((1ULL << SQ_A8) | (1ULL << SQ_H8))
};
- // The SpaceMask[color] contains the area of the board which is consdered
+ // 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
// based on how many squares inside this area are safe and available for
// friendly minor pieces.
// 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);
void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo& ei);
void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, 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[]);
+ inline Score apply_weight(Score v, int wmg, int weg);
+ Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]);
int weight_option(const std::string& opt, int weight);
void init_safety();
}
assert(pos.is_ok());
assert(threadID >= 0 && threadID < THREAD_MAX);
+ assert(!pos.is_check());
memset(&ei, 0, sizeof(EvalInfo));
// Initialize by reading the incrementally updated scores included in the
// position object (material + piece square tables)
- ei.mgValue = pos.mg_value();
- ei.egValue = pos.eg_value();
+ ei.value = pos.value();
// Probe the material hash table
ei.mi = MaterialTable[threadID]->get_material_info(pos);
- ei.mgValue += ei.mi->material_value();
- ei.egValue += ei.mi->material_value();
+ ei.value += ei.mi->material_value();
// If we have a specialized evaluation function for the current material
// configuration, call it and return
// Probe the pawn hash table
ei.pi = PawnTable[threadID]->get_pawn_info(pos);
- ei.mgValue += apply_weight(ei.pi->mg_value(), WeightPawnStructureMidgame);
- ei.egValue += apply_weight(ei.pi->eg_value(), WeightPawnStructureEndgame);
+ ei.value += apply_weight(ei.pi->value(), WeightPawnStructureMidgame, WeightPawnStructureEndgame);
// Initialize king attack bitboards and king attack zones for both sides
ei.attackedBy[WHITE][KING] = pos.attacks_from<KING>(pos.king_square(WHITE));
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);
if ( square_file(pos.king_square(WHITE)) >= FILE_E
&& square_file(pos.king_square(BLACK)) <= FILE_D)
- ei.mgValue += ei.pi->queenside_storm_value(WHITE)
- - ei.pi->kingside_storm_value(BLACK);
+ ei.value += Score(ei.pi->queenside_storm_value(WHITE) - ei.pi->kingside_storm_value(BLACK), 0);
else if ( square_file(pos.king_square(WHITE)) <= FILE_D
&& square_file(pos.king_square(BLACK)) >= FILE_E)
- ei.mgValue += ei.pi->kingside_storm_value(WHITE)
- - ei.pi->queenside_storm_value(BLACK);
+ ei.value += Score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0);
// Evaluate space for both sides
if (ei.mi->space_weight() > 0)
}
// Mobility
- ei.mgValue += apply_weight(ei.mgMobility, WeightMobilityMidgame);
- ei.egValue += apply_weight(ei.egMobility, WeightMobilityEndgame);
+ ei.value += apply_weight(Score(ei.mgMobility, ei.egMobility), WeightMobilityMidgame, WeightMobilityEndgame);
// If we don't already have an unusual scale factor, check for opposite
// 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))
- || (factor[BLACK] == SCALE_FACTOR_NORMAL && ei.egValue < Value(0))))
+ && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && ei.value.eg() > Value(0))
+ || (factor[BLACK] == SCALE_FACTOR_NORMAL && ei.value.eg() < Value(0))))
{
ScaleFactor sf;
// Interpolate between the middle game and the endgame score
Color stm = pos.side_to_move();
- Value v = Sign[stm] * scale_by_game_phase(ei.mgValue, ei.egValue, phase, factor);
+ Value v = Sign[stm] * scale_by_game_phase(ei.value, phase, factor);
return (ei.mateThreat[stm] == MOVE_NONE ? v : 8 * QueenValueMidgame - v);
}
static const
ScaleFactor sf[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL};
- Value mgv = pos.mg_value();
- Value egv = pos.eg_value();
Phase ph = pos.game_phase();
Color stm = pos.side_to_move();
- return Sign[stm] * scale_by_game_phase(mgv, egv, ph, sf);
+ return Sign[stm] * scale_by_game_phase(pos.value(), ph, sf);
}
// evaluate_mobility() computes mobility and attacks for every piece
template<PieceType Piece, Color Us, bool HasPopCnt>
- int evaluate_mobility(const Position& pos, const Bitboard& mob_bb, 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* EgBonus[] = { 0, 0, EndgameKnightMobilityBonus, EndgameBishopMobilityBonus, EndgameRookMobilityBonus, EndgameQueenMobilityBonus };
// Update attack info
- ei.attackedBy[Us][Piece] |= mob_bb;
+ ei.attackedBy[Us][Piece] |= b;
// King attacks
- if (mob_bb & ei.kingZone[Us])
+ if (b & ei.kingZone[Us])
{
ei.kingAttackersCount[Us]++;
ei.kingAttackersWeight[Us] += AttackWeight[Piece];
- Bitboard b = (mob_bb & ei.attackedBy[Them][KING]);
- if (b)
- ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15<HasPopCnt>(b);
+ Bitboard bb = (b & ei.attackedBy[Them][KING]);
+ if (bb)
+ ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15<HasPopCnt>(bb);
}
- // Remove squares protected by enemy pawns or occupied by our pieces
- Bitboard b = mob_bb & ~ei.attackedBy[Them][PAWN] & ~pos.pieces_of_color(Us);
-
// Mobility
- int mob = (Piece != QUEEN ? count_1s_max_15<HasPopCnt>(b) : count_1s<HasPopCnt>(b));
+ 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];
else
bonus += bonus / 2;
}
- ei.mgValue += Sign[Us] * bonus;
- ei.egValue += Sign[Us] * bonus;
+ ei.value += Sign[Us] * Score(bonus, bonus);
}
template<PieceType Piece, Color Us, bool HasPopCnt>
void evaluate_pieces(const Position& pos, EvalInfo& ei) {
- Bitboard mob_bb;
+ Bitboard b;
Square s, ksq;
int mob;
File f;
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)
-
mob_bb = pos.attacks_from<Piece>(s);
+ b = pos.attacks_from<Piece>(s);
else if (Piece == BISHOP)
- mob_bb = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us));
+ b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us));
else if (Piece == ROOK)
- mob_bb = rook_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us));
+ b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us));
else
assert(false);
// Attacks and mobility
- mob = evaluate_mobility<Piece, Us, HasPopCnt>(pos, mob_bb, 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.value -= Sign[Us] * Score(MidgameThreatedByPawnPenalty[Piece], EndgameThreatedByPawnPenalty[Piece]);
// Bishop and knight outposts squares
if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Them))
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);
+ ei.value += Sign[Us] * (Piece == ROOK ? Score(MidgameRookOn7thBonus, EndgameRookOn7thBonus)
+ : Score(MidgameQueenOn7thBonus, EndgameQueenOn7thBonus));
}
}
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;
- }
+ ei.value += Sign[Us] * Score(RookOpenFileBonus, RookOpenFileBonus);
else
- {
- ei.mgValue += Sign[Us] * RookHalfOpenFileBonus;
- ei.egValue += Sign[Us] * RookHalfOpenFileBonus;
- }
+ ei.value += Sign[Us] * Score(RookHalfOpenFileBonus, RookHalfOpenFileBonus);
}
// Penalize rooks which are trapped inside a king. Penalize more if
{
// 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);
+ ei.value -= Sign[Us] * Score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
+ : (TrappedRookPenalty - mob * 16), 0);
}
else if ( square_file(ksq) <= FILE_D
&& square_file(s) < square_file(ksq)
{
// 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);
+ ei.value -= Sign[Us] * Score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
+ : (TrappedRookPenalty - mob * 16), 0);
}
}
}
}
+ // 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;
+ Score bonus(0, 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))
+ bonus += Score(MidgameThreatBonus[pt1][pt2], EndgameThreatBonus[pt1][pt2]);
+ }
+ ei.value += Sign[Us] * bonus;
+ }
+
+
// evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
// pieces of a given color.
if (relative_rank(Us, s) <= RANK_4)
{
shelter = ei.pi->get_king_shelter(pos, Us, s);
- ei.mgValue += Sign[Us] * Value(shelter);
+ ei.value += Sign[Us] * Score(shelter, 0);
}
// King safety. This is quite complicated, and is almost certainly far
// change far bigger than the value of the captured piece.
Value v = apply_weight(SafetyTable[attackUnits], WeightKingSafety[Us]);
- ei.mgValue -= Sign[Us] * v;
+ ei.value -= Sign[Us] * Score(v, 0);
if (Us == pos.side_to_move())
ei.futilityMargin += v;
}
- // evaluate_passed_pawns() evaluates the passed pawns for both sides
+ // evaluate_passed_pawns() evaluates the passed pawns of the given color
- void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
+ template<Color Us>
+ void evaluate_passed_pawns_of_color(const Position& pos, int movesToGo[], Square pawnToGo[], EvalInfo& ei) {
- bool hasUnstoppable[2] = {false, false};
- int movesToGo[2] = {100, 100};
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
- for (Color us = WHITE; us <= BLACK; us++)
+ Bitboard b2, b3, b4;
+ Square ourKingSq = pos.king_square(Us);
+ Square theirKingSq = pos.king_square(Them);
+ Bitboard b = ei.pi->passed_pawns() & pos.pieces(PAWN, Us);
+
+ while (b)
{
- Color them = opposite_color(us);
- Square ourKingSq = pos.king_square(us);
- Square theirKingSq = pos.king_square(them);
- Bitboard b = ei.pi->passed_pawns() & pos.pieces(PAWN, us), b2, b3, b4;
+ Square s = pop_1st_bit(&b);
- 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));
- 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));
- 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);
- // 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)
+ {
+ 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);
- // Adjust bonus based on king proximity
- if (tr != 0)
+ // If the pawn is free to advance, increase bonus
+ if (pos.square_is_empty(blockSq))
{
- 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);
+ // There are no enemy pawns in the pawn's path
+ b2 = squares_in_front_of(Us, s);
- // 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.pieces(ROOK, QUEEN, them)))
- 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!
- 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?
- // 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));
-
- // 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);
- }
- }
+ assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB);
- // If the pawn is supported by a friendly pawn, increase bonus
- b2 = pos.pieces(PAWN, us) & neighboring_files_bb(s);
- if (b2 & rank_bb(s))
- ebonus += Value(r * 20);
- else if (pos.attacks_from<PAWN>(s, them) & b2)
- ebonus += Value(r * 12);
+ // Squares attacked by us
+ b4 = b2 & ei.attacked_by(Us);
- // 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;
+ // Squares attacked or occupied by enemy pieces
+ b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them));
- 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 there is an enemy rook or queen attacking the pawn from behind,
+ // add all X-ray attacks by the rook or queen.
+ 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;
- 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);
- }
- }
+ // 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 ?
+ // 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));
+
+ // 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)
+ } // tr != 0
+
+ // If the pawn is supported by a friendly pawn, increase bonus
+ b2 = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
+ if (b2 & rank_bb(s))
+ ebonus += Value(r * 20);
+ else if (pos.attacks_from<PAWN>(s, Them) & 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)
{
- if ( pos.non_pawn_material(them) <= KnightValueMidgame
- && pos.piece_count(them, KNIGHT) <= 1)
- ebonus += ebonus / 4;
- else if (pos.pieces(ROOK, QUEEN, them))
- ebonus -= ebonus / 4;
+ 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 && (!movesToGo[Us] || movesToGo[Us] > mtg))
+ {
+ movesToGo[Us] = mtg;
+ pawnToGo[Us] = s;
+ }
}
+ }
- // 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);
+ // 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.pieces(ROOK, QUEEN, Them))
+ ebonus -= ebonus / 4;
}
- }
- // 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])
+ // Add the scores for this pawn to the middle game and endgame eval.
+ ei.value += Score(apply_weight(Sign[Us] * mbonus, WeightPassedPawnsMidgame),
+ apply_weight(Sign[Us] * ebonus, WeightPassedPawnsEndgame));
+
+ } // while
+ }
+
+
+ // evaluate_passed_pawns() evaluates the passed pawns for both sides
+
+ void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
+
+ int movesToGo[2] = {0, 0};
+ Square pawnToGo[2] = {SQ_NONE, SQ_NONE};
+
+ // Evaluate pawns for each color
+ 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.value += Score(0, 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.value += Score(0, 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.value += Score(0, Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2))));
+ }
}
}
&& pos.see(s, b6) < 0
&& pos.see(s, b8) < 0)
{
- ei.mgValue -= Sign[us] * TrappedBishopA7H7Penalty;
- ei.egValue -= Sign[us] * TrappedBishopA7H7Penalty;
+ ei.value -= Sign[us] * Score(TrappedBishopA7H7Penalty, TrappedBishopA7H7Penalty);
}
}
else
penalty = TrappedBishopA1H1Penalty / 2;
- ei.mgValue -= Sign[us] * penalty;
- ei.egValue -= Sign[us] * penalty;
+ ei.value -= Sign[us] * Score(penalty, penalty);
}
}
int space = count_1s_max_15<HasPopCnt>(safeSquares)
+ count_1s_max_15<HasPopCnt>(behindFriendlyPawns & safeSquares);
- ei.mgValue += Sign[Us] * apply_weight(Value(space * ei.mi->space_weight()), WeightSpace);
+ ei.value += Sign[Us] * Score(apply_weight(Value(space * ei.mi->space_weight()), WeightSpace), 0);
}
return (v*w) / 0x100;
}
+ inline Score apply_weight(Score v, int wmg, int weg) {
+ return Score(v.mg()*wmg, v.eg()*weg) / 0x100;
+ }
+
// 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.
- Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]) {
+ Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]) {
- assert(mv > -VALUE_INFINITE && mv < VALUE_INFINITE);
- assert(ev > -VALUE_INFINITE && ev < VALUE_INFINITE);
+ assert(v.mg() > -VALUE_INFINITE && v.mg() < VALUE_INFINITE);
+ assert(v.eg() > -VALUE_INFINITE && v.eg() < VALUE_INFINITE);
assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
- ev = apply_scale_factor(ev, sf[(ev > Value(0) ? WHITE : BLACK)]);
+ Value ev = apply_scale_factor(v.eg(), sf[(v.eg() > Value(0) ? WHITE : BLACK)]);
- Value result = Value(int((mv * ph + ev * (128 - ph)) / 128));
+ Value result = Value(int((v.mg() * ph + ev * (128 - ph)) / 128));
return Value(int(result) & ~(GrainSize - 1));
}
}
}
}
+
+std::ostream& operator<<(std::ostream &os, Score s) {
+
+ return os << "(" << s.mg() << ", " << s.eg() << ")";
+}
projects / stockfish / blobdiff