ext = ONE_PLY;
else if (givesCheck && pos.see_sign(move) >= 0)
- ext = PvNode ? ONE_PLY : ONE_PLY / 2;
+ ext = ONE_PLY / 2;
// Singular extension search. If all moves but one fail low on a search of
// (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move
// Step 19. Check for split
if ( !SpNode
&& depth >= Threads.min_split_depth()
+ && depth - reduction<PvNode>(depth, moveCount) >= Threads.min_split_depth()
&& bestValue < beta
&& Threads.available_slave_exists(thisThread)
&& !Signals.stop