- // Calculate new depth for this move
- newDepth = depth - ONE_PLY + extension;
-
- // Step 14. Pruning at shallow depth (~170 Elo)
- if ( !rootNode
- && pos.non_pawn_material(us)
- && bestValue > VALUE_MATED_IN_MAX_PLY)
- {
- // Skip quiet moves if movecount exceeds our FutilityMoveCount threshold
- moveCountPruning = moveCount >= futility_move_count(improving, depth / ONE_PLY);
-
- if ( !captureOrPromotion
- && !givesCheck
- && (!pos.advanced_pawn_push(move) || pos.non_pawn_material(~us) > BishopValueMg))
- {
- // Move count based pruning
- if (moveCountPruning)
- continue;
-
- // Reduced depth of the next LMR search
- int lmrDepth = std::max(newDepth - reduction(improving, depth, moveCount), DEPTH_ZERO);
- lmrDepth /= ONE_PLY;
-
- // Countermoves based pruning (~20 Elo)
- if ( lmrDepth < 4 + ((ss-1)->statScore > 0 || (ss-1)->moveCount == 1)
- && (*contHist[0])[movedPiece][to_sq(move)] < CounterMovePruneThreshold
- && (*contHist[1])[movedPiece][to_sq(move)] < CounterMovePruneThreshold)
- continue;
+ // Last captures extension
+ else if ( PieceValue[EG][pos.captured_piece()] > PawnValueEg
+ && pos.non_pawn_material() <= 2 * RookValueMg)
+ extension = 1;