Fractional plies and transposition tables

[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.

[bob]

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.

[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.

[brtzsnr]

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.