Pawns::Entry* pi;
};
-
- // Evaluation weights, indexed by the corresponding evaluation term
- enum { PawnStructure, PassedPawns, Space, KingSafety };
-
- const struct Weight { int mg, eg; } Weights[] = {
- {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);
- }
-
-
#define V(v) Value(v)
#define S(mg, eg) make_score(mg, eg)
// 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.
const Value Passed[][RANK_NB] = {
- { V(0), V( 1), V(34), V(90), V(214), V(328) },
- { V(7), V(14), V(37), V(63), V(134), V(189) }
+ { V(5), V( 5), V(31), V(73), V(166), V(252) },
+ { V(7), V(14), V(38), V(73), V(166), V(252) }
};
// 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)
+ S( 9, 10), S( 2, 10), S( 1, -8), S(-20,-12),
+ S(-20,-12), S( 1, -8), S( 2, 10), S( 9, 10)
};
// Assorted bonuses and penalties used by evaluation
const Score TrappedRook = S(92, 0);
const Score Checked = S(20, 20);
const Score ThreatByHangingPawn = S(70, 63);
+ const Score LooseEnemies = S( 0, 25);
const Score Hanging = S(48, 28);
const Score ThreatByPawnPush = S(31, 19);
const Score Unstoppable = S( 0, 20);
b2 = pos.attacks_from<BISHOP>(ksq) & safe;
// Enemy queen safe checks
- b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
- if (b)
- {
- attackUnits += QueenCheck * popcount<Max15>(b);
- score -= Checked;
- }
+ if ((b1 | b2) & ei.attackedBy[Them][QUEEN])
+ attackUnits += QueenCheck, score -= Checked;
// Enemy rooks safe checks
- b = b1 & ei.attackedBy[Them][ROOK];
- if (b)
- {
- attackUnits += RookCheck * popcount<Max15>(b);
- score -= Checked;
- }
+ if (b1 & ei.attackedBy[Them][ROOK])
+ attackUnits += RookCheck, score -= Checked;
// Enemy bishops safe checks
- b = b2 & ei.attackedBy[Them][BISHOP];
- if (b)
- {
- attackUnits += BishopCheck * popcount<Max15>(b);
- score -= Checked;
- }
+ if (b2 & ei.attackedBy[Them][BISHOP])
+ attackUnits += BishopCheck, score -= Checked;
// Enemy knights safe checks
- b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
- if (b)
- {
- attackUnits += KnightCheck * popcount<Max15>(b);
- score -= Checked;
- }
+ if (pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe)
+ attackUnits += KnightCheck, score -= Checked;
// Finally, extract the king danger score from the KingDanger[]
// array and subtract the score from the evaluation.
}
- // evaluate_threats() assigns bonuses according to the types of the attacking
+ // evaluate_threats() assigns bonuses according to the types of the attacking
// and the attacked pieces.
template<Color Us, bool DoTrace>
Bitboard b, weak, defended, safeThreats;
Score score = SCORE_ZERO;
+ // Small bonus if the opponent has loose pawns or pieces
+ if ( (pos.pieces(Them) ^ pos.pieces(Them, QUEEN, KING))
+ & ~(ei.attackedBy[Us][ALL_PIECES] | ei.attackedBy[Them][ALL_PIECES]))
+ score += LooseEnemies;
+
// Non-pawn enemies attacked by a pawn
weak = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Us][PAWN];
mbonus += k * rr, ebonus += k * rr;
}
else if (pos.pieces(Us) & blockSq)
- mbonus += rr * 3 + r * 2 + 3, ebonus += rr + r * 2;
+ mbonus += rr + r * 2, ebonus += rr + r * 2;
} // rr != 0
if (pos.count<PAWN>(Us) < pos.count<PAWN>(Them))
}
if (DoTrace)
- Trace::add(PASSED, Us, score * Weights[PassedPawns]);
+ Trace::add(PASSED, Us, score);
// Add the scores to the middlegame and endgame eval
- return score * Weights[PassedPawns];
+ return score;
}
int weight = pos.count<KNIGHT>(Us) + pos.count<BISHOP>(Us)
+ pos.count<KNIGHT>(Them) + pos.count<BISHOP>(Them);
- return make_score(bonus * weight * weight, 0);
+ return make_score(bonus * weight * weight * 2 / 11, 0);
}
// status of the players.
Score evaluate_initiative(const Position& pos, int asymmetry, Value eg) {
- int kingDistance = distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK));
+ int kingDistance = distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK))
+ - distance<Rank>(pos.square<KING>(WHITE), pos.square<KING>(BLACK));
int pawns = pos.count<PAWN>(WHITE) + pos.count<PAWN>(BLACK);
// Compute the initiative bonus for the attacking side
- int initiative = 8 * (pawns + asymmetry + kingDistance - 15);
+ int initiative = 8 * (asymmetry + kingDistance - 15) + 12 * pawns;
// Now apply the bonus: note that we find the attacking side by extracting
// the sign of the endgame value, and that we carefully cap the bonus so
// evaluate_scale_factor() computes the scale factor for the winning side
- ScaleFactor evaluate_scale_factor(const Position& pos, const EvalInfo& ei, Score score) {
+ ScaleFactor evaluate_scale_factor(const Position& pos, const EvalInfo& ei, Value eg) {
- Color strongSide = eg_value(score) > VALUE_DRAW ? WHITE : BLACK;
+ Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK;
ScaleFactor sf = ei.me->scale_factor(pos, strongSide);
// If we don't already have an unusual scale factor, check for certain
}
// Endings where weaker side can place his king in front of the opponent's
// pawns are drawish.
- else if ( abs(eg_value(score)) <= BishopValueEg
+ else if ( abs(eg) <= BishopValueEg
&& ei.pi->pawn_span(strongSide) <= 1
&& !pos.pawn_passed(~strongSide, pos.square<KING>(~strongSide)))
sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(51) : ScaleFactor(37);
// Probe the pawn hash table
ei.pi = Pawns::probe(pos);
- score += ei.pi->pawns_score() * Weights[PawnStructure];
+ score += ei.pi->pawns_score();
// Initialize attack and king safety bitboards
ei.attackedBy[WHITE][ALL_PIECES] = ei.attackedBy[BLACK][ALL_PIECES] = 0;
// Evaluate space for both sides, only during opening
if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222)
- score += ( evaluate_space<WHITE>(pos, ei)
- - evaluate_space<BLACK>(pos, ei)) * Weights[Space];
+ score += evaluate_space<WHITE>(pos, ei)
+ - evaluate_space<BLACK>(pos, ei);
// Evaluate position potential for the winning side
score += evaluate_initiative(pos, ei.pi->pawn_asymmetry(), eg_value(score));
// Evaluate scale factor for the winning side
- ScaleFactor sf = evaluate_scale_factor(pos, ei, score);
+ ScaleFactor sf = evaluate_scale_factor(pos, ei, eg_value(score));
// Interpolate between a middlegame and a (scaled by 'sf') endgame score
Value v = mg_value(score) * int(ei.me->game_phase())
{
Trace::add(MATERIAL, pos.psq_score());
Trace::add(IMBALANCE, ei.me->imbalance());
- Trace::add(PAWN, ei.pi->pawns_score() * Weights[PawnStructure]);
+ Trace::add(PAWN, ei.pi->pawns_score());
Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]);
- Trace::add(SPACE, evaluate_space<WHITE>(pos, ei) * Weights[Space]
- , evaluate_space<BLACK>(pos, ei) * Weights[Space]);
+ Trace::add(SPACE, evaluate_space<WHITE>(pos, ei)
+ , evaluate_space<BLACK>(pos, ei));
Trace::add(TOTAL, score);
}
void Eval::init() {
- const int MaxSlope = 8700;
- const int Peak = 1280000;
+ 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 * 27, t + MaxSlope));
- KingDanger[i] = make_score(t / 1000, 0) * Weights[KingSafety];
+ t = std::min(Peak, std::min(i * i - 16, t + MaxSlope));
+ KingDanger[i] = make_score(t * 268 / 7700, 0);
}
}
projects / stockfish / blobdiff