std::map<Move, int64_t> votes;
Value minScore = this->rootMoves[0].score;
- // Find out minimum score and reset votes for moves which can be voted
+ // Find out minimum score
for (Thread* th: Threads)
minScore = std::min(minScore, th->rootMoves[0].score);
votes[th->rootMoves[0].pv[0]] +=
(th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
- if (votes[th->rootMoves[0].pv[0]] > votes[bestThread->rootMoves[0].pv[0]])
+ if (bestThread->rootMoves[0].score >= VALUE_MATE_IN_MAX_PLY)
+ {
+ // Make sure we pick the shortest mate
+ if (th->rootMoves[0].score > bestThread->rootMoves[0].score)
+ bestThread = th;
+ }
+ else if ( th->rootMoves[0].score >= VALUE_MATE_IN_MAX_PLY
+ || votes[th->rootMoves[0].pv[0]] > votes[bestThread->rootMoves[0].pv[0]])
bestThread = th;
}
}
continue;
// Prune moves with negative SEE (~10 Elo)
- if (!pos.see_ge(move, Value(-29 * lmrDepth * lmrDepth)))
+ if (!pos.see_ge(move, Value(-(31 - std::min(lmrDepth, 18)) * lmrDepth * lmrDepth)))
continue;
}
else if ( (!givesCheck || !extension)
+ (*contHist[3])[movedPiece][to_sq(move)]
- 4000;
+ // Reset statScore to zero if negative and most stats shows >= 0
+ if ( ss->statScore < 0
+ && (*contHist[0])[movedPiece][to_sq(move)] >= 0
+ && (*contHist[1])[movedPiece][to_sq(move)] >= 0
+ && thisThread->mainHistory[us][from_to(move)] >= 0)
+ ss->statScore = 0;
+
// Decrease/increase reduction by comparing opponent's stat score (~10 Elo)
if (ss->statScore >= 0 && (ss-1)->statScore < 0)
r -= ONE_PLY;
int bonus = value > alpha ? stat_bonus(newDepth)
: -stat_bonus(newDepth);
+ if (move == ss->killers[0])
+ bonus += bonus / 4;
+
update_continuation_histories(ss, movedPiece, to_sq(move), bonus);
}
}