// Futility pruning: parent node
if (predictedDepth < 7 * ONE_PLY)
{
- futilityValue = ss->staticEval + futility_margin(predictedDepth) + 256;
+ futilityValue = ss->staticEval + futility_margin(predictedDepth) + 256;
if (futilityValue <= alpha)
{
[pos.piece_on(to_sq(move))][to_sq(move)] <= VALUE_ZERO))
ss->reduction += ONE_PLY;
- if (move == countermove)
+ if ( move == countermove
+ || ( History[pos.piece_on(to_sq(move))][to_sq(move)] > VALUE_ZERO
+ && CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq]
+ [pos.piece_on(to_sq(move))][to_sq(move)] > VALUE_ZERO))
ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY);
// Decrease reduction for moves that escape a capture
value = -search<NonPV, false>(pos, ss+1, -(alpha+1), -alpha, d, true);
- // Re-search at intermediate depth if reduction is very high
- if (value > alpha && ss->reduction >= 4 * ONE_PLY)
- {
- Depth d2 = std::max(newDepth - 2 * ONE_PLY, ONE_PLY);
- value = -search<NonPV, false>(pos, ss+1, -(alpha+1), -alpha, d2, true);
- }
-
doFullDepthSearch = (value > alpha && ss->reduction != DEPTH_ZERO);
ss->reduction = DEPTH_ZERO;
}
}
// Extra penalty for TT move in previous ply when it gets refuted
- if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove)
+ if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove && !pos.captured_piece_type())
{
Square prevPrevSq = to_sq((ss-2)->currentMove);
HistoryStats& ttMoveCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];