Search instability or ?...

[Daniel Anulliero]

Yesterday I was horrified (lol) to see Isa not playing always the same moves from time to time in some games vs the same oponent, same openning and same TC.
Is this the famous search instability or others things ,like bugs in TT or ?
What do you think?

[brtzsnr]

same TC.

There is your problem. Even at same TC there is a lot of non-determinism, for example a job running in the background. Try playing at fixed depth an see if it's still an issue.

One problem I found recently in my engine was that TT was updated during search shutdown which was wrong because the search is incomplete.

[Daniel Anulliero]

same TC.

There is your problem. Even at same TC there is a lot of non-determinism, for example a job running in the background. Try playing at fixed depth an see if it's still an issue.

One problem I found recently in my engine was that TT was updated during search shutdown which was wrong because the search is incomplete.

Ok thanks alexandru, didn't think about this possibility
That's why we need more than one PC for testing lol
Dany