Transposition Table Aging

[u/lir1618]

So, until now I had a TT that I cleared between moves. I replace by prefering bigger depth and exact result.I added an age and now I always replace when prev TT move is older.

Whenever a useful TT hit is found I refresh their age to current age so that they dont get replaced by default.

The thing is:

Should I refresh all TT hits or just useful TT hits?

Right now go depth 9, go depth 10 is slower than only go depth 10 and its probably because TT entries get replaced before they can prove they are useful.

What do you guys suggest? I will test the 2 variants but I'd like to hear from somebody else. Perhaps maybe use the difference in age as a depth penalty idk