Hi Duncan,duncan wrote: I compared results of Stockfish_x32_modern_170724_savehash: with Stockfish-TCEC6-32-PA_GTB:

the following position I suspect is a mate in 10. Stockfish_x32_modern_170724_savehash found a mate in 14 in 2 and half minutes on my computer depth 23. while Stockfish-TCEC6-32-PA_GTB takes over 9 minutes depth depth 25 to find a mate in 23.

so it seems for finding mates, latest stockfish is much faster. so it makes your work all the more valuable

thanks for doing this . much appreciated .

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I'll run a test like this, to check if PHs will retain valuable entries: I'll set a complicated position up, then I'll try, in infinite move, to make moves, variations, to take them back, to try another variation, to take its moves back, watching if score gets propagated and if engine "remembers" scores of each variation (with an approx, as having the main hash persistent can't be as precise as a dedicated separate hash). Then, one could test saving and reloading that hash to check, again, if the engine kept all scores.

To test all above with different hash sizes will give us an idea of the min hash amount needed for long time analysis. If you analyze 1000 positions wiwh 4 GB hash each you'd need a 4 TBs HD.... So the lower the reliable size, the better the system.

I'll run a similar test on next sunday. It'd be nice if you do something similar so we can compare results.

Rodolfo