From ededadcd6f7fbb9eb122f5fe336025cc4b11753b Mon Sep 17 00:00:00 2001 From: Muzhen Gaming <61100393+XInTheDark@users.noreply.github.com> Date: Thu, 1 Feb 2024 08:13:06 +0800 Subject: [PATCH] VVLTC search tune Search parameters were tuned at 60+0.6 8-thread. Link to the tuning attempt: https://tests.stockfishchess.org/tests/view/65b84e8dc865510db0276030 The most significant change is the triple extension parameter, from 200 to 78. This presumably improves scaling. Additionally, the value < singularBeta - 2 condition for double extensions was removed. This can simply be considered a parameter tweak from 2 to 0. Passed VVLTC: https://tests.stockfishchess.org/tests/view/65baec69c865510db0278f19 LLR: 2.94 (-2.94,2.94) <0.00,2.00> Total: 26136 W: 6564 L: 6305 D: 13267 Ptnml(0-2): 2, 2413, 7977, 2676, 0 Passed VVLTC vs passed PR #5027: https://tests.stockfishchess.org/tests/view/65bc2adfc865510db027a561 LLR: 2.95 (-2.94,2.94) <0.50,2.50> Total: 52968 W: 13372 L: 13046 D: 26550 Ptnml(0-2): 4, 4944, 16265, 5264, 7 STC Elo estimate: https://tests.stockfishchess.org/tests/view/65be5514c865510db027cbc5 closes https://github.com/official-stockfish/Stockfish/pull/5029 Bench: 1478189 --- src/search.cpp | 74 +++++++++++++++++++++++++------------------------- 1 file changed, 37 insertions(+), 37 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index 538f0f30ae2..e57f2557cf8 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -55,7 +55,7 @@ namespace { // Futility margin Value futility_margin(Depth d, bool noTtCutNode, bool improving) { - Value futilityMult = 114 - 47 * noTtCutNode; + Value futilityMult = 116 - 47 * noTtCutNode; return (futilityMult * d - 3 * futilityMult / 2 * improving); } @@ -66,15 +66,15 @@ constexpr int futility_move_count(bool improving, Depth depth) { // Add correctionHistory value to raw staticEval and guarantee evaluation does not hit the tablebase range Value to_corrected_static_eval(Value v, const Worker& w, const Position& pos) { auto cv = w.correctionHistory[pos.side_to_move()][pawn_structure_index(pos)]; - v += cv * std::abs(cv) / 14095; + v += cv * std::abs(cv) / 12890; return std::clamp(int(v), VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1); } // History and stats update bonus, based on depth -int stat_bonus(Depth d) { return std::min(265 * d - 349, 1112); } +int stat_bonus(Depth d) { return std::min(253 * d - 356, 1117); } // History and stats update malus, based on depth -int stat_malus(Depth d) { return std::min(482 * d - 326, 1172); } +int stat_malus(Depth d) { return std::min(517 * d - 308, 1206); } // 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); } @@ -297,12 +297,12 @@ void Search::Worker::iterative_deepening() { // Reset aspiration window starting size Value avg = rootMoves[pvIdx].averageScore; - delta = Value(9) + int(avg) * avg / 13181; + delta = Value(9) + int(avg) * avg / 12480; alpha = std::max(avg - delta, -VALUE_INFINITE); beta = std::min(avg + delta, int(VALUE_INFINITE)); // Adjust optimism based on root move's averageScore (~4 Elo) - optimism[us] = 132 * avg / (std::abs(avg) + 98); + optimism[us] = 131 * avg / (std::abs(avg) + 95); optimism[~us] = -optimism[us]; // Start with a small aspiration window and, in the case of a fail @@ -726,7 +726,7 @@ 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(-13 * int((ss - 1)->staticEval + ss->staticEval), -1680, 1406); + int bonus = std::clamp(-14 * int((ss - 1)->staticEval + ss->staticEval), -1661, 1495); bonus = bonus > 0 ? 2 * bonus : bonus / 2; thisThread->mainHistory[~us][((ss - 1)->currentMove).from_to()] << bonus; if (type_of(pos.piece_on(prevSq)) != PAWN && ((ss - 1)->currentMove).type_of() != PROMOTION) @@ -747,7 +747,7 @@ Value Search::Worker::search( // If eval is really low check with qsearch if it can exceed alpha, if it can't, // return a fail low. // Adjust razor margin according to cutoffCnt. (~1 Elo) - if (eval < alpha - 435 - (327 - 167 * ((ss + 1)->cutoffCnt > 3)) * depth * depth) + if (eval < alpha - 450 - (332 - 160 * ((ss + 1)->cutoffCnt > 3)) * depth * depth) { value = qsearch(pos, ss, alpha - 1, alpha); if (value < alpha) @@ -760,20 +760,20 @@ Value Search::Worker::search( && eval - futility_margin(depth, cutNode && !ss->ttHit, improving) - (ss - 1)->statScore / 327 >= beta - && eval >= beta && eval < 27734 // smaller than TB wins + && eval >= beta && eval < 28702 // smaller than TB wins && (!ttMove || ttCapture)) return beta > VALUE_TB_LOSS_IN_MAX_PLY ? (eval + beta) / 2 : eval; // Step 9. Null move search with verification search (~35 Elo) - if (!PvNode && (ss - 1)->currentMove != Move::null() && (ss - 1)->statScore < 17787 - && eval >= beta && eval >= ss->staticEval && ss->staticEval >= beta - 22 * depth + 313 + if (!PvNode && (ss - 1)->currentMove != Move::null() && (ss - 1)->statScore < 17379 + && eval >= beta && eval >= ss->staticEval && ss->staticEval >= beta - 21 * depth + 329 && !excludedMove && pos.non_pawn_material(us) && ss->ply >= thisThread->nmpMinPly && beta > VALUE_TB_LOSS_IN_MAX_PLY) { assert(eval - beta >= 0); // Null move dynamic reduction based on depth and eval - Depth R = std::min(int(eval - beta) / 144, 6) + depth / 3 + 4; + Depth R = std::min(int(eval - beta) / 148, 6) + depth / 3 + 4; ss->currentMove = Move::null(); ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0]; @@ -787,7 +787,7 @@ Value Search::Worker::search( // Do not return unproven mate or TB scores if (nullValue >= beta && nullValue < VALUE_TB_WIN_IN_MAX_PLY) { - if (thisThread->nmpMinPly || depth < 15) + if (thisThread->nmpMinPly || depth < 16) return nullValue; assert(!thisThread->nmpMinPly); // Recursive verification is not allowed @@ -820,7 +820,7 @@ Value Search::Worker::search( if (cutNode && depth >= 8 && !ttMove) depth -= 2; - probCutBeta = beta + 173 - 73 * improving; + probCutBeta = beta + 182 - 68 * improving; // Step 11. ProbCut (~10 Elo) // If we have a good enough capture (or queen promotion) and a reduced search returns a value @@ -880,7 +880,7 @@ Value Search::Worker::search( moves_loop: // When in check, search starts here // Step 12. A small Probcut idea, when we are in check (~4 Elo) - probCutBeta = beta + 427; + probCutBeta = beta + 446; if (ss->inCheck && !PvNode && ttCapture && (tte->bound() & BOUND_LOWER) && tte->depth() >= depth - 4 && ttValue >= probCutBeta && std::abs(ttValue) < VALUE_TB_WIN_IN_MAX_PLY && std::abs(beta) < VALUE_TB_WIN_IN_MAX_PLY) @@ -963,7 +963,7 @@ Value Search::Worker::search( { Piece capturedPiece = pos.piece_on(move.to_sq()); int futilityEval = - ss->staticEval + 277 + 298 * lmrDepth + PieceValue[capturedPiece] + ss->staticEval + 279 + 295 * lmrDepth + PieceValue[capturedPiece] + thisThread->captureHistory[movedPiece][move.to_sq()][type_of(capturedPiece)] / 7; if (futilityEval < alpha) @@ -971,7 +971,7 @@ Value Search::Worker::search( } // SEE based pruning for captures and checks (~11 Elo) - if (!pos.see_ge(move, -203 * depth)) + if (!pos.see_ge(move, -204 * depth)) continue; } else @@ -983,17 +983,17 @@ Value Search::Worker::search( + thisThread->pawnHistory[pawn_structure_index(pos)][movedPiece][move.to_sq()]; // Continuation history based pruning (~2 Elo) - if (lmrDepth < 6 && history < -4195 * depth) + if (lmrDepth < 6 && history < -4215 * depth) continue; history += 2 * thisThread->mainHistory[us][move.from_to()]; - lmrDepth += history / 6992; + lmrDepth += history / 6658; // Futility pruning: parent node (~13 Elo) if (!ss->inCheck && lmrDepth < 15 - && ss->staticEval + (bestValue < ss->staticEval - 63 ? 137 : 64) - + 111 * lmrDepth + && ss->staticEval + (bestValue < ss->staticEval - 58 ? 139 : 55) + + 121 * lmrDepth <= alpha) continue; @@ -1020,11 +1020,11 @@ Value Search::Worker::search( // so changing them requires tests at these types of time controls. // Recursive singular search is avoided. if (!rootNode && move == ttMove && !excludedMove - && depth >= 4 - (thisThread->completedDepth > 31) + ss->ttPv + && depth >= 4 - (thisThread->completedDepth > 29) + ss->ttPv && std::abs(ttValue) < VALUE_TB_WIN_IN_MAX_PLY && (tte->bound() & BOUND_LOWER) && tte->depth() >= depth - 3) { - Value singularBeta = ttValue - (58 + 52 * (ss->ttPv && !PvNode)) * depth / 64; + Value singularBeta = ttValue - (62 + 52 * (ss->ttPv && !PvNode)) * depth / 64; Depth singularDepth = newDepth / 2; ss->excludedMove = move; @@ -1037,10 +1037,10 @@ Value Search::Worker::search( extension = 1; // Avoid search explosion by limiting the number of double extensions - if (!PvNode && value < singularBeta - 2 && ss->doubleExtensions <= 15) + if (!PvNode && ss->doubleExtensions <= 16) { - extension = 2 + (value < singularBeta - 200 && !ttCapture); - depth += depth < 15; + extension = 2 + (value < singularBeta - 78 && !ttCapture); + depth += depth < 16; } } @@ -1077,14 +1077,14 @@ Value Search::Worker::search( // Quiet ttMove extensions (~1 Elo) else if (PvNode && move == ttMove && move == ss->killers[0] - && (*contHist[0])[movedPiece][move.to_sq()] >= 4111) + && (*contHist[0])[movedPiece][move.to_sq()] >= 4339) extension = 1; // Recapture extensions (~1 Elo) else if (PvNode && move == ttMove && move.to_sq() == prevSq && thisThread->captureHistory[movedPiece][move.to_sq()] [type_of(pos.piece_on(move.to_sq()))] - > 4484) + > 4356) extension = 1; } @@ -1140,10 +1140,10 @@ 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()] - + (*contHist[3])[movedPiece][move.to_sq()] - 4119; + + (*contHist[3])[movedPiece][move.to_sq()] - 4409; // Decrease/increase reduction for moves with a good/bad history (~25 Elo) - r -= ss->statScore / 15373; + r -= ss->statScore / 14894; // Step 17. Late moves reduction / extension (LMR, ~117 Elo) if (depth >= 2 && moveCount > 1 + rootNode) @@ -1162,7 +1162,7 @@ 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 + 51 + 2 * newDepth); // (~1 Elo) + const bool doDeeperSearch = value > (bestValue + 49 + 2 * newDepth); // (~1 Elo) const bool doShallowerSearch = value < bestValue + newDepth; // (~2 Elo) newDepth += doDeeperSearch - doShallowerSearch; @@ -1278,7 +1278,7 @@ Value Search::Worker::search( else { // Reduce other moves if we have found at least one score improvement (~2 Elo) - if (depth > 2 && depth < 12 && beta < 13195 && value > -12346) + if (depth > 2 && depth < 13 && beta < 13710 && value > -12589) depth -= 2; assert(depth > 0); @@ -1317,8 +1317,8 @@ Value Search::Worker::search( // Bonus for prior countermove that caused the fail low else if (!priorCapture && prevSq != SQ_NONE) { - int bonus = (depth > 5) + (PvNode || cutNode) + ((ss - 1)->statScore < -16797) - + ((ss - 1)->moveCount > 10); + int bonus = (depth > 5) + (PvNode || cutNode) + ((ss - 1)->statScore < -15401) + + ((ss - 1)->moveCount > 11); update_continuation_histories(ss - 1, pos.piece_on(prevSq), prevSq, stat_bonus(depth) * bonus); thisThread->mainHistory[~us][((ss - 1)->currentMove).from_to()] @@ -1476,7 +1476,7 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta, if (bestValue > alpha) alpha = bestValue; - futilityBase = ss->staticEval + 186; + futilityBase = ss->staticEval + 204; } const PieceToHistory* contHist[] = {(ss - 1)->continuationHistory, @@ -1556,7 +1556,7 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta, continue; // Do not search moves with bad enough SEE values (~5 Elo) - if (!pos.see_ge(move, -76)) + if (!pos.see_ge(move, -75)) continue; } @@ -1711,7 +1711,7 @@ void update_all_stats(const Position& pos, if (!pos.capture_stage(bestMove)) { - int bestMoveBonus = bestValue > beta + 177 ? quietMoveBonus // larger bonus + int bestMoveBonus = bestValue > beta + 167 ? quietMoveBonus // larger bonus : stat_bonus(depth); // smaller bonus // Increase stats for the best move in case it was a quiet move