // Secondly, add the squares which are attacked twice in that flank and
+ // which are not defended by our pawns.
+ b = (Us == WHITE ? b << 4 : b >> 4)
+ | (b & ei.attackedBy2[Them] & ~ei.attackedBy[Us][PAWN]);
+
+ score -= CloseEnemies * popcount(b);
+
+ // Penalty when our king is on a pawnless flank
+ if (!(pos.pieces(PAWN) & (KingFlank[WHITE][kf] | KingFlank[BLACK][kf])))
+ score -= PawnlessFlank;
+
if (DoTrace)
Trace::add(KING, Us, score);
// evaluate_threats() assigns bonuses according to the types of the attacking
// and the attacked pieces.
- const Bitboard WhiteCamp = Rank1BB | Rank2BB | Rank3BB | Rank4BB | Rank5BB;
- const Bitboard BlackCamp = Rank8BB | Rank7BB | Rank6BB | Rank5BB | Rank4BB;
- const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB;
- const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
- const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB;
-
- const Bitboard KingFlank[COLOR_NB][FILE_NB] = {
- { QueenSide & WhiteCamp, QueenSide & WhiteCamp, QueenSide & WhiteCamp, CenterFiles & WhiteCamp,
- CenterFiles & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp },
- { QueenSide & BlackCamp, QueenSide & BlackCamp, QueenSide & BlackCamp, CenterFiles & BlackCamp,
- CenterFiles & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp },
- };
-
template<Color Us, bool DoTrace>
Score evaluate_threats(const Position& pos, const EvalInfo& ei) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square Up = (Us == WHITE ? DELTA_N : DELTA_S);
- const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE);
- const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
- const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB);
- const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Square Up = (Us == WHITE ? NORTH : SOUTH);
+ const Square Left = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
+ const Square Right = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
+ const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB);
+ const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
enum { Minor, Rook };
b = pos.pieces(Us, PAWN) & ( ~ei.attackedBy[Them][ALL_PIECES]
| ei.attackedBy[Us][ALL_PIECES]);
- safeThreats = (shift_bb<Right>(b) | shift_bb<Left>(b)) & weak;
+ safeThreats = (shift<Right>(b) | shift<Left>(b)) & weak;
if (weak ^ safeThreats)
score += ThreatByHangingPawn;
{
b = (defended | weak) & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
while (b)
- score += Threat[Minor][type_of(pos.piece_on(pop_lsb(&b)))];
+ {
+ Square s = pop_lsb(&b);
+ score += Threat[Minor][type_of(pos.piece_on(s))];
+ if (type_of(pos.piece_on(s)) != PAWN)
+ score += ThreatByRank * (int)relative_rank(Them, s);
+ }
b = (pos.pieces(Them, QUEEN) | weak) & ei.attackedBy[Us][ROOK];
while (b)
- score += Threat[Rook ][type_of(pos.piece_on(pop_lsb(&b)))];
+ {
+ Square s = pop_lsb(&b);
+ score += Threat[Rook][type_of(pos.piece_on(s))];
+ if (type_of(pos.piece_on(s)) != PAWN)
+ score += ThreatByRank * (int)relative_rank(Them, s);
+ }
score += Hanging * popcount(weak & ~ei.attackedBy[Them][ALL_PIECES]);
// Bonus if some pawns can safely push and attack an enemy piece
b = pos.pieces(Us, PAWN) & ~TRank7BB;
- b = shift_bb<Up>(b | (shift_bb<Up>(b & TRank2BB) & ~pos.pieces()));
+ b = shift<Up>(b | (shift<Up>(b & TRank2BB) & ~pos.pieces()));
b &= ~pos.pieces()
& ~ei.attackedBy[Them][PAWN]
& (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]);
- b = (shift_bb<Left>(b) | shift_bb<Right>(b))
+ b = (shift<Left>(b) | shift<Right>(b))
& pos.pieces(Them)
& ~ei.attackedBy[Us][PAWN];
score += ThreatByPawnPush * popcount(b);
- // King tropism: firstly, find squares that we attack in the enemy king flank
- b = ei.attackedBy[Us][ALL_PIECES] & KingFlank[Them][file_of(pos.square<KING>(Them))];
-
- // Secondly, add to the bitboard the squares which we attack twice in that flank
- // but which are not protected by a enemy pawn. Note the trick to shift away the
- // previous attack bits to the empty part of the bitboard.
- b = (b & ei.attackedBy2[Us] & ~ei.attackedBy[Them][PAWN])
- | (Us == WHITE ? b >> 4 : b << 4);
-
- // Count all these squares with a single popcount
- score += make_score(7 * popcount(b), 0);
-
if (DoTrace)
Trace::add(THREAT, Us, score);
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Bitboard b, squaresToQueen, defendedSquares, unsafeSquares;
+ Bitboard b, bb, squaresToQueen, defendedSquares, unsafeSquares;
Score score = SCORE_ZERO;
b = ei.pi->passed_pawns(Us);
assert(pos.pawn_passed(Us, s));
assert(!(pos.pieces(PAWN) & forward_bb(Us, s)));
+ bb = forward_bb(Us, s) & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
+ score -= HinderPassedPawn * popcount(bb);
+
int r = relative_rank(Us, s) - RANK_2;
int rr = r * (r - 1);
// in the pawn's path attacked or occupied by the enemy.
defendedSquares = unsafeSquares = squaresToQueen = forward_bb(Us, s);
- Bitboard bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from<ROOK>(s);
+ bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from<ROOK>(s);
if (!(pos.pieces(Us) & bb))
defendedSquares &= ei.attackedBy[Us][ALL_PIECES];
// ...count safe + (behind & safe) with a single popcount
int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
bonus = std::min(16, bonus);
- int weight = pos.count<ALL_PIECES>(Us);
+ int weight = pos.count<ALL_PIECES>(Us) - 2 * ei.pi->open_files();
- return make_score(bonus * weight * weight / 22, 0);
+ return make_score(bonus * weight * weight / 18, 0);
}
assert(!pos.checkers());
+ Score mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO };
EvalInfo ei;
- Score score, mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO };
-
- // Initialize score by reading the incrementally updated scores included in
- // the position object (material + piece square tables). Score is computed
- // internally from the white point of view.
- score = pos.psq_score();
// Probe the material hash table
ei.me = Material::probe(pos);
- score += ei.me->imbalance();
// If we have a specialized evaluation function for the current material
// configuration, call it and return.
if (ei.me->specialized_eval_exists())
return ei.me->evaluate(pos);
+ // Initialize score by reading the incrementally updated scores included in
+ // the position object (material + piece square tables) and the material
+ // imbalance. Score is computed internally from the white point of view.
+ Score score = pos.psq_score() + ei.me->imbalance();
+
// Probe the pawn hash table
ei.pi = Pawns::probe(pos);
score += ei.pi->pawns_score();
// Pawns blocked or on ranks 2 and 3 will be excluded from the mobility area
Bitboard blockedPawns[] = {
- pos.pieces(WHITE, PAWN) & (shift_bb<DELTA_S>(pos.pieces()) | Rank2BB | Rank3BB),
- pos.pieces(BLACK, PAWN) & (shift_bb<DELTA_N>(pos.pieces()) | Rank7BB | Rank6BB)
+ pos.pieces(WHITE, PAWN) & (shift<SOUTH>(pos.pieces()) | Rank2BB | Rank3BB),
+ pos.pieces(BLACK, PAWN) & (shift<NORTH>(pos.pieces()) | Rank7BB | Rank6BB)
};
// Do not include in mobility area squares protected by enemy pawns, or occupied
return ss.str();
}
-
-
-/// init() computes evaluation weights, usually at startup
-
-void Eval::init() {
-
- const int MaxSlope = 322;
- const int Peak = 47410;
- int t = 0;
-
- for (int i = 0; i < 400; ++i)
- {
- t = std::min(Peak, std::min(i * i - 16, t + MaxSlope));
- KingDanger[i] = make_score(t * 268 / 7700, 0);
- }
-}
projects / stockfish / blobdiff