Hashing 50 Move Counter

[brianr]

The copy/make thread made me wonder about also hashing the 50 move counter.
I assume most already hash castle and ep status.

Does anyone bother also hashing the 50 move counter too?

Thanks,
Brian

[rjgibert]

Wouldn't you miss a lot of useful transpositions if you hash the 50 move counter?

[hgm]

Hashing the 50-move counter would make hashing almost useless. It is usually better to ignore the 50-move counter anyway, so it is not clear for what you would pay this price.

[bob]

The copy/make thread made me wonder about also hashing the 50 move counter.
I assume most already hash castle and ep status.

Does anyone bother also hashing the 50 move counter too?

Thanks,
Brian

No, it would absolutely kill your hash hit rate, because you essentially change the "if (draft >= depth)" test that determines if the hash entry is usable to "if (draft == depth)" which is not what you want.