/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include <algorithm>
#include <cassert>
+#include <cstring> // For std::memset
#include <iomanip>
#include <sstream>
#include "evaluate.h"
#include "material.h"
#include "pawns.h"
-#include "thread.h"
namespace {
// Evaluation weights, indexed by evaluation term
enum { Mobility, PawnStructure, PassedPawns, Space, KingSafety };
const struct Weight { int mg, eg; } Weights[] = {
- {289, 344}, {233, 201}, {221, 273}, {46, 0}, {318, 0}
+ {289, 344}, {233, 201}, {221, 273}, {46, 0}, {322, 0}
};
#define V(v) Value(v)
const Score TrappedRook = S(92, 0);
const Score Unstoppable = S( 0, 20);
const Score Hanging = S(31, 26);
+ const Score PawnAttackThreat = S(20, 20);
+ const Score PawnSafePush = S( 5 , 5);
// 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
// index to KingDanger[].
//
// KingAttackWeights[PieceType] contains king attack weights by piece type
- const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
+ const int KingAttackWeights[] = { 0, 0, 7, 5, 4, 1 };
// Bonuses for enemy's safe checks
- const int QueenContactCheck = 24;
- const int RookContactCheck = 16;
- const int QueenCheck = 12;
- const int RookCheck = 8;
- const int BishopCheck = 2;
- const int KnightCheck = 3;
+ const int QueenContactCheck = 89;
+ const int RookContactCheck = 71;
+ const int QueenCheck = 50;
+ const int RookCheck = 37;
+ const int BishopCheck = 6;
+ const int KnightCheck = 14;
// KingDanger[attackUnits] contains the actual king danger weighted
// scores, indexed by a calculated integer number.
- Score KingDanger[128];
+ Score KingDanger[512];
// apply_weight() weighs score 's' by weight 'w' trying to prevent overflow
Score apply_weight(Score s, const Weight& w) {
// number and types of the enemy's attacking pieces, the number of
// attacked and undefended squares around our king and the quality of
// the pawn shelter (current 'score' value).
- attackUnits = std::min(20, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
- + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
- + 2 * (ei.pinnedPieces[Us] != 0)
- - mg_value(score) / 32
- - !pos.count<QUEEN>(Them) * 15;
+ attackUnits = std::min(74, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them])
+ + 8 * ei.kingAdjacentZoneAttacksCount[Them]
+ + 25 * popcount<Max15>(undefended)
+ + 11 * (ei.pinnedPieces[Us] != 0)
+ - mg_value(score) / 8
+ - !pos.count<QUEEN>(Them) * 60;
// Analyse the enemy's safe queen contact checks. Firstly, find the
// undefended squares around the king reachable by the enemy queen...
// Finally, extract the king danger score from the KingDanger[]
// array and subtract the score from evaluation.
- score -= KingDanger[std::max(std::min(attackUnits, 99), 0)];
+ score -= KingDanger[std::max(std::min(attackUnits, 399), 0)];
}
if (Trace)
template<Color Us, bool Trace>
Score evaluate_threats(const Position& pos, const EvalInfo& ei) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Square Up = (Us == WHITE ? DELTA_N : DELTA_S);
+ const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE);
+ const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
+ const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB);
+ const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
enum { Defended, Weak };
enum { Minor, Major };
b = weak & ~ei.attackedBy[Them][ALL_PIECES];
if (b)
- score += more_than_one(b) ? Hanging * popcount<Max15>(b) : Hanging;
+ score += Hanging * popcount<Max15>(b);
b = weak & ei.attackedBy[Us][KING];
if (b)
score += more_than_one(b) ? KingOnMany : KingOnOne;
}
+ // Add a small bonus for safe pawn pushes
+ b = pos.pieces(Us, PAWN) & ~TRank7BB;
+ b = shift_bb<Up>(b | (shift_bb<Up>(b & TRank2BB) & ~pos.pieces()));
+
+ b &= ~pos.pieces()
+ & ~ei.attackedBy[Them][PAWN]
+ & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]);
+
+ if (b)
+ score += popcount<Full>(b) * PawnSafePush;
+
+ // Add another bonus if the pawn push attacks an enemy piece
+ b = (shift_bb<Left>(b) | shift_bb<Right>(b))
+ & pos.pieces(Them)
+ & ~ei.attackedBy[Us][PAWN];
+
+ if (b)
+ score += popcount<Max15>(b) * PawnAttackThreat;
+
if (Trace)
Tracing::write(Tracing::THREAT, Us, score);
// space evaluation is a simple bonus based on the number of safe squares
// available for minor pieces on the central four files on ranks 2--4. Safe
// squares one, two or three squares behind a friendly pawn are counted
- // twice. Finally, the space bonus is scaled by a weight taken from the
- // material hash table. The aim is to improve play on game opening.
+ // twice. Finally, the space bonus is multiplied by a weight. The aim is to
+ // improve play on game opening.
template<Color Us>
- Score evaluate_space(const Position& pos, const EvalInfo& ei, Score weight) {
+ Score evaluate_space(const Position& pos, const EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);
// Count safe + (behind & safe) with a single popcount
- return popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe)) * weight;
+ int bonus = popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
+ 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);
}
EvalInfo ei;
Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO };
- Thread* thisThread = pos.this_thread();
// Initialize score by reading the incrementally updated scores included
// in the position object (material + piece square tables).
score = pos.psq_score();
// Probe the material hash table
- ei.mi = Material::probe(pos, thisThread->materialTable, thisThread->endgames);
+ ei.mi = Material::probe(pos);
score += ei.mi->imbalance();
// If we have a specialized evaluation function for the current material
return ei.mi->evaluate(pos);
// Probe the pawn hash table
- ei.pi = Pawns::probe(pos, thisThread->pawnsTable);
+ ei.pi = Pawns::probe(pos);
score += apply_weight(ei.pi->pawns_score(), Weights[PawnStructure]);
// Initialize attack and king safety bitboards
score -= int(relative_rank(BLACK, frontmost_sq(BLACK, b))) * Unstoppable;
}
- // Evaluate space for both sides, only in middlegame
- if (ei.mi->space_weight())
+ // Evaluate space for both sides, only during opening
+ if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 2 * QueenValueMg + 4 * RookValueMg + 2 * KnightValueMg)
{
- Score s = evaluate_space<WHITE>(pos, ei, ei.mi->space_weight())
- - evaluate_space<BLACK>(pos, ei, ei.mi->space_weight());
-
+ Score s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
score += apply_weight(s, Weights[Space]);
}
Tracing::write(PAWN, ei.pi->pawns_score());
Tracing::write(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility])
, apply_weight(mobility[BLACK], Weights[Mobility]));
- Score w = evaluate_space<WHITE>(pos, ei, ei.mi->space_weight());
- Score b = evaluate_space<BLACK>(pos, ei, ei.mi->space_weight());
- Tracing::write(Tracing::SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
+ Tracing::write(Tracing::SPACE, apply_weight(evaluate_space<WHITE>(pos, ei), Weights[Space])
+ , apply_weight(evaluate_space<BLACK>(pos, ei), Weights[Space]));
Tracing::write(Tracing::TOTAL, score);
Tracing::ei = ei;
Tracing::sf = sf;
void init() {
- const double MaxSlope = 30;
- const double Peak = 1280;
+ const int MaxSlope = 8700;
+ const int Peak = 1280000;
+ int t = 0;
- for (int t = 0, i = 1; i < 100; ++i)
+ for (int i = 0; i < 400; ++i)
{
- t = int(std::min(Peak, std::min(0.4 * i * i, t + MaxSlope)));
- KingDanger[i] = apply_weight(make_score(t, 0), Weights[KingSafety]);
+ t = std::min(Peak, std::min(i * i * 27, t + MaxSlope));
+ KingDanger[i] = apply_weight(make_score(t / 1000, 0), Weights[KingSafety]);
}
}