YBW engines past and present?

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IanKennedy
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YBW engines past and present?

Post by IanKennedy » Wed Dec 30, 2020 10:26 am

Stockfish 6 used YBW and ditched it in favour of lazy SMP for SF7. I downloaded it the other day to see how it looks and was wondering what other available engines/builds there are that use it? Doesn't have to be a recent version as long as it builds and runs ok.
Author of the actively developed PSYCHO chess engine

mar
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Full name: Martin Sedlak

Re: YBW engines past and present?

Post by mar » Wed Dec 30, 2020 4:38 pm

IanKennedy wrote:
Wed Dec 30, 2020 10:26 am
Stockfish 6 used YBW and ditched it in favour of lazy SMP for SF7. I downloaded it the other day to see how it looks and was wondering what other available engines/builds there are that use it? Doesn't have to be a recent version as long as it builds and runs ok.
Crafty, Scorpio and Dirty come to mind (unless I'm mistaken and something has changed), I'm pretty sure there's more that I forgot.
Martin Sedlak

IanKennedy
Posts: 46
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Location: UK

Re: YBW engines past and present?

Post by IanKennedy » Wed Dec 30, 2020 6:30 pm

mar wrote:
Wed Dec 30, 2020 4:38 pm
IanKennedy wrote:
Wed Dec 30, 2020 10:26 am
Stockfish 6 used YBW and ditched it in favour of lazy SMP for SF7. I downloaded it the other day to see how it looks and was wondering what other available engines/builds there are that use it? Doesn't have to be a recent version as long as it builds and runs ok.
Crafty, Scorpio and Dirty come to mind (unless I'm mistaken and something has changed), I'm pretty sure there's more that I forgot.
I thought I read in the archives that Crafty used something of its own called DTS? (Distributed Tree Search).
Author of the actively developed PSYCHO chess engine

mar
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Location: Czech Republic
Full name: Martin Sedlak

Re: YBW engines past and present?

Post by mar » Wed Dec 30, 2020 7:12 pm

IanKennedy wrote:
Wed Dec 30, 2020 6:30 pm
I thought I read in the archives that Crafty used something of its own called DTS? (Distributed Tree Search).
Bob came up with DTS, but I think Crafty uses YBW, I might be wrong though, Bob will know for sure
Martin Sedlak

jdart
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Re: YBW engines past and present?

Post by jdart » Wed Dec 30, 2020 7:15 pm

Arasan used YBW before version 21.0. I don't think Crafty uses DTS - I think that was a Cray Blitz thing - but the last few versions do have some interesting mods to multithreading.

--Jon

IanKennedy
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Location: UK

Re: YBW engines past and present?

Post by IanKennedy » Thu Dec 31, 2020 8:05 am

jdart wrote:
Wed Dec 30, 2020 7:15 pm
Arasan used YBW before version 21.0. I don't think Crafty uses DTS - I think that was a Cray Blitz thing - but the last few versions do have some interesting mods to multithreading.

--Jon
That's useful to know thanks. My own program Psycho has an inefficient algorithm which could be described as YBW and also uses the idea of the 'helpful master' except mine hinders rather than helps. It was written originally for a dual processor PC in the 90s but now with lots of cores it would probably improve simply by not allocating search tasks to the master at all...
Author of the actively developed PSYCHO chess engine

Dann Corbit
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Re: YBW engines past and present?

Post by Dann Corbit » Thu Dec 31, 2020 2:55 pm

Did you try LazySMP?
Easy as falling off of a log and seems to work really well.
Taking ideas is not a vice, it is a virtue. We have another word for this. It is called learning.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.

IanKennedy
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Location: UK

Re: YBW engines past and present?

Post by IanKennedy » Thu Dec 31, 2020 4:07 pm

Dann Corbit wrote:
Thu Dec 31, 2020 2:55 pm
Did you try LazySMP?
Easy as falling off of a log and seems to work really well.
It's an option but I quite like the idea of refining the current algorithm first.
Author of the actively developed PSYCHO chess engine

Dann Corbit
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Re: YBW engines past and present?

Post by Dann Corbit » Thu Dec 31, 2020 9:52 pm

IanKennedy wrote:
Thu Dec 31, 2020 4:07 pm
Dann Corbit wrote:
Thu Dec 31, 2020 2:55 pm
Did you try LazySMP?
Easy as falling off of a log and seems to work really well.
It's an option but I quite like the idea of refining the current algorithm first.
ZCT by Zach Wegner used DTS:
https://github.com/zwegner/zct
Taking ideas is not a vice, it is a virtue. We have another word for this. It is called learning.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.

Sesse
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Re: YBW engines past and present?

Post by Sesse » Sat Jan 02, 2021 12:20 am

Dann Corbit wrote:
Thu Dec 31, 2020 2:55 pm
Did you try LazySMP?
Easy as falling off of a log and seems to work really well.
It's insane that seemingly small tweaks to what was considered the worst-scaling algorithm (shared hash table) somehow produces the best one.

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