TTEntry* tte;
Key posKey;
Move ttMove, move, excludedMove, bestMove;
- Depth extension, newDepth, predictedDepth;
+ Depth extension, newDepth;
Value bestValue, value, ttValue, eval, nullValue;
bool ttHit, inCheck, givesCheck, singularExtensionNode, improving;
bool captureOrPromotion, doFullDepthSearch, moveCountPruning;
}
// Extra penalty for a quiet TT move in previous ply when it gets refuted
- if ((ss-1)->moveCount == 1 && !pos.captured_piece_type())
+ if ((ss-1)->moveCount == 1 && !pos.captured_piece())
{
Value penalty = Value(d * d + 4 * d + 1);
Square prevSq = to_sq((ss-1)->currentMove);
newDepth = depth - ONE_PLY + extension;
// Step 13. Pruning at shallow depth
- if ( !rootNode
- && !captureOrPromotion
- && !inCheck
- && !givesCheck
- && bestValue > VALUE_MATED_IN_MAX_PLY
- && !pos.advanced_pawn_push(move))
+ if ( !rootNode
+ && !inCheck
+ && bestValue > VALUE_MATED_IN_MAX_PLY)
{
- // Move count based pruning
- if (moveCountPruning)
- continue;
-
- predictedDepth = std::max(newDepth - reduction<PvNode>(improving, depth, moveCount), DEPTH_ZERO);
+ if ( !captureOrPromotion
+ && !givesCheck
+ && !pos.advanced_pawn_push(move))
+ {
+ // Move count based pruning
+ if (moveCountPruning)
+ continue;
- // Countermoves based pruning
- if ( predictedDepth < 3 * ONE_PLY
- && (!cmh || (*cmh )[moved_piece][to_sq(move)] < VALUE_ZERO)
- && (!fmh || (*fmh )[moved_piece][to_sq(move)] < VALUE_ZERO)
- && (!fmh2 || (*fmh2)[moved_piece][to_sq(move)] < VALUE_ZERO || (cmh && fmh)))
- continue;
+ // Reduced depth of the next LMR search
+ int lmrDepth = std::max(newDepth - reduction<PvNode>(improving, depth, moveCount), DEPTH_ZERO) / ONE_PLY;
- // Futility pruning: parent node
- if ( predictedDepth < 7 * ONE_PLY
- && ss->staticEval + 256 + 200 * predictedDepth / ONE_PLY <= alpha)
- continue;
+ // Countermoves based pruning
+ if ( lmrDepth < 3
+ && (!cmh || (*cmh )[moved_piece][to_sq(move)] < VALUE_ZERO)
+ && (!fmh || (*fmh )[moved_piece][to_sq(move)] < VALUE_ZERO)
+ && (!fmh2 || (*fmh2)[moved_piece][to_sq(move)] < VALUE_ZERO || (cmh && fmh)))
+ continue;
- // Prune moves with negative SEE at low depths and below a decreasing
- // threshold at higher depths.
- if (predictedDepth < 8 * ONE_PLY)
- {
- Value see_v = predictedDepth < 4 * ONE_PLY ? VALUE_ZERO
- : -PawnValueMg * 2 * int(predictedDepth - 3 * ONE_PLY) / ONE_PLY;
+ // Futility pruning: parent node
+ if ( lmrDepth < 7
+ && ss->staticEval + 256 + 200 * lmrDepth <= alpha)
+ continue;
- if (pos.see_sign(move) < see_v)
+ // Prune moves with negative SEE
+ if ( lmrDepth < 8
+ && pos.see_sign(move) < Value(-35 * lmrDepth * lmrDepth))
continue;
}
+ else if ( depth < 7 * ONE_PLY
+ && pos.see_sign(move) < Value(-35 * depth / ONE_PLY * depth / ONE_PLY))
+ continue;
}
// Speculative prefetch as early as possible
}
// Extra penalty for a quiet TT move in previous ply when it gets refuted
- if ((ss-1)->moveCount == 1 && !pos.captured_piece_type())
+ if ((ss-1)->moveCount == 1 && !pos.captured_piece())
{
Value penalty = Value(d * d + 4 * d + 1);
Square prevSq = to_sq((ss-1)->currentMove);
}
// Bonus for prior countermove that caused the fail low
else if ( depth >= 3 * ONE_PLY
- && !pos.captured_piece_type()
+ && !pos.captured_piece()
&& is_ok((ss-1)->currentMove))
{
int d = depth / ONE_PLY;
RootInTB = root_probe_wdl(pos, rootMoves, TB::Score);
// Only probe during search if winning
- if (TB::Score <= VALUE_DRAW)
+ if (RootInTB && TB::Score <= VALUE_DRAW)
Cardinality = 0;
}