From 54c696086c7e49de6deb133db9341263991f1154 Mon Sep 17 00:00:00 2001 From: PikaCat Date: Mon, 22 Jul 2024 22:47:25 +0800 Subject: [PATCH] Search tweaks --- src/search.cpp | 110 ++++++++++++++++++++++++------------------------- 1 file changed, 55 insertions(+), 55 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index 1fbd494e..a44b9ab0 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -53,7 +53,7 @@ namespace { // Futility margin Value futility_margin(Depth d, bool noTtCutNode, bool improving, bool oppWorsening) { - Value futilityMult = 174 - 28 * noTtCutNode; + Value futilityMult = 176 - 28 * noTtCutNode; Value improvingDeduction = improving * futilityMult * 2; Value worseningDeduction = oppWorsening * futilityMult / 3; @@ -73,10 +73,10 @@ Value to_corrected_static_eval(Value v, const Worker& w, const Position& pos) { } // History and stats update bonus, based on depth -int stat_bonus(Depth d) { return std::min(226 * d - 101, 1675); } +int stat_bonus(Depth d) { return std::min(184 * d - 112, 1816); } // History and stats update malus, based on depth -int stat_malus(Depth d) { return std::min(748 * d - 255, 1435); } +int stat_malus(Depth d) { return std::min(751 * d - 240, 1609); } // Add a small random component to draw evaluations to avoid 3-fold blindness Value value_draw(size_t nodes) { return VALUE_DRAW - 1 + Value(nodes & 0x2); } @@ -262,12 +262,12 @@ void Search::Worker::iterative_deepening() { // Reset aspiration window starting size Value avg = rootMoves[pvIdx].averageScore; - delta = 12 + avg * avg / 30272; + delta = 12 + avg * avg / 31464; alpha = std::max(avg - delta, -VALUE_INFINITE); beta = std::min(avg + delta, VALUE_INFINITE); // Adjust optimism based on root move's averageScore (~4 Elo) - optimism[us] = 95 * avg / (std::abs(avg) + 95); + optimism[us] = 98 * avg / (std::abs(avg) + 93); optimism[~us] = -optimism[us]; // Start with a small aspiration window and, in the case of a fail @@ -390,23 +390,23 @@ void Search::Worker::iterative_deepening() { { int nodesEffort = rootMoves[0].effort * 111 / std::max(size_t(1), size_t(nodes)); - double fallingEval = (73 + 18 * (mainThread->bestPreviousAverageScore - bestValue) + double fallingEval = (80 + 17 * (mainThread->bestPreviousAverageScore - bestValue) + 4 * (mainThread->iterValue[iterIdx] - bestValue)) - / 742.98; - fallingEval = std::clamp(fallingEval, 0.46, 1.60); + / 713.14; + fallingEval = std::clamp(fallingEval, 0.50, 1.51); // If the bestMove is stable over several iterations, reduce time accordingly - timeReduction = lastBestMoveDepth + 10 < completedDepth ? 1.85 : 0.64; - double reduction = (1.94 + mainThread->previousTimeReduction) / (2.43 * timeReduction); - double bestMoveInstability = 1.03 + 1.83 * totBestMoveChanges / threads.size(); - double recapture = limits.capSq == rootMoves[0].pv[0].to_sq() ? 1.026 : 0.931; + timeReduction = lastBestMoveDepth + 10 < completedDepth ? 2.03 : 0.68; + double reduction = (1.87 + mainThread->previousTimeReduction) / (2.52 * timeReduction); + double bestMoveInstability = 1.05 + 1.79 * totBestMoveChanges / threads.size(); + double recapture = limits.capSq == rootMoves[0].pv[0].to_sq() ? 0.965 : 0.948; double totalTime = mainThread->tm.optimum() * fallingEval * reduction * bestMoveInstability * recapture; auto elapsedTime = elapsed(); - if (completedDepth >= 10 && nodesEffort >= 89 && elapsedTime > totalTime * 0.80 + if (completedDepth >= 9 && nodesEffort >= 100 && elapsedTime > totalTime * 0.69 && !mainThread->ponder) threads.stop = true; @@ -421,7 +421,7 @@ void Search::Worker::iterative_deepening() { threads.stop = true; } else - threads.increaseDepth = mainThread->ponder || elapsedTime <= totalTime * 0.343; + threads.increaseDepth = mainThread->ponder || elapsedTime <= totalTime * 0.335; } mainThread->iterValue[iterIdx] = bestValue; @@ -437,8 +437,8 @@ void Search::Worker::iterative_deepening() { // Reset histories, usually before a new game void Search::Worker::clear() { mainHistory.fill(0); - captureHistory.fill(-700); - pawnHistory.fill(-1328); + captureHistory.fill(-723); + pawnHistory.fill(-1372); correctionHistory.fill(0); for (bool inCheck : {false, true}) @@ -448,7 +448,7 @@ void Search::Worker::clear() { h->fill(-72); for (size_t i = 1; i < reductions.size(); ++i) - reductions[i] = int((20.55 + std::log(size_t(options["Threads"])) / 2) * std::log(i)); + reductions[i] = int((19.14 + std::log(size_t(options["Threads"])) / 2) * std::log(i)); refreshTable.clear(network[numaAccessToken]); } @@ -639,7 +639,7 @@ Value Search::Worker::search( // Use static evaluation difference to improve quiet move ordering (~9 Elo) if (((ss - 1)->currentMove).is_ok() && !(ss - 1)->inCheck && !priorCapture) { - int bonus = std::clamp(-12 * int((ss - 1)->staticEval + ss->staticEval), -1003, 1820) + 800; + int bonus = std::clamp(-14 * int((ss - 1)->staticEval + ss->staticEval), -1099, 1860) + 633; thisThread->mainHistory[~us][((ss - 1)->currentMove).from_to()] << bonus; if (type_of(pos.piece_on(prevSq)) != PAWN) thisThread->pawnHistory[pawn_structure_index(pos)][pos.piece_on(prevSq)][prevSq] @@ -657,7 +657,7 @@ Value Search::Worker::search( // Step 6. Razoring (~1 Elo) // If eval is really low, check with qsearch if we can exceed alpha. If the // search suggests we cannot exceed alpha, return a speculative fail low. - if (eval < alpha - 1095 - 337 * depth * depth) + if (eval < alpha - 1092 - 327 * depth * depth) { value = qsearch(pos, ss, alpha - 1, alpha); if (value < alpha && std::abs(value) < VALUE_MATE_IN_MAX_PLY) @@ -666,24 +666,24 @@ Value Search::Worker::search( // Step 7. Futility pruning: child node (~40 Elo) // The depth condition is important for mate finding. - if (!ss->ttPv && depth < 9 + if (!ss->ttPv && depth < 10 && eval - futility_margin(depth, cutNode && !ss->ttHit, improving, opponentWorsening) - - (ss - 1)->statScore / 183 + - (ss - 1)->statScore / 188 >= beta && eval >= beta && (!ttData.move || ttCapture) && beta > VALUE_MATED_IN_MAX_PLY && eval < VALUE_MATE_IN_MAX_PLY) return beta + (eval - beta) / 3; // Step 8. Null move search with verification search (~35 Elo) - if (cutNode && (ss - 1)->currentMove != Move::null() && (ss - 1)->statScore < 12853 - && eval >= beta && ss->staticEval >= beta - 11 * depth + 129 && !excludedMove + if (cutNode && (ss - 1)->currentMove != Move::null() && (ss - 1)->statScore < 13085 + && eval >= beta && ss->staticEval >= beta - 11 * depth + 138 && !excludedMove && pos.major_material(us) && ss->ply >= thisThread->nmpMinPly && beta > VALUE_MATED_IN_MAX_PLY) { assert(eval - beta >= 0); // Null move dynamic reduction based on depth and eval - Depth R = std::min(int(eval - beta) / 143, 5) + depth / 3 + 5; + Depth R = std::min(int(eval - beta) / 158, 5) + depth / 3 + 5; ss->currentMove = Move::null(); ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0]; @@ -726,13 +726,13 @@ Value Search::Worker::search( // For cutNodes, if depth is high enough, decrease depth by 2 if there is no ttMove, // or by 1 if there is a ttMove with an upper bound. - if (cutNode && depth >= 9 && (!ttData.move || ttData.bound == BOUND_UPPER)) + if (cutNode && depth >= 8 && (!ttData.move || ttData.bound == BOUND_UPPER)) depth -= 1 + !ttData.move; // Step 10. ProbCut (~10 Elo) // If we have a good enough capture and a reduced search returns a value // much above beta, we can (almost) safely prune the previous move. - probCutBeta = beta + 146 - 67 * improving; + probCutBeta = beta + 152 - 71 * improving; if (!PvNode && depth > 4 && std::abs(beta) < VALUE_MATE_IN_MAX_PLY // If value from transposition table is lower than probCutBeta, don't attempt @@ -800,7 +800,7 @@ Value Search::Worker::search( moves_loop: // When in check, search starts here // Step 11. A small Probcut idea (~4 Elo) - probCutBeta = beta + 425; + probCutBeta = beta + 478; if ((ttData.bound & BOUND_LOWER) && ttData.depth >= depth - 3 && ttData.value >= probCutBeta && std::abs(beta) < VALUE_MATE_IN_MAX_PLY && std::abs(probCutBeta) < VALUE_MATE_IN_MAX_PLY) return probCutBeta; @@ -881,17 +881,17 @@ Value Search::Worker::search( thisThread->captureHistory[movedPiece][move.to_sq()][type_of(capturedPiece)]; // Futility pruning for captures (~2 Elo) - if (!givesCheck && lmrDepth < 16 && !ss->inCheck) + if (!givesCheck && lmrDepth < 17 && !ss->inCheck) { - Value futilityValue = ss->staticEval + 375 + 322 * lmrDepth + Value futilityValue = ss->staticEval + 404 + 294 * lmrDepth + PieceValue[capturedPiece] + captHist / 5; if (futilityValue <= alpha) continue; } // SEE based pruning for captures and checks (~11 Elo) - int seeHist = std::clamp(captHist / 35, -229 * depth, 163 * depth); - if (!pos.see_ge(move, -241 * depth - seeHist)) + int seeHist = std::clamp(captHist / 34, -211 * depth, 166 * depth); + if (!pos.see_ge(move, -270 * depth - seeHist)) continue; } else @@ -902,15 +902,15 @@ Value Search::Worker::search( + thisThread->pawnHistory[pawn_structure_index(pos)][movedPiece][move.to_sq()]; // Continuation history based pruning (~2 Elo) - if (history < -3653 * depth) + if (history < -3120 * depth) continue; history += 2 * thisThread->mainHistory[us][move.from_to()]; - lmrDepth += history / 4727; + lmrDepth += history / 4188; Value futilityValue = - ss->staticEval + (bestValue < ss->staticEval - 58 ? 136 : 119) + 138 * lmrDepth; + ss->staticEval + (bestValue < ss->staticEval - 57 ? 144 : 121) + 135 * lmrDepth; // Futility pruning: parent node (~13 Elo) if (!ss->inCheck && lmrDepth < 9 && futilityValue <= alpha) @@ -924,7 +924,7 @@ Value Search::Worker::search( lmrDepth = std::max(lmrDepth, 0); // Prune moves with negative SEE (~4 Elo) - if (!pos.see_ge(move, -28 * lmrDepth * lmrDepth)) + if (!pos.see_ge(move, -27 * lmrDepth * lmrDepth)) continue; } } @@ -951,7 +951,7 @@ Value Search::Worker::search( && std::abs(ttData.value) < VALUE_MATE_IN_MAX_PLY && (ttData.bound & BOUND_LOWER) && ttData.depth >= depth - 3) { - Value singularBeta = ttData.value - (46 + 56 * (ss->ttPv && !PvNode)) * depth / 81; + Value singularBeta = ttData.value - (43 + 57 * (ss->ttPv && !PvNode)) * depth / 71; Depth singularDepth = newDepth / 2; ss->excludedMove = move; @@ -961,13 +961,13 @@ Value Search::Worker::search( if (value < singularBeta) { - int doubleMargin = 313 * PvNode - 183 * !ttCapture; - int tripleMargin = 128 + 227 * PvNode - 293 * !ttCapture + 106 * ss->ttPv; + int doubleMargin = 272 * PvNode - 168 * !ttCapture; + int tripleMargin = 132 + 238 * PvNode - 303 * !ttCapture + 110 * ss->ttPv; extension = 1 + (value < singularBeta - doubleMargin) + (value < singularBeta - tripleMargin); - depth += ((!PvNode) && (depth < 16)); + depth += ((!PvNode) && (depth < 17)); } // Multi-cut pruning @@ -1000,7 +1000,7 @@ Value Search::Worker::search( else if (PvNode && move.to_sq() == prevSq && thisThread->captureHistory[movedPiece][move.to_sq()] [type_of(pos.piece_on(move.to_sq()))] - > 4306) + > 4528) extension = 1; } @@ -1056,10 +1056,10 @@ Value Search::Worker::search( ss->statScore = 2 * thisThread->mainHistory[us][move.from_to()] + (*contHist[0])[movedPiece][move.to_sq()] - + (*contHist[1])[movedPiece][move.to_sq()] - 5294; + + (*contHist[1])[movedPiece][move.to_sq()] - 4769; // Decrease/increase reduction for moves with a good/bad history (~8 Elo) - r -= ss->statScore / 9313; + r -= ss->statScore / 9242; // Step 16. Late moves reduction / extension (LMR, ~117 Elo) if (depth >= 2 && moveCount > 1 + (rootNode && depth < 10)) @@ -1078,7 +1078,7 @@ Value Search::Worker::search( { // Adjust full-depth search based on LMR results - if the result was // good enough search deeper, if it was bad enough search shallower. - const bool doDeeperSearch = value > (bestValue + 65 + 2 * newDepth); // (~1 Elo) + const bool doDeeperSearch = value > (bestValue + 67 + 2 * newDepth); // (~1 Elo) const bool doShallowerSearch = value < bestValue + newDepth; // (~2 Elo) newDepth += doDeeperSearch - doShallowerSearch; @@ -1202,7 +1202,7 @@ Value Search::Worker::search( else { // Reduce other moves if we have found at least one score improvement (~2 Elo) - if (depth > 2 && depth < 10 && std::abs(value) < VALUE_MATE_IN_MAX_PLY) + if (depth > 2 && depth < 11 && std::abs(value) < VALUE_MATE_IN_MAX_PLY) depth -= 2; assert(depth > 0); @@ -1246,23 +1246,23 @@ Value Search::Worker::search( else if (!priorCapture && prevSq != SQ_NONE) { int bonus = - (121 * (depth > 5) + 102 * (PvNode || cutNode) + 121 * ((ss - 1)->moveCount > 13) - + 61 * (!ss->inCheck && bestValue <= ss->staticEval - 138) - + 143 * (!(ss - 1)->inCheck && bestValue <= -(ss - 1)->staticEval - 81)); + (108 * (depth > 5) + 105 * (PvNode || cutNode) + 123 * ((ss - 1)->moveCount > 14) + + 64 * (!ss->inCheck && bestValue <= ss->staticEval - 133) + + 145 * (!(ss - 1)->inCheck && bestValue <= -(ss - 1)->staticEval - 75)); // proportional to "how much damage we have to undo" - bonus += std::clamp(-(ss - 1)->statScore / 100, -50, 250); + bonus += std::clamp(-(ss - 1)->statScore / 101, -56, 236); bonus = std::max(bonus, 0); update_continuation_histories(ss - 1, pos.piece_on(prevSq), prevSq, - stat_bonus(depth) * bonus / 106); + stat_bonus(depth) * bonus / 115); thisThread->mainHistory[~us][((ss - 1)->currentMove).from_to()] - << stat_bonus(depth) * bonus / 188; + << stat_bonus(depth) * bonus / 178; if (type_of(pos.piece_on(prevSq)) != PAWN) thisThread->pawnHistory[pawn_structure_index(pos)][pos.piece_on(prevSq)][prevSq] - << stat_bonus(depth) * bonus / 23; + << stat_bonus(depth) * bonus / 22; } if (PvNode) @@ -1431,7 +1431,7 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta, if (bestValue > alpha) alpha = bestValue; - futilityBase = ss->staticEval + 143; + futilityBase = ss->staticEval + 153; } const PieceToHistory* contHist[] = {(ss - 1)->continuationHistory, @@ -1501,11 +1501,11 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta, + (*contHist[1])[pos.moved_piece(move)][move.to_sq()] + thisThread->pawnHistory[pawn_structure_index(pos)][pos.moved_piece(move)] [move.to_sq()] - <= 3733) + <= 3682) continue; // Do not search moves with bad enough SEE values (~5 Elo) - if (!pos.see_ge(move, -105)) + if (!pos.see_ge(move, -110)) continue; } @@ -1571,7 +1571,7 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth Search::Worker::reduction(bool i, Depth d, int mn, int delta) const { int reductionScale = reductions[d] * reductions[mn]; - return (reductionScale + 2061 - delta * 1399 / rootDelta) / 1235 + (!i && reductionScale > 773); + return (reductionScale + 1863 - delta * 1516 / rootDelta) / 1312 + (!i && reductionScale > 701); } // elapsed() returns the time elapsed since the search started. If the