Stockfish 7 and partial 6 piece syzygy problem?

[Modern Times]

If I were Ronald, I would probably just fix the initialization code so that it would not try to use any 6 piece files unless ALL 6 piece files are available, then this kind of problem goes away.

I agree, I think that is a sensible approach.

[syzygy]

I see there has been syzygy rewriting lately. May be this can be fixed at the same time?

The SF rewrite will only slow down the probing code with no benefit (I've already shown how to do the rewrite properly, but there is no interest).

However, I have just fixed it here, because it is a bug to do anything with TBScore if the probe was not successful:
https://github.com/syzygy1/Cfish/blob/e ... rch.c#L886

Even if this were fixed in SF, I make no guarantee that probing an incomplete set of tables does what you would like it to do.

[mcostalba]

I see there has been syzygy rewriting lately. May be this can be fixed at the same time?

The SF rewrite will only slow down the probing code with no benefit (I've already shown how to do the rewrite properly, but there is no interest).

However, I have just fixed it here, because it is a bug to do anything with TBScore if the probe was not successful:
https://github.com/syzygy1/Cfish/blob/e ... rch.c#L886

Even if this were fixed in SF, I make no guarantee that probing an incomplete set of tables does what you would like it to do.

Thanks to all people involved, for reporting the bug, finding the fix and confirming the bug.

I will open a PR and fix SF, possibly this week end.

[mcostalba]

Bug has been fixed now.

[Jouni]

Seems to work now OK without any obvious drawback!