- ext = extension(pos, move, true, captureOrPromotion, moveIsCheck, singleReply, mateThreat, &dangerous);
-
- // We want to extend the TT move if it is much better then remaining ones.
- // To verify this we do a reduced search on all the other moves but the ttMove,
- // if result is lower then TT value minus a margin then we assume ttMove is the
- // only one playable. It is a kind of relaxed single reply extension.
- // Note that could be ttMove != tte->move() due to IID, so we always use tte->move()
- // to avoid aliases when we probe tte->depth() and tte->type()
- if ( depth >= 8 * OnePly
+ ext = extension(pos, move, true, captureOrPromotion, moveIsCheck, singleEvasion, mateThreat, &dangerous);
+
+ // Singular extension search. We extend the TT move if its value is much better than
+ // its siblings. To verify this we do a reduced search on all the other moves but the
+ // ttMove, if result is lower then ttValue minus a margin then we extend ttMove.
+ if ( depth >= 6 * OnePly