YBW engines past and present?

[IanKennedy]

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.

[mar]

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.

[IanKennedy]

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).

[mar]

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

[jdart]

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]

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...

[Dann Corbit]

Did you try LazySMP?
Easy as falling off of a log and seems to work really well.

[IanKennedy]

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.

[Dann Corbit]

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

[Sesse]

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.