Killer moves in Quiesce

[edwardyu]

I wonder why engines seldom use killer moves in Quiesce search. At least they may save generation of captures or checking moves or check evasions.

[Sven]

I wonder why engines seldom use killer moves in Quiesce search. At least they may save generation of captures or checking moves or check evasions.

The reason is quite simple: most engines do not store captures/promotions as killer moves, and since quiescence search usually is restricted to captures/promotions only, there is no need for killer moves within the quiescence search.

A common principle of move ordering within the full width search prefers captures (at least those that do not seem to lose material, sometimes even all captures) over killer moves, which might explain the relation between these two groups.

Sven