Someone lit a fire under the Stockfish team

[Vizvezdenec]

It's depth dependant SEE threshhold, basically some tweak of SEE pruning.

Aha, thanks Michael, then I understand a bit better the positive effect it has on Elo at longer time controls.

well, it will be more accurate with low depth pruning that uses SEE, I think it will help sf in tactics somewhat (although I'm not 100% sure).