Extend for an extra half-ply in case the node is (probably)
going to fail high. In this case the added overhead is limited.
A novelity is the way this patch has been tested: Always in
self-play but with a much longer TC to allow the singular
extension to fully kick in and also (my impression) to have
less noisy results.
Ater 1015 games on my QUAD at 60"+0.05
Mod vs Orig 173 - 150 - 692 ELO +8
ss->excludedMove = MOVE_NONE;
if (value < rBeta)
- ext = ONE_PLY;
+ ext = rBeta >= beta ? ONE_PLY + ONE_PLY / 2 : ONE_PLY;
}
// Update current move (this must be done after singular extension search)