In evaluate_unstoppable_pawns(...) within the first while loop you do not check for enemy pieces blocking a square in front of a passed pawn. In that case you should "give up" on that pawn. There might be more to fix or make better in that function. Passed pawn detection is very ELO critical. So it ...

i.e. If your testing techniques are superior, and perhaps empirical....then why is StockFish not as strong than the rest of the field?

Because we are not able to come up with winning ideas: we test a lot, but for the most part candidate changes result in no ELO change or even in a weaker engine ...

Thanks Marco, did you see the behavior report at this post?

http://www.open-chess.org/viewtopic.php?f=5&t=1042&start=184

One would like Stockfish to behave like in the bottom (Stockfish_201_PA_GTBf.7z) instead like in the top (back-ported code), the time saved does accumulate and has an impact on ...

What's the Elo gain on probing at PV nodes with your first given version vs SF default?

After 5811 games Mod- Orig: 1037 - 902 - 3872 +8 ELO (+- 3.6) LOS 97%

Ok thanks. I will retest my modification against SF default, TC 20''+0.1, 4 threads.
Or did you use other TC/threads usage parameters for ...

I would be happy if fruity's improvements were used on the official Stockfish, since they don't seem to hurt and they make analysis (where unlike games, it's important to revisit positions and transpositions over and over) better.

Using of TT also in PV nodes will be used on the official ...

Final result: +13169 -12852 =33979 (+2 Elo)

What do you test at 20''? Your most recently given code against the code which probes in search() but not in qsearch()?
How many threads per engine do you use?

Another intermediate result from my test at 10'' after 31,465 games: +6952 -6689 =17824 (+3 Elo)
I use 1 thread per engine and let play 6 ...

Your code is not exactly functionally equivalent with mine, because in PV case I accept all mate(d) values, not only those outside the alpha-beta window. Please have a look again.


Yes I noticed, in case current patch does not work I will retest with your original version.

BTW after 3250 games ...

I try to confirm the result with 60000 10'' games now.
:idea: My electricity provider will be glad :idea:

Ok. Let's do electricity providers happy. I'm going to add in test queue this one:


Subject: Use TT in PV also in qsearch()

Patch from Fruity:

http://www.open-chess.org/viewtopic.php?f=5 ...

Sorry for posting only now, but I have limited net access these days.

Thanks for sharing your results. The most interesting thing is that 2 secs of TC seem to hold and give a realistic result. I would have tested 10K at 10 secs, but more for my prejudicies than for a real reason.

Your patch ...