X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=4187117b7df52d1150bc12594f9960a28d36d417;hb=7a9f67747f23e837a8691ba9e6e4f0d1fdafff73;hp=becaee3a20a0bd4d734b90c9c5544984a994061f;hpb=77e2b915e1e4f2469a414712e52b469633fb3273;p=stockfish diff --git a/src/search.cpp b/src/search.cpp index becaee3a..4187117b 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -72,7 +72,7 @@ namespace { Depth reduction(bool i, Depth d, int mn, Value delta, Value rootDelta) { int r = Reductions[d] * Reductions[mn]; - return (r + 1449 - int(delta) * 1032 / int(rootDelta)) / 1024 + (!i && r > 941); + return (r + 1449 - int(delta) * 937 / int(rootDelta)) / 1024 + (!i && r > 941); } constexpr int futility_move_count(bool improving, Depth depth) { @@ -82,7 +82,7 @@ namespace { // History and stats update bonus, based on depth int stat_bonus(Depth d) { - return std::min(340 * d - 470, 1855); + return std::min(341 * d - 470, 1710); } // Add a small random component to draw evaluations to avoid 3-fold blindness @@ -290,15 +290,17 @@ void Thread::search() { bestValue = delta = alpha = -VALUE_INFINITE; beta = VALUE_INFINITE; - optimism[us] = optimism[~us] = VALUE_ZERO; + optimism[WHITE] = optimism[BLACK] = VALUE_ZERO; if (mainThread) { - int rootComplexity; - Eval::evaluate(rootPos, &rootComplexity); - - mainThread->complexity = std::min(1.03 + (rootComplexity - 241) / 1552.0, 1.45); + if (!rootPos.checkers()) + { + int rootComplexity; + Eval::evaluate(rootPos, &rootComplexity); + mainThread->complexity = std::min(1.03 + (rootComplexity - 241) / 1552.0, 1.45); + } if (mainThread->bestPreviousScore == VALUE_INFINITE) for (int i = 0; i < 4; ++i) @@ -775,7 +777,7 @@ namespace { // Step 7. Razoring (~1 Elo). // If eval is really low check with qsearch if it can exceed alpha, if it can't, // return a fail low. - if (eval < alpha - 426 - 252 * depth * depth) + if (eval < alpha - 426 - 256 * depth * depth) { value = qsearch(pos, ss, alpha - 1, alpha); if (value < alpha) @@ -797,7 +799,7 @@ namespace { && (ss-1)->statScore < 18755 && eval >= beta && eval >= ss->staticEval - && ss->staticEval >= beta - 19 * depth - improvement / 13 + 253 + complexity / 25 + && ss->staticEval >= beta - 20 * depth - improvement / 13 + 253 + complexity / 25 && !excludedMove && pos.non_pawn_material(us) && (ss->ply >= thisThread->nmpMinPly || us != thisThread->nmpColor)) @@ -805,7 +807,7 @@ namespace { assert(eval - beta >= 0); // Null move dynamic reduction based on depth, eval and complexity of position - Depth R = std::min(int(eval - beta) / 168, 6) + depth / 3 + 4 - (complexity > 825); + Depth R = std::min(int(eval - beta) / 172, 6) + depth / 3 + 4 - (complexity > 825); ss->currentMove = MOVE_NULL; ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0]; @@ -1016,16 +1018,18 @@ moves_loop: // When in check, search starts here { if (depth < 2 - capture) continue; - // don't prune move if a heavy enemy piece (KQR) is under attack after the exchanges - Bitboard leftEnemies = (pos.pieces(~us, QUEEN, ROOK) | pos.pieces(~us, KING)) & occupied; + // Don't prune the move if opp. King/Queen/Rook is attacked by a slider after the exchanges. + // Since in see_ge we don't update occupied when the king recaptures, we also don't prune the + // move when the opp. King gets a discovered slider attack DURING the exchanges. + Bitboard leftEnemies = pos.pieces(~us, ROOK, QUEEN, KING) & occupied; Bitboard attacks = 0; occupied |= to_sq(move); while (leftEnemies && !attacks) { Square sq = pop_lsb(leftEnemies); - attacks |= pos.attackers_to(sq, occupied) & pos.pieces(us) & occupied; - // exclude Queen/Rook(s) which were already threatened before SEE - if (attacks && (sq != pos.square(~us) && (pos.attackers_to(sq, pos.pieces()) & pos.pieces(us)))) + attacks = pos.attackers_to(sq, occupied) & pos.pieces(us) & occupied; + // Exclude Queen/Rook(s) which were already threatened before SEE + if (attacks && sq != pos.square(~us) && (pos.attackers_to(sq, pos.pieces()) & pos.pieces(us))) attacks = 0; } if (!attacks) @@ -1057,7 +1061,7 @@ moves_loop: // When in check, search starts here lmrDepth = std::max(lmrDepth, 0); // Prune moves with negative SEE (~4 Elo) - if (!pos.see_ge(move, Value(-24 * lmrDepth * lmrDepth - 15 * lmrDepth))) + if (!pos.see_ge(move, Value(-24 * lmrDepth * lmrDepth - 16 * lmrDepth))) continue; } } @@ -1193,10 +1197,10 @@ moves_loop: // When in check, search starts here + (*contHist[0])[movedPiece][to_sq(move)] + (*contHist[1])[movedPiece][to_sq(move)] + (*contHist[3])[movedPiece][to_sq(move)] - - 4182; + - 4082; // Decrease/increase reduction for moves with a good/bad history (~25 Elo) - r -= ss->statScore / (11791 + 3992 * (depth > 6 && depth < 19)); + r -= ss->statScore / (11079 + 4626 * (depth > 6 && depth < 19)); // Step 17. Late moves reduction / extension (LMR, ~117 Elo) // We use various heuristics for the sons of a node after the first son has @@ -1257,6 +1261,9 @@ moves_loop: // When in check, search starts here (ss+1)->pv[0] = MOVE_NONE; value = -search(pos, ss+1, -beta, -alpha, newDepth, false); + + if (moveCount > 1 && newDepth >= depth && !capture) + update_continuation_histories(ss, movedPiece, to_sq(move), -stat_bonus(newDepth)); } // Step 19. Undo move @@ -1330,16 +1337,17 @@ moves_loop: // When in check, search starts here if (PvNode && value < beta) // Update alpha! Always alpha < beta { - alpha = value; - // Reduce other moves if we have found at least one score improvement (~1 Elo) if ( depth > 1 - && depth < 6 - && beta < 10534 - && alpha > -10534) + && ( (improving && complexity > 971) + || value < (5 * alpha + 75 * beta) / 87 + || depth < 6) + && beta < 12535 + && value > -12535) depth -= 1; assert(depth > 0); + alpha = value; } else {