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Fractional plies and transposition tables

Posted: Sat Apr 18, 2015 2:30 pm
by brtzsnr
Which depth should I store in the transposition table?

1) Remaining fractional depth
2) Remaining plies left (excluding extension)?

I use the second and I remember trying the first option. However it doesn't seem natural to me that I need to track both ply and fractional depth.

Re: Fractional plies and transposition tables

Posted: Sat Apr 18, 2015 3:30 pm
by bob
brtzsnr wrote:Which depth should I store in the transposition table?

1) Remaining fractional depth
2) Remaining plies left (excluding extension)?

I use the second and I remember trying the first option. However it doesn't seem natural to me that I need to track both ply and fractional depth.
Has to be the remaining depth, how ever you use it. Otherwise you can never get an accurate comparison when you ask "is the draft sufficient?" When I did fractional plies I stored fractional plies. It's the only thing that makes sense.

Re: Fractional plies and transposition tables

Posted: Sun Apr 19, 2015 8:25 am
by hgm
As Bob says, the only purpose of this item is to judge if the stored data is good enough to satisfy the probe request. That means it should also encode differences between PV searches and cut-node or all-node searches, if your engine prunes those differently.

Re: Fractional plies and transposition tables

Posted: Mon Apr 20, 2015 9:52 pm
by brtzsnr
bob wrote: Has to be the remaining depth, how ever you use it. Otherwise you can never get an accurate comparison when you ask "is the draft sufficient?" When I did fractional plies I stored fractional plies. It's the only thing that makes sense.
Thanks. Tried fractional depth and it gave a 6ELO increase. I wonder why it failed the first time I tried.