// happen in Chess960 games.
const Score TrappedBishopA1H1Penalty = make_score(100, 100);
+ // Penalty for BNR that is not defended by anything
+ const Score UndefendedPiecePenalty = make_score(25, 10);
+
// 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
std::stringstream TraceStream;
enum TracedType {
- PST = 8, IMBALANCE = 9, MOBILITY = 10, THREAT = 11,
- PASSED = 12, UNSTOPPABLE = 13, SPACE = 14, TOTAL = 15
+ PST = 8, IMBALANCE = 9, MOBILITY = 10, THREAT = 11,
+ PASSED = 12, UNSTOPPABLE = 13, SPACE = 14, TOTAL = 15
};
// Function prototypes
inline Score apply_weight(Score v, Score weight);
Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf);
Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
- void init_safety();
double to_cp(Value v);
void trace_add(int idx, Score term_w, Score term_b = SCORE_ZERO);
+ void trace_row(const char* name, int idx);
}
-/// evaluate() is the main evaluation function. It always computes two
-/// values, an endgame score and a middle game score, and interpolates
-/// between them based on the remaining material.
-Value evaluate(const Position& pos, Value& margin) { return do_evaluate<false>(pos, margin); }
+namespace Eval {
+
+ Color RootColor;
+
+ /// evaluate() is the main evaluation function. It always computes two
+ /// values, an endgame score and a middle game score, and interpolates
+ /// between them based on the remaining material.
+
+ Value evaluate(const Position& pos, Value& margin) {
+ return do_evaluate<false>(pos, margin);
+ }
+
+
+ /// init() computes evaluation weights from the corresponding UCI parameters
+ /// and setup king tables.
+
+ void init() {
+
+ Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
+ Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
+ Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
+ Weights[KingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
+ Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
+
+ // King safety is asymmetrical. Our king danger level is weighted by
+ // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
+ // If running in analysis mode, make sure we use symmetrical king safety. We
+ // do this by replacing both Weights[kingDangerUs] and Weights[kingDangerThem]
+ // by their average.
+ if (Options["UCI_AnalyseMode"])
+ Weights[KingDangerUs] = Weights[KingDangerThem] = (Weights[KingDangerUs] + Weights[KingDangerThem]) / 2;
+
+ const int MaxSlope = 30;
+ const int Peak = 1280;
+
+ for (int t = 0, i = 1; i < 100; i++)
+ {
+ t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope));
+
+ KingDangerTable[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]);
+ KingDangerTable[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]);
+ }
+ }
+
+
+ /// trace() is like evaluate() but instead of a value returns a string suitable
+ /// to be print on stdout with the detailed descriptions and values of each
+ /// evaluation term. Used mainly for debugging.
+
+ std::string trace(const Position& pos) {
+
+ Value margin;
+ std::string totals;
+
+ RootColor = pos.side_to_move();
+
+ TraceStream.str("");
+ TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
+ memset(TracedScores, 0, 2 * 16 * sizeof(Score));
+
+ do_evaluate<true>(pos, margin);
+
+ totals = TraceStream.str();
+ TraceStream.str("");
+
+ TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
+ << " | MG EG | MG EG | MG EG \n"
+ << "---------------------+-------------+-------------+---------------\n";
+
+ trace_row("Material, PST, Tempo", PST);
+ trace_row("Material imbalance", IMBALANCE);
+ trace_row("Pawns", PAWN);
+ trace_row("Knights", KNIGHT);
+ trace_row("Bishops", BISHOP);
+ trace_row("Rooks", ROOK);
+ trace_row("Queens", QUEEN);
+ trace_row("Mobility", MOBILITY);
+ trace_row("King safety", KING);
+ trace_row("Threats", THREAT);
+ trace_row("Passed pawns", PASSED);
+ trace_row("Unstoppable pawns", UNSTOPPABLE);
+ trace_row("Space", SPACE);
+
+ TraceStream << "---------------------+-------------+-------------+---------------\n";
+ trace_row("Total", TOTAL);
+ TraceStream << totals;
+
+ return TraceStream.str();
+ }
+
+} // namespace Eval
+
namespace {
template<bool Trace>
Value do_evaluate(const Position& pos, Value& margin) {
+ assert(!pos.in_check());
+
EvalInfo ei;
Value margins[2];
Score score, mobilityWhite, mobilityBlack;
- assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
- assert(!pos.in_check());
-
// Initialize score by reading the incrementally updated scores included
// in the position object (material + piece square tables).
score = pos.value();
return pos.side_to_move() == WHITE ? v : -v;
}
-} // namespace
-
-
-/// read_weights() reads evaluation weights from the corresponding UCI parameters
-
-void read_evaluation_uci_options(Color us) {
-
- // King safety is asymmetrical. Our king danger level is weighted by
- // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
- const int kingDangerUs = (us == WHITE ? KingDangerUs : KingDangerThem);
- const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs);
-
- Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
- Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
- Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
- Weights[kingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
- Weights[kingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
-
- // If running in analysis mode, make sure we use symmetrical king safety. We do this
- // by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] by their average.
- if (Options["UCI_AnalyseMode"])
- Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2;
-
- init_safety();
-}
-
-
-namespace {
// init_eval_info() initializes king bitboards for given color adding
// pawn attacks. To be done at the beginning of the evaluation.
if (Piece == KNIGHT || Piece == QUEEN)
b = pos.attacks_from<Piece>(s);
else if (Piece == BISHOP)
- b = attacks_bb<BISHOP>(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us));
+ b = attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(QUEEN, Us));
else if (Piece == ROOK)
- b = attacks_bb<ROOK>(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us));
+ b = attacks_bb<ROOK>(s, pos.pieces() ^ pos.pieces(ROOK, QUEEN, Us));
else
assert(false);
if ( (Piece == BISHOP || Piece == ROOK || Piece == QUEEN)
&& (PseudoAttacks[Piece][pos.king_square(Them)] & s))
{
- b = BetweenBB[s][pos.king_square(Them)] & pos.occupied_squares();
+ b = BetweenBB[s][pos.king_square(Them)] & pos.pieces();
assert(b);
- if (!(b & (b - 1)) && (b & pos.pieces(Them)))
- score += ThreatBonus[Piece][type_of(pos.piece_on(first_1(b)))] / 2;
+ if (single_bit(b) && (b & pos.pieces(Them)))
+ score += ThreatBonus[Piece][type_of(pos.piece_on(first_1(b)))];
}
// Decrease score if we are attacked by an enemy pawn. Remaining part
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Bitboard b;
+ Bitboard b, undefended, undefendedMinors, weakEnemies;
Score score = SCORE_ZERO;
+ // Undefended pieces get penalized even if not under attack
+ undefended = pos.pieces(Them) & ~ei.attackedBy[Them][0];
+ undefendedMinors = undefended & (pos.pieces(BISHOP) | pos.pieces(KNIGHT));
+
+ if (undefendedMinors)
+ score += single_bit(undefendedMinors) ? UndefendedPiecePenalty
+ : UndefendedPiecePenalty * 2;
+ if (undefended & pos.pieces(ROOK))
+ score += UndefendedPiecePenalty;
+
// Enemy pieces not defended by a pawn and under our attack
- Bitboard weakEnemies = pos.pieces(Them)
- & ~ei.attackedBy[Them][PAWN]
- & ei.attackedBy[Us][0];
+ weakEnemies = pos.pieces(Them)
+ & ~ei.attackedBy[Them][PAWN]
+ & ei.attackedBy[Us][0];
+
if (!weakEnemies)
- return SCORE_ZERO;
+ return score;
// Add bonus according to type of attacked enemy piece and to the
// type of attacking piece, from knights to queens. Kings are not
int attackUnits;
const Square ksq = pos.king_square(Us);
- // King shelter
- Score score = ei.pi->king_shelter<Us>(pos, ksq);
+ // King shelter and enemy pawns storm
+ Score score = ei.pi->king_safety<Us>(pos, ksq);
// King safety. This is quite complicated, and is almost certainly far
// from optimally tuned.
attackUnits = std::min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
+ 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
+ InitKingDanger[relative_square(Us, ksq)]
- - mg_value(ei.pi->king_shelter<Us>(pos, ksq)) / 32;
+ - mg_value(ei.pi->king_safety<Us>(pos, ksq)) / 32;
// Analyse enemy's safe queen contact checks. First find undefended
// squares around the king attacked by enemy queen...
// value that will be used for pruning because this value can sometimes
// be very big, and so capturing a single attacking piece can therefore
// result in a score change far bigger than the value of the captured piece.
- score -= KingDangerTable[Us][attackUnits];
- margins[Us] += mg_value(KingDangerTable[Us][attackUnits]);
+ score -= KingDangerTable[Us == Eval::RootColor][attackUnits];
+ margins[Us] += mg_value(KingDangerTable[Us == Eval::RootColor][attackUnits]);
}
if (Trace)
// Opponent king cannot block because path is defended and position
// is not in check. So only friendly pieces can be blockers.
assert(!pos.in_check());
- assert((queeningPath & pos.occupied_squares()) == (queeningPath & pos.pieces(c)));
+ assert((queeningPath & pos.pieces()) == (queeningPath & pos.pieces(c)));
// Add moves needed to free the path from friendly pieces and retest condition
movesToGo += popcount<Max15>(queeningPath & pos.pieces(c));
}
- // init_safety() initizes the king safety evaluation, based on UCI
- // parameters. It is called from read_weights().
-
- void init_safety() {
-
- const Value MaxSlope = Value(30);
- const Value Peak = Value(1280);
- Value t[100];
-
- // First setup the base table
- for (int i = 0; i < 100; i++)
- {
- t[i] = Value(int(0.4 * i * i));
-
- if (i > 0)
- t[i] = std::min(t[i], t[i - 1] + MaxSlope);
-
- t[i] = std::min(t[i], Peak);
- }
-
- // Then apply the weights and get the final KingDangerTable[] array
- for (Color c = WHITE; c <= BLACK; c++)
- for (int i = 0; i < 100; i++)
- KingDangerTable[c][i] = apply_weight(make_score(t[i], 0), Weights[KingDangerUs + c]);
- }
-
-
// A couple of little helpers used by tracing code, to_cp() converts a value to
// a double in centipawns scale, trace_add() stores white and black scores.
void trace_add(int idx, Score wScore, Score bScore) {
- TracedScores[WHITE][idx] = wScore;
- TracedScores[BLACK][idx] = bScore;
+ TracedScores[WHITE][idx] = wScore;
+ TracedScores[BLACK][idx] = bScore;
}
+
// trace_row() is an helper function used by tracing code to register the
// values of a single evaluation term.
- void trace_row(const char *name, int idx) {
+ void trace_row(const char* name, int idx) {
Score wScore = TracedScores[WHITE][idx];
Score bScore = TracedScores[BLACK][idx];
}
}
}
-
-
-/// trace_evaluate() is like evaluate() but instead of a value returns a string
-/// suitable to be print on stdout with the detailed descriptions and values of
-/// each evaluation term. Used mainly for debugging.
-
-std::string trace_evaluate(const Position& pos) {
-
- Value margin;
- std::string totals;
-
- TraceStream.str("");
- TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
- memset(TracedScores, 0, 2 * 16 * sizeof(Score));
-
- do_evaluate<true>(pos, margin);
-
- totals = TraceStream.str();
- TraceStream.str("");
-
- TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
- << " | MG EG | MG EG | MG EG \n"
- << "---------------------+-------------+-------------+---------------\n";
-
- trace_row("Material, PST, Tempo", PST);
- trace_row("Material imbalance", IMBALANCE);
- trace_row("Pawns", PAWN);
- trace_row("Knights", KNIGHT);
- trace_row("Bishops", BISHOP);
- trace_row("Rooks", ROOK);
- trace_row("Queens", QUEEN);
- trace_row("Mobility", MOBILITY);
- trace_row("King safety", KING);
- trace_row("Threats", THREAT);
- trace_row("Passed pawns", PASSED);
- trace_row("Unstoppable pawns", UNSTOPPABLE);
- trace_row("Space", SPACE);
-
- TraceStream << "---------------------+-------------+-------------+---------------\n";
- trace_row("Total", TOTAL);
- TraceStream << totals;
-
- return TraceStream.str();
-}
projects / stockfish / blobdiff