X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=edeed9c030446a9e015cf99218ce2a5ca402315b;hb=b82d93ece484f833c994b40d9eddd959ba20ef92;hp=f2e11e35b520ba4438e478b2a03b7feaaff03a7a;hpb=c4a1390f4e485b8b6a2cf43504a968a3c8a4317d;p=stockfish diff --git a/src/search.cpp b/src/search.cpp index f2e11e35..edeed9c0 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -260,6 +260,7 @@ void MainThread::search() { bestThread = Threads.get_best_thread(); bestPreviousScore = bestThread->rootMoves[0].score; + bestPreviousAverageScore = bestThread->rootMoves[0].averageScore; // Send again PV info if we have a new best thread if (bestThread != this) @@ -334,8 +335,10 @@ void Thread::search() { nodesLastExplosive = nodes; nodesLastNormal = nodes; - state = EXPLOSION_NONE; - trend = SCORE_ZERO; + state = EXPLOSION_NONE; + trend = SCORE_ZERO; + optimism[ us] = Value(25); + optimism[~us] = -optimism[us]; int searchAgainCounter = 0; @@ -381,11 +384,14 @@ void Thread::search() { alpha = std::max(prev - delta,-VALUE_INFINITE); beta = std::min(prev + delta, VALUE_INFINITE); - // Adjust trend based on root move's previousScore (dynamic contempt) - int tr = 113 * prev / (abs(prev) + 147); - + // Adjust trend and optimism based on root move's previousScore + int tr = sigmoid(prev, 0, 0, 147, 113, 1); trend = (us == WHITE ? make_score(tr, tr / 2) : -make_score(tr, tr / 2)); + + int opt = sigmoid(prev, 0, 25, 147, 14464, 256); + optimism[ us] = Value(opt); + optimism[~us] = -optimism[us]; } // Start with a small aspiration window and, in the case of a fail @@ -472,25 +478,26 @@ void Thread::search() { if (skill.enabled() && skill.time_to_pick(rootDepth)) skill.pick_best(multiPV); + // Use part of the gained time from a previous stable move for the current move + for (Thread* th : Threads) + { + totBestMoveChanges += th->bestMoveChanges; + th->bestMoveChanges = 0; + } + // Do we have time for the next iteration? Can we stop searching now? if ( Limits.use_time_management() && !Threads.stop && !mainThread->stopOnPonderhit) { - double fallingEval = (318 + 6 * (mainThread->bestPreviousScore - bestValue) + double fallingEval = (142 + 6 * (mainThread->bestPreviousScore - bestValue) + + 6 * (mainThread->bestPreviousAverageScore - bestValue) + 6 * (mainThread->iterValue[iterIdx] - bestValue)) / 825.0; fallingEval = std::clamp(fallingEval, 0.5, 1.5); // If the bestMove is stable over several iterations, reduce time accordingly timeReduction = lastBestMoveDepth + 9 < completedDepth ? 1.92 : 0.95; double reduction = (1.47 + mainThread->previousTimeReduction) / (2.32 * timeReduction); - - // Use part of the gained time from a previous stable move for the current move - for (Thread* th : Threads) - { - totBestMoveChanges += th->bestMoveChanges; - th->bestMoveChanges = 0; - } double bestMoveInstability = 1.073 + std::max(1.0, 2.25 - 9.9 / rootDepth) * totBestMoveChanges / Threads.size(); double totalTime = Time.optimum() * fallingEval * reduction * bestMoveInstability; @@ -796,7 +803,7 @@ namespace { // Use static evaluation difference to improve quiet move ordering if (is_ok((ss-1)->currentMove) && !(ss-1)->inCheck && !priorCapture) { - int bonus = std::clamp(-depth * 4 * int((ss-1)->staticEval + ss->staticEval), -1000, 1000); + int bonus = std::clamp(-16 * int((ss-1)->staticEval + ss->staticEval), -2000, 2000); thisThread->mainHistory[~us][from_to((ss-1)->currentMove)] << bonus; } @@ -812,7 +819,7 @@ namespace { // Step 7. Futility pruning: child node (~50 Elo). // The depth condition is important for mate finding. - if ( !PvNode + if ( !ss->ttPv && depth < 9 && eval - futility_margin(depth, improving) >= beta && eval < 15000) // 50% larger than VALUE_KNOWN_WIN, but smaller than TB wins. @@ -1049,17 +1056,23 @@ moves_loop: // When in check, search starts here } else { + int history = (*contHist[0])[movedPiece][to_sq(move)] + + (*contHist[1])[movedPiece][to_sq(move)] + + (*contHist[3])[movedPiece][to_sq(move)]; + // Continuation history based pruning (~20 Elo) - if (lmrDepth < 5 - && (*contHist[0])[movedPiece][to_sq(move)] - + (*contHist[1])[movedPiece][to_sq(move)] - + (*contHist[3])[movedPiece][to_sq(move)] < -3000 * depth + 3000) + if ( lmrDepth < 5 + && history < -3000 * depth + 3000) continue; + history += thisThread->mainHistory[us][from_to(move)]; + + lmrDepth = std::max(0, lmrDepth - (beta - alpha < thisThread->rootDelta / 4)); + // Futility pruning: parent node (~5 Elo) if ( !ss->inCheck && lmrDepth < 8 - && ss->staticEval + 172 + 145 * lmrDepth <= alpha) + && ss->staticEval + 142 + 139 * lmrDepth + history / 64 <= alpha) continue; // Prune moves with negative SEE (~20 Elo) @@ -1164,24 +1177,20 @@ moves_loop: // When in check, search starts here { Depth r = reduction(improving, depth, moveCount, rangeReduction > 2); - // Decrease reduction if on the PV (~2 Elo) + // Decrease reduction at some PvNodes (~2 Elo) if ( PvNode - && bestMoveCount <= 3) + && bestMoveCount <= 3 + && beta - alpha >= thisThread->rootDelta / 4) r--; - // Increases reduction for PvNodes that have small window - if (PvNode && beta - alpha < thisThread->rootDelta / 4) - r++; - // Decrease reduction if position is or has been on the PV // and node is not likely to fail low. (~3 Elo) if ( ss->ttPv && !likelyFailLow) r -= 2; - // Increase reduction at root and non-PV nodes when the best move does not change frequently - if ( (rootNode || !PvNode) - && thisThread->bestMoveChanges <= 2) + // Increase reduction at non-PV nodes + if (!PvNode) r++; // Decrease reduction if opponent's move count is high (~1 Elo) @@ -1371,7 +1380,15 @@ moves_loop: // When in check, search starts here // Bonus for prior countermove that caused the fail low else if ( (depth >= 3 || PvNode) && !priorCapture) - update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth) * (1 + (PvNode || cutNode))); + { + //Assign extra bonus if current node is PvNode or cutNode + //or fail low was really bad + bool extraBonus = PvNode + || cutNode + || bestValue < alpha - 94 * depth; + + update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth) * (1 + extraBonus)); + } if (PvNode) bestValue = std::min(bestValue, maxValue);