void Search::init() {
for (int i = 1; i < MAX_MOVES; ++i)
- Reductions[i] = int((22.0 + std::log(Threads.size())) * std::log(i));
+ Reductions[i] = int((22.0 + 2 * std::log(Threads.size())) * std::log(i + 0.25 * std::log(i)));
}
Time.init(Limits, us, rootPos.game_ply());
TT.new_search();
- Eval::verify_NNUE();
+ Eval::NNUE::verify();
if (rootMoves.empty())
{
++failedHighCnt;
}
else
- {
- ++rootMoves[pvIdx].bestMoveCount;
break;
- }
delta += delta / 4 + 5;
totBestMoveChanges += th->bestMoveChanges;
th->bestMoveChanges = 0;
}
- double bestMoveInstability = 1 + totBestMoveChanges / Threads.size();
+ double bestMoveInstability = 1 + 2 * totBestMoveChanges / Threads.size();
double totalTime = rootMoves.size() == 1 ? 0 :
Time.optimum() * fallingEval * reduction * bestMoveInstability;
Move ttMove, move, excludedMove, bestMove;
Depth extension, newDepth;
Value bestValue, value, ttValue, eval, maxValue, probCutBeta;
- bool ttHit, formerPv, givesCheck, improving, didLMR, priorCapture;
+ bool formerPv, givesCheck, improving, didLMR, priorCapture;
bool captureOrPromotion, doFullDepthSearch, moveCountPruning,
ttCapture, singularQuietLMR;
Piece movedPiece;
// starts with statScore = 0. Later grandchildren start with the last calculated
// statScore of the previous grandchild. This influences the reduction rules in
// LMR which are based on the statScore of parent position.
- if (rootNode)
- (ss+4)->statScore = 0;
- else
+ if (!rootNode)
(ss+2)->statScore = 0;
// Step 4. Transposition table lookup. We don't want the score of a partial
// position key in case of an excluded move.
excludedMove = ss->excludedMove;
posKey = excludedMove == MOVE_NONE ? pos.key() : pos.key() ^ make_key(excludedMove);
- tte = TT.probe(posKey, ttHit);
- ttValue = ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE;
+ tte = TT.probe(posKey, ss->ttHit);
+ ttValue = ss->ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE;
ttMove = rootNode ? thisThread->rootMoves[thisThread->pvIdx].pv[0]
- : ttHit ? tte->move() : MOVE_NONE;
+ : ss->ttHit ? tte->move() : MOVE_NONE;
if (!excludedMove)
- ss->ttPv = PvNode || (ttHit && tte->is_pv());
+ ss->ttPv = PvNode || (ss->ttHit && tte->is_pv());
formerPv = ss->ttPv && !PvNode;
if ( ss->ttPv
// thisThread->ttHitAverage can be used to approximate the running average of ttHit
thisThread->ttHitAverage = (TtHitAverageWindow - 1) * thisThread->ttHitAverage / TtHitAverageWindow
- + TtHitAverageResolution * ttHit;
+ + TtHitAverageResolution * ss->ttHit;
// At non-PV nodes we check for an early TT cutoff
if ( !PvNode
- && ttHit
+ && ss->ttHit
&& tte->depth() >= depth
&& ttValue != VALUE_NONE // Possible in case of TT access race
&& (ttValue >= beta ? (tte->bound() & BOUND_LOWER)
improving = false;
goto moves_loop;
}
- else if (ttHit)
+ else if (ss->ttHit)
{
// Never assume anything about values stored in TT
ss->staticEval = eval = tte->eval();
assert(eval - beta >= 0);
// Null move dynamic reduction based on depth and value
- Depth R = (817 + 71 * depth) / 213 + std::min(int(eval - beta) / 192, 3);
+ Depth R = (982 + 85 * depth) / 256 + std::min(int(eval - beta) / 192, 3);
ss->currentMove = MOVE_NULL;
ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0];
// there and in further interactions with transposition table cutoff depth is set to depth - 3
// because probCut search has depth set to depth - 4 but we also do a move before it
// so effective depth is equal to depth - 3
- && !( ttHit
+ && !( ss->ttHit
&& tte->depth() >= depth - 3
&& ttValue != VALUE_NONE
&& ttValue < probCutBeta))
{
// if ttMove is a capture and value from transposition table is good enough produce probCut
// cutoff without digging into actual probCut search
- if ( ttHit
+ if ( ss->ttHit
&& tte->depth() >= depth - 3
&& ttValue != VALUE_NONE
&& ttValue >= probCutBeta
if (value >= probCutBeta)
{
// if transposition table doesn't have equal or more deep info write probCut data into it
- if ( !(ttHit
+ if ( !(ss->ttHit
&& tte->depth() >= depth - 3
&& ttValue != VALUE_NONE))
tte->save(posKey, value_to_tt(value, ss->ply), ttPv,
&& captureHistory[movedPiece][to_sq(move)][type_of(pos.piece_on(to_sq(move)))] < 0)
continue;
- // Futility pruning for captures
- if ( !givesCheck
- && lmrDepth < 6
- && !(PvNode && abs(bestValue) < 2)
- && PieceValue[MG][type_of(movedPiece)] >= PieceValue[MG][type_of(pos.piece_on(to_sq(move)))]
- && !ss->inCheck
- && ss->staticEval + 169 + 244 * lmrDepth
- + PieceValue[MG][type_of(pos.piece_on(to_sq(move)))] <= alpha)
- continue;
-
// See based pruning
if (!pos.see_ge(move, Value(-221) * depth)) // (~25 Elo)
continue;
&& pos.non_pawn_material() <= 2 * RookValueMg)
extension = 1;
- // Castling extension
- if ( type_of(move) == CASTLING
- && popcount(pos.pieces(us) & ~pos.pieces(PAWN) & (to_sq(move) & KingSide ? KingSide : QueenSide)) <= 2)
- extension = 1;
-
// Late irreversible move extension
if ( move == ttMove
&& pos.rule50_count() > 80
// Step 16. Reduced depth search (LMR, ~200 Elo). If the move fails high it will be
// re-searched at full depth.
if ( depth >= 3
- && moveCount > 1 + 2 * rootNode + 2 * (PvNode && abs(bestValue) < 2)
+ && moveCount > 1 + 2 * rootNode
&& ( !captureOrPromotion
|| moveCountPruning
|| ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha
{
Depth r = reduction(improving, depth, moveCount);
- // Decrease reduction at non-check cut nodes for second move at low depths
- if ( cutNode
- && depth <= 10
- && moveCount <= 2
- && !ss->inCheck)
- r--;
-
// Decrease reduction if the ttHit running average is large
if (thisThread->ttHitAverage > 509 * TtHitAverageResolution * TtHitAverageWindow / 1024)
r--;
}
else
{
- // Increase reduction for captures/promotions if late move and at low depth
- if (depth < 8 && moveCount > 2)
- r++;
-
- // Unless giving check, this capture is likely bad
- if ( !givesCheck
- && ss->staticEval + PieceValue[EG][pos.captured_piece()] + 213 * depth <= alpha)
- r++;
+ // Increase reduction for captures/promotions if late move and at low depth
+ if (depth < 8 && moveCount > 2)
+ r++;
+
+ // Unless giving check, this capture is likely bad
+ if ( !givesCheck
+ && ss->staticEval + PieceValue[EG][pos.captured_piece()] + 213 * depth <= alpha)
+ r++;
}
Depth d = std::clamp(newDepth - r, 1, newDepth);
Move ttMove, move, bestMove;
Depth ttDepth;
Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha;
- bool ttHit, pvHit, givesCheck, captureOrPromotion;
+ bool pvHit, givesCheck, captureOrPromotion;
int moveCount;
if (PvNode)
: DEPTH_QS_NO_CHECKS;
// Transposition table lookup
posKey = pos.key();
- tte = TT.probe(posKey, ttHit);
- ttValue = ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE;
- ttMove = ttHit ? tte->move() : MOVE_NONE;
- pvHit = ttHit && tte->is_pv();
+ tte = TT.probe(posKey, ss->ttHit);
+ ttValue = ss->ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE;
+ ttMove = ss->ttHit ? tte->move() : MOVE_NONE;
+ pvHit = ss->ttHit && tte->is_pv();
if ( !PvNode
- && ttHit
+ && ss->ttHit
&& tte->depth() >= ttDepth
&& ttValue != VALUE_NONE // Only in case of TT access race
&& (ttValue >= beta ? (tte->bound() & BOUND_LOWER)
}
else
{
- if (ttHit)
+ if (ss->ttHit)
{
// Never assume anything about values stored in TT
if ((ss->staticEval = bestValue = tte->eval()) == VALUE_NONE)
// Stand pat. Return immediately if static value is at least beta
if (bestValue >= beta)
{
- if (!ttHit)
+ if (!ss->ttHit)
tte->save(posKey, value_to_tt(bestValue, ss->ply), false, BOUND_LOWER,
DEPTH_NONE, MOVE_NONE, ss->staticEval);
[pos.moved_piece(move)]
[to_sq(move)];
+ // CounterMove based pruning
if ( !captureOrPromotion
&& moveCount
&& (*contHist[0])[pos.moved_piece(move)][to_sq(move)] < CounterMovePruneThreshold
else
captureHistory[moved_piece][to_sq(bestMove)][captured] << bonus1;
- // Extra penalty for a quiet TT or main killer move in previous ply when it gets refuted
- if ( ((ss-1)->moveCount == 1 || ((ss-1)->currentMove == (ss-1)->killers[0]))
+ // Extra penalty for a quiet early move that was not a TT move or main killer move in previous ply when it gets refuted
+ if ( ((ss-1)->moveCount == 1 + (ss-1)->ttHit || ((ss-1)->currentMove == (ss-1)->killers[0]))
&& !pos.captured_piece())
update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -bonus1);
projects / stockfish / blobdiff