&& ttMove == MOVE_NONE
&& (PvNode || (!inCheck && ss->staticEval + Value(256) >= beta)))
{
- Depth d = (PvNode ? depth - 2 * ONE_PLY : depth / 2);
+ Depth d = (PvNode ? depth - 2 * ONE_PLY : depth - 4 * ONE_PLY);
ss->skipNullMove = true;
search<PvNode ? PV : NonPV>(pos, ss, alpha, beta, d);