// Bonus for having a mate threat, initialized from UCI options
int MateThreatBonus;
+ // ThreatBonus[][] contains bonus according to which piece type
+ // attacks which one.
+ const Value MidgameThreatBonus[8][8] = {
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0),V(18), V(0),V(37), V(55), V(55), V(0), V(0) }, // KNIGHT attacks
+ { V(0),V(18),V(37), V(0), V(55), V(55), V(0), V(0) }, // BISHOP attacks
+ { V(0), V(9),V(27),V(27), V(0), V(37), V(0), V(0) }, // ROOK attacks
+ { V(0),V(27),V(27),V(27), V(27), V(0), V(0), V(0) }, // QUEEN attacks
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) } // not used
+ };
+
+ const Value EndgameThreatBonus[8][8] = {
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0),V(37), V(0),V(47), V(97), V(97), V(0), V(0) }, // KNIGHT attacks
+ { V(0),V(37),V(47), V(0), V(97), V(97), V(0), V(0) }, // BISHOP attacks
+ { V(0),V(27),V(47),V(47), V(0), V(47), V(0), V(0) }, // ROOK attacks
+ { V(0),V(37),V(37),V(37), V(37), V(0), V(0), V(0) }, // QUEEN attacks
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) } // not used
+ };
+
+ // ThreatedByPawnPenalty[] contains a penalty according to which piece
+ // type is attacked by an enemy pawn.
+ const Value MidgameThreatedByPawnPenalty[8] = {
+ V(0), V(0), V(56), V(56), V(76), V(86), V(0), V(0)
+ };
+
+ const Value EndgameThreatedByPawnPenalty[8] = {
+ V(0), V(0), V(70), V(70), V(99), V(118), V(0), V(0)
+ };
+
// InitKingDanger[] contains bonuses based on the position of the defending
// king.
const int InitKingDanger[64] = {
template<Color Us, bool HasPopCnt>
void evaluate_king(const Position& pos, EvalInfo& ei);
+ template<Color Us>
+ void evaluate_threats(const Position& pos, EvalInfo& ei);
+
template<Color Us, bool HasPopCnt>
void evaluate_space(const Position& pos, EvalInfo& ei);
assert(pos.is_ok());
assert(threadID >= 0 && threadID < THREAD_MAX);
+ assert(!pos.is_check());
memset(&ei, 0, sizeof(EvalInfo));
evaluate_king<WHITE, HasPopCnt>(pos, ei);
evaluate_king<BLACK, HasPopCnt>(pos, ei);
+ // Evaluate tactical threats, we need full attack info
+ evaluate_threats<WHITE>(pos, ei);
+ evaluate_threats<BLACK>(pos, 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
- // both sides have an unstoppable passed pawn.
+ // both sides have an unstoppable passed pawn. To be called after all attacks
+ // are computed, included king.
if (ei.pi->passed_pawns())
evaluate_passed_pawns(pos, ei);
// evaluate_mobility() computes mobility and attacks for every piece
template<PieceType Piece, Color Us, bool HasPopCnt>
- int evaluate_mobility(const Position& pos, Bitboard b, EvalInfo& ei) {
+ int evaluate_mobility(Bitboard b, Bitboard mob_area, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
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 int lastIndex[] = { 0, 0, 8, 15, 15, 31 };
// Update attack info
ei.attackedBy[Us][Piece] |= b;
ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15<HasPopCnt>(bb);
}
- // Remove squares protected by enemy pawns or occupied by our pieces
- b &= ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
-
- // The squares occupied by enemy pieces (not defended by pawns) will be
- // counted two times instead of one. The shift (almost) guarantees that
- // intersection of the shifted value with b is zero so that after or-ing
- // the count of 1s bits is increased by the number of affected squares.
- b |= Us == WHITE ? ((b & pos.pieces_of_color(Them)) >> 1)
- : ((b & pos.pieces_of_color(Them)) << 1);
-
// Mobility
- int mob = (Piece != QUEEN ? count_1s_max_15<HasPopCnt>(b)
- : count_1s<HasPopCnt>(b));
-
- if (mob > lastIndex[Piece])
- mob = lastIndex[Piece];
+ int mob = (Piece != QUEEN ? count_1s_max_15<HasPopCnt>(b & mob_area)
+ : count_1s<HasPopCnt>(b & mob_area));
ei.mgMobility += Sign[Us] * MgBonus[Piece][mob];
ei.egMobility += Sign[Us] * EgBonus[Piece][mob];
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Square* ptr = pos.piece_list_begin(Us, Piece);
+ // Do not include in mobility squares protected by enemy pawns or occupied by our pieces
+ const Bitboard mob_area = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
+
while ((s = *ptr++) != SQ_NONE)
{
if (Piece == KNIGHT || Piece == QUEEN)
assert(false);
// Attacks and mobility
- mob = evaluate_mobility<Piece, Us, HasPopCnt>(pos, b, ei);
+ mob = evaluate_mobility<Piece, Us, HasPopCnt>(b, mob_area, ei);
+
+ // 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 (bit_is_set(ei.attackedBy[Them][PAWN], s))
+ {
+ ei.mgValue -= Sign[Us] * MidgameThreatedByPawnPenalty[Piece];
+ ei.egValue -= Sign[Us] * EndgameThreatedByPawnPenalty[Piece];
+ }
// Bishop and knight outposts squares
if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Them))
}
+ // evaluate_threats<>() assigns bonuses according to the type of attacking piece
+ // and the type of attacked one.
+
+ template<Color Us>
+ void evaluate_threats(const Position& pos, EvalInfo& ei) {
+
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+ Bitboard b;
+ Value mgBonus = Value(0);
+ Value egBonus = Value(0);
+
+ // Enemy pieces not defended by a pawn and under our attack
+ Bitboard weakEnemies = pos.pieces_of_color(Them)
+ & ~ei.attackedBy[Them][PAWN]
+ & ei.attackedBy[Us][0];
+ if (!weakEnemies)
+ return;
+
+ // Add bonus according to type of attacked enemy pieces and to the
+ // type of attacking piece, from knights to queens. Kings are not
+ // considered because are already special handled in king evaluation.
+ for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
+ {
+ b = ei.attackedBy[Us][pt1] & weakEnemies;
+ if (b)
+ for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
+ if (b & pos.pieces(pt2))
+ {
+ mgBonus += MidgameThreatBonus[pt1][pt2];
+ egBonus += EndgameThreatBonus[pt1][pt2];
+ }
+ }
+ ei.mgValue += Sign[Us] * mgBonus;
+ ei.egValue += Sign[Us] * egBonus;
+ }
+
+
// evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
// pieces of a given color.
// evaluate_passed_pawns() evaluates the passed pawns of the given color
template<Color Us>
- void evaluate_passed_pawns_of_color(const Position& pos, bool hasUnstoppable[], int movesToGo[], EvalInfo& ei) {
+ void evaluate_passed_pawns_of_color(const Position& pos, int movesToGo[], Square pawnToGo[], EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
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)
+ if (tr)
{
+ Square blockSq = s + pawn_push(Us);
+
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))
{
+ // There are no enemy pawns in the pawn's path
b2 = squares_in_front_of(Us, s);
- b3 = b2 & ei.attacked_by(Them);
+
+ assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB);
+
+ // Squares attacked by us
b4 = b2 & ei.attacked_by(Us);
+ // Squares attacked or occupied by enemy pieces
+ b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them));
+
// 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.pieces(ROOK, QUEEN, Them)))
+ if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them))
+ && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<QUEEN>(s)))
b3 = b2;
- // Squares attacked or occupied by enemy pieces
- b3 |= (b2 & pos.pieces_of_color(Them));
-
- // There are no enemy pawns in the pawn's path
- assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB);
-
// Are any of the squares in the pawn's path attacked or occupied by the enemy?
if (b3 == EmptyBoardBB)
// No enemy attacks or pieces, huge bonus!
+ // Even bigger if we protect the pawn's path
ebonus += Value(tr * (b2 == b4 ? 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?
+ // 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));
int blockerCount = count_1s_max_15(squares_in_front_of(Us,s) & pos.occupied_squares());
mtg += blockerCount;
d += blockerCount;
- if (d < 0)
+ if (d < 0 && (!movesToGo[Us] || movesToGo[Us] > mtg))
{
- hasUnstoppable[Us] = true;
- movesToGo[Us] = Min(movesToGo[Us], mtg);
+ movesToGo[Us] = mtg;
+ pawnToGo[Us] = s;
}
}
}
void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
- bool hasUnstoppable[2] = {false, false};
- int movesToGo[2] = {100, 100};
+ int movesToGo[2] = {0, 0};
+ Square pawnToGo[2] = {SQ_NONE, SQ_NONE};
// Evaluate pawns for each color
- evaluate_passed_pawns_of_color<WHITE>(pos, hasUnstoppable, movesToGo, ei);
- evaluate_passed_pawns_of_color<BLACK>(pos, hasUnstoppable, movesToGo, ei);
-
- // 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])
+ evaluate_passed_pawns_of_color<WHITE>(pos, movesToGo, pawnToGo, ei);
+ evaluate_passed_pawns_of_color<BLACK>(pos, movesToGo, pawnToGo, ei);
+
+ // Neither side has an unstoppable passed pawn?
+ if (!(movesToGo[WHITE] | movesToGo[BLACK]))
+ return;
+
+ // Does only one side have an unstoppable passed pawn?
+ if (!movesToGo[WHITE] || !movesToGo[BLACK])
{
- // Both sides have unstoppable pawns! Try to find out who queens
+ Color winnerSide = movesToGo[WHITE] ? WHITE : BLACK;
+ ei.egValue += Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * movesToGo[winnerSide]));
+ }
+ else
+ { // 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.
+ Color winnerSide = movesToGo[WHITE] < movesToGo[BLACK] ? WHITE : BLACK;
+ Color loserSide = opposite_color(winnerSide);
+
+ // If one side queens at least three plies before the other, that side wins
+ if (movesToGo[winnerSide] <= movesToGo[loserSide] - 3)
+ ei.egValue += Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2)));
+
+ // If one side queens one ply before the other and checks the king or attacks
+ // the undefended opponent's queening square, that side wins. To avoid cases
+ // where the opponent's king could move somewhere before first pawn queens we
+ // consider only free paths to queen for both pawns.
+ else if ( !(squares_in_front_of(WHITE, pawnToGo[WHITE]) & pos.occupied_squares())
+ && !(squares_in_front_of(BLACK, pawnToGo[BLACK]) & pos.occupied_squares()))
+ {
+ assert(movesToGo[loserSide] - movesToGo[winnerSide] == 1);
+
+ Square winnerQSq = relative_square(winnerSide, make_square(square_file(pawnToGo[winnerSide]), RANK_8));
+ Square loserQSq = relative_square(loserSide, make_square(square_file(pawnToGo[loserSide]), RANK_8));
+
+ Bitboard b = pos.occupied_squares();
+ clear_bit(&b, pawnToGo[winnerSide]);
+ clear_bit(&b, pawnToGo[loserSide]);
+ b = queen_attacks_bb(winnerQSq, b);
+
+ if ( (b & pos.pieces(KING, loserSide))
+ ||(bit_is_set(b, loserQSq) && !bit_is_set(ei.attacked_by(loserSide), loserQSq)))
+ ei.egValue += Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2)));
+ }
}
}
Square b8 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B8 : SQ_G8);
if ( pos.piece_on(b6) == piece_of_color_and_type(opposite_color(us), PAWN)
- && pos.see(s, b6) < 0
- && pos.see(s, b8) < 0)
+ && pos.see(s, b6, false) < 0
+ && pos.see(s, b8, false) < 0)
{
ei.mgValue -= Sign[us] * TrappedBishopA7H7Penalty;
ei.egValue -= Sign[us] * TrappedBishopA7H7Penalty;
projects / stockfish / blobdiff