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Subject: Re: " Tb or not Tb?" Ay,That is the Question..

Author: Mike S.

Date: 02:52:14 02/06/06

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I recommend to make a compromise (don't bother to continue reading if you do not
accept compromises :-))

1. In GAMES*, do NOT use all giant tbs. you can get. I recommend a subset, all
3- and 4-piece tbs. and all KR?-KR (incl. KQR-KR) 5-piece tbs. Rook versus rook
endings are the most important in practice. So, you would get most of the
practical benefit and at the same time, escape from the slowdown effect which
would be caused by the other 5-piece tbs. you don't use then.

(Pure pawn endings are of course very important too, but easier to calculate in
conjunction with the 4-piece support.)

*) Analysis of late endgame positions is of course a different topic; I use
online ressources which offer up to 6-piece tbs. (which I do not have installed)
to check such positions.

In addition to all 70 3- and 4-piece tbs. files (~30 MB) these are the files

01.06.2001  01:00        14.061.624 kqrkr.nbw.emd
01.06.2001  01:00        28.475.167 kqrkr.nbb.emd
01.06.2001  05:00        11.267.500 krrkr.nbw.emd
01.06.2001  05:00        17.169.632 krrkr.nbb.emd
01.06.2001  05:00        16.970.339 krnkr.nbw.emd
01.06.2001  05:00         5.584.441 krnkr.nbb.emd
01.06.2001  05:00        17.189.887 krbkr.nbw.emd
01.06.2001  05:00         4.338.256 krbkr.nbb.emd
01.06.2001  06:00        68.946.403 krpkr.nbb.emd
01.06.2001  06:00        81.247.218 krpkr.nbw.emd

(~265 MB)

2. Use a larger tbs. cache. I recommend 32 MB. Some believe this is not
necessary and the Windows cache handles everything much better. Make your own
choice.

3. I assume that evals from tbs. hits are stored in the hash tables just like
any evals are. That would mean, large hash tables help to reduce the tbs.
slowdown effect too, again assuming that hash is always probed first no matter
if it is a tbs. position or not. (Of course, take care to not make them too
large, IOW avoid memory swapping.)

I'm not 100% sure about point (3.); maybe programmers can check if my
assumptions are correct?

Regards,
M.Scheidl



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