enum { PawnStructure, PassedPawns, Space, KingSafety };
const struct Weight { int mg, eg; } Weights[] = {
- {214, 203}, {193, 262}, {47, 0}, {330, 0}
- };
+ {214, 203}, {193, 262}, {47, 0}, {330, 0} };
Score operator*(Score s, const Weight& w) {
return make_score(mg_value(s) * w.mg / 256, eg_value(s) * w.eg / 256);
{ S( 8, 2), S(13, 4) } // Bishops
};
- // Threat[minor/rook][attacked PieceType] contains
+ // RookOnFile[semiopen/open] contains bonuses for each rook when there is no
+ // friendly pawn on the rook file.
+ const Score RookOnFile[2] = { S(19, 10), S(43, 21) };
+
+ // ThreatBySafePawn[PieceType] contains bonuses according to which piece
+ // type is attacked by a pawn which is protected or 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) };
+
+ // Threat[by minor/by rook][attacked PieceType] contains
// bonuses according to which piece type attacks which one.
// Attacks on lesser pieces which are pawn defended are not considered.
- const Score Threat[2][PIECE_TYPE_NB] = {
- { S(0, 0), S(0, 33), S(45, 43), S(46, 47), S(72, 107), S(48,118) }, // Minor attacks
- { S(0, 0), S(0, 25), S(40, 62), S(40, 59), S( 0, 34), S(35, 48) } // Rook attacks
+ const Score Threat[][PIECE_TYPE_NB] = {
+ { S(0, 0), S(0, 33), S(45, 43), S(46, 47), S(72,107), S(48,118) }, // by Minor
+ { S(0, 0), S(0, 25), S(40, 62), S(40, 59), S( 0, 34), S(35, 48) } // by Rook
};
- // ThreatenedByPawn[PieceType] contains a penalty according to which piece
- // type is attacked by a pawn.
- const Score ThreatenedByPawn[PIECE_TYPE_NB] = {
- S(0, 0), S(0, 0), S(176, 139), S(131, 127), S(217, 218), S(203, 215)
- };
+ // ThreatByKing[on one/on many] contains bonuses for King attacks on
+ // pawns or pieces which are not pawn defended.
+ const Score ThreatByKing[2] = { S(3, 62), S(9, 138) };
// Passed[mg/eg][Rank] contains midgame and endgame bonuses for passed pawns.
// We don't use a Score because we process the two components independently.
{ V(7), V(14), V(37), V(63), V(134), V(189) }
};
- // PassedFile[File] contains a bonus according to the file of a passed pawn.
- const Score PassedFile[] = {
- S( 12, 10), S( 3, 10), S( 1, -8), S(-27, -12),
- S(-27, -12), S( 1, -8), S( 3, 10), S( 12, 10)
+ // PassedFile[File] contains a bonus according to the file of a passed pawn
+ const Score PassedFile[FILE_NB] = {
+ S( 12, 10), S( 3, 10), S( 1, -8), S(-27,-12),
+ S(-27,-12), S( 1, -8), S( 3, 10), S( 12, 10)
};
- const Score ThreatenedByHangingPawn = S(70, 63);
-
// Assorted bonuses and penalties used by evaluation
- const Score KingOnOne = S( 3, 62);
- const Score KingOnMany = S( 9,138);
- const Score RookOnPawn = S( 7, 27);
- const Score RookOnOpenFile = S(43, 21);
- const Score RookOnSemiOpenFile = S(19, 10);
- const Score BishopPawns = S( 8, 12);
- const Score MinorBehindPawn = S(16, 0);
- const Score TrappedRook = S(92, 0);
- const Score Unstoppable = S( 0, 20);
- const Score Hanging = S(48, 28);
- const Score PawnAttackThreat = S(31, 19);
- const Score Checked = S(20, 20);
+ const Score MinorBehindPawn = S(16, 0);
+ const Score BishopPawns = S( 8, 12);
+ const Score RookOnPawn = S( 7, 27);
+ const Score TrappedRook = S(92, 0);
+ const Score Checked = S(20, 20);
+ const Score ThreatByHangingPawn = S(70, 63);
+ const Score Hanging = S(48, 28);
+ const Score ThreatByPawnPush = S(31, 19);
+ const Score Unstoppable = S( 0, 20);
// 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
{
Bitboard alignedPawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s];
if (alignedPawns)
- score += popcount<Max15>(alignedPawns) * RookOnPawn;
+ score += RookOnPawn * popcount<Max15>(alignedPawns);
}
// Bonus when on an open or semi-open file
if (ei.pi->semiopen_file(Us, file_of(s)))
- score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOnOpenFile : RookOnSemiOpenFile;
+ score += RookOnFile[!!ei.pi->semiopen_file(Them, file_of(s))];
// Penalize when trapped by the king, even more if king cannot castle
- if (mob <= 3 && !ei.pi->semiopen_file(Us, file_of(s)))
+ else if (mob <= 3)
{
Square ksq = pos.square<KING>(Us);
safeThreats = (shift_bb<Right>(b) | shift_bb<Left>(b)) & weak;
if (weak ^ safeThreats)
- score += ThreatenedByHangingPawn;
+ score += ThreatByHangingPawn;
while (safeThreats)
- score += ThreatenedByPawn[type_of(pos.piece_on(pop_lsb(&safeThreats)))];
+ score += ThreatBySafePawn[type_of(pos.piece_on(pop_lsb(&safeThreats)))];
}
// Non-pawn enemies defended by a pawn
b = weak & ei.attackedBy[Us][KING];
if (b)
- score += more_than_one(b) ? KingOnMany : KingOnOne;
+ score += ThreatByKing[more_than_one(b)];
}
// Bonus if some pawns can safely push and attack an enemy piece
& ~ei.attackedBy[Us][PAWN];
if (b)
- score += popcount<Max15>(b) * PawnAttackThreat;
+ score += ThreatByPawnPush * popcount<Max15>(b);
if (DoTrace)
Trace::add(THREAT, Us, score);
{
Bitboard b;
if ((b = ei.pi->passed_pawns(WHITE)) != 0)
- score += int(relative_rank(WHITE, frontmost_sq(WHITE, b))) * Unstoppable;
+ score += Unstoppable * int(relative_rank(WHITE, frontmost_sq(WHITE, b)));
if ((b = ei.pi->passed_pawns(BLACK)) != 0)
- score -= int(relative_rank(BLACK, frontmost_sq(BLACK, b))) * Unstoppable;
+ score -= Unstoppable * int(relative_rank(BLACK, frontmost_sq(BLACK, b)));
}
// Evaluate space for both sides, only during opening
{
Trace::add(MATERIAL, pos.psq_score());
Trace::add(IMBALANCE, ei.me->imbalance());
- Trace::add(PAWN, ei.pi->pawns_score());
+ Trace::add(PAWN, ei.pi->pawns_score() * Weights[PawnStructure]);
Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]);
Trace::add(SPACE, evaluate_space<WHITE>(pos, ei) * Weights[Space]
, evaluate_space<BLACK>(pos, ei) * Weights[Space]);
#define V Value
#define S(mg, eg) make_score(mg, eg)
- // Doubled pawn penalty by file
- const Score Doubled[FILE_NB] = {
- S(13, 43), S(20, 48), S(23, 48), S(23, 48),
- S(23, 48), S(23, 48), S(20, 48), S(13, 43) };
-
// Isolated pawn penalty by opposed flag and file
const Score Isolated[2][FILE_NB] = {
- { S(37, 45), S(54, 52), S(60, 52), S(60, 52),
- S(60, 52), S(60, 52), S(54, 52), S(37, 45) },
- { S(25, 30), S(36, 35), S(40, 35), S(40, 35),
- S(40, 35), S(40, 35), S(36, 35), S(25, 30) } };
+ { S(37, 45), S(54, 52), S(60, 52), S(60, 52),
+ S(60, 52), S(60, 52), S(54, 52), S(37, 45) },
+ { S(25, 30), S(36, 35), S(40, 35), S(40, 35),
+ S(40, 35), S(40, 35), S(36, 35), S(25, 30) } };
// Backward pawn penalty by opposed flag
const Score Backward[2] = { S(67, 42), S(49, 24) };
+
+ // Unsupported pawn penalty, for pawns which are neither isolated or backward
+ const Score Unsupported = S(20, 10);
// Connected pawn bonus by opposed, phalanx, twice supported and rank
Score Connected[2][2][2][RANK_NB];
+
+ // Doubled pawn penalty by file
+ const Score Doubled[FILE_NB] = {
+ S(13, 43), S(20, 48), S(23, 48), S(23, 48),
+ S(23, 48), S(23, 48), S(20, 48), S(13, 43) };
- // Levers bonus by rank
+ // Lever bonus by rank
const Score Lever[RANK_NB] = {
- S( 0, 0), S( 0, 0), S(0, 0), S(0, 0),
- S(20,20), S(40,40), S(0, 0), S(0, 0) };
-
- // Unsupported pawn penalty
- const Score UnsupportedPawnPenalty = S(20, 10);
+ S( 0, 0), S( 0, 0), S(0, 0), S(0, 0),
+ S(20, 20), S(40, 40), S(0, 0), S(0, 0) };
+ // Center bind bonus, when two pawns controls the same central square
const Score CenterBind = S(16, 0);
// Weakness of our pawn shelter in front of the king by [distance from edge][rank]
const Value ShelterWeakness[][RANK_NB] = {
- { V( 97), V(21), V(26), V(51), V(87), V( 89), V( 99) },
- { V(120), V( 0), V(28), V(76), V(88), V(103), V(104) },
- { V(101), V( 7), V(54), V(78), V(77), V( 92), V(101) },
- { V( 80), V(11), V(44), V(68), V(87), V( 90), V(119) } };
+ { V( 97), V(21), V(26), V(51), V(87), V( 89), V( 99) },
+ { V(120), V( 0), V(28), V(76), V(88), V(103), V(104) },
+ { V(101), V( 7), V(54), V(78), V(77), V( 92), V(101) },
+ { V( 80), V(11), V(44), V(68), V(87), V( 90), V(119) } };
// Danger of enemy pawns moving toward our king by [type][distance from edge][rank]
const Value StormDanger[][4][RANK_NB] = {
- { { V( 0), V( 67), V( 134), V(38), V(32) },
- { V( 0), V( 57), V( 139), V(37), V(22) },
- { V( 0), V( 43), V( 115), V(43), V(27) },
- { V( 0), V( 68), V( 124), V(57), V(32) } },
- { { V(20), V( 43), V( 100), V(56), V(20) },
- { V(23), V( 20), V( 98), V(40), V(15) },
- { V(23), V( 39), V( 103), V(36), V(18) },
- { V(28), V( 19), V( 108), V(42), V(26) } },
- { { V( 0), V( 0), V( 75), V(14), V( 2) },
- { V( 0), V( 0), V( 150), V(30), V( 4) },
- { V( 0), V( 0), V( 160), V(22), V( 5) },
- { V( 0), V( 0), V( 166), V(24), V(13) } },
- { { V( 0), V(-283), V(-281), V(57), V(31) },
- { V( 0), V( 58), V( 141), V(39), V(18) },
- { V( 0), V( 65), V( 142), V(48), V(32) },
- { V( 0), V( 60), V( 126), V(51), V(19) } } };
+ { { V( 0), V( 67), V( 134), V(38), V(32) },
+ { V( 0), V( 57), V( 139), V(37), V(22) },
+ { V( 0), V( 43), V( 115), V(43), V(27) },
+ { V( 0), V( 68), V( 124), V(57), V(32) } },
+ { { V(20), V( 43), V( 100), V(56), V(20) },
+ { V(23), V( 20), V( 98), V(40), V(15) },
+ { V(23), V( 39), V( 103), V(36), V(18) },
+ { V(28), V( 19), V( 108), V(42), V(26) } },
+ { { V( 0), V( 0), V( 75), V(14), V( 2) },
+ { V( 0), V( 0), V( 150), V(30), V( 4) },
+ { V( 0), V( 0), V( 160), V(22), V( 5) },
+ { V( 0), V( 0), V( 166), V(24), V(13) } },
+ { { V( 0), V(-283), V(-281), V(57), V(31) },
+ { V( 0), V( 58), V( 141), V(39), V(18) },
+ { V( 0), V( 65), V( 142), V(48), V(32) },
+ { V( 0), V( 60), V( 126), V(51), V(19) } } };
// Max bonus for king safety. Corresponds to start position with all the pawns
// in front of the king and no enemy pawn on the horizon.
assert(opposed | passed | (pawn_attack_span(Us, s) & theirPawns));
// Passed pawns will be properly scored in evaluation because we need
- // full attack info to evaluate passed pawns. Only the frontmost passed
+ // full attack info to evaluate them. Only the frontmost passed
// pawn on each file is considered a true passed pawn.
if (passed && !doubled)
e->passedPawns[Us] |= s;
score -= Backward[opposed];
else if (!supported)
- score -= UnsupportedPawnPenalty;
+ score -= Unsupported;
if (connected)
score += Connected[opposed][!!phalanx][more_than_one(supported)][relative_rank(Us, s)];
b = e->semiopenFiles[Us] ^ 0xFF;
e->pawnSpan[Us] = b ? int(msb(b) - lsb(b)) : 0;
- // Center binds: Two pawns controlling the same central square
b = shift_bb<Right>(ourPawns) & shift_bb<Left>(ourPawns) & CenterBindMask;
- score += popcount<Max15>(b) * CenterBind;
+ score += CenterBind * popcount<Max15>(b);
return score;
}