[Pachi] Pachi became strongest Go program on desktop systems. Are there any prospects?

Stanisław Halik sthalik at misaki.pl
Fri Aug 8 18:55:11 CEST 2014


On 2014-08-08 17:53, Petr Baudis wrote:
>> For analysis while You get fixes and strength enhancements it may be helpful to see played games from here: ..snip.. (most of them played with 2 minutes per move, 2 cores and 8 GB of memory for each program).
>> You can compare how stronger became Pachi, for example, by sparring its versions with MoGo4.86 (./mogo --19 --time 120 --pondering 1 --nbThreads 2 --collectorLimitTreeSize 800000 --loadOB totalOB.ob). For example also, in these games Pachi compiled with: DOUBLE=1 in Makefile; spatial_hash_bits 30  in patternsp.h and used Patterns: gogod-handikgspachi-iter; was launched with: ./pachi -f book.dat -t 120 threads=2,max_tree_size=4096 (may be there are more strong launch variant for this amount of time, cores and memory?).
>    Hmm, any particular reason for setting DOUBLE=1 ?  I think that will
> just slow things down, it should make sense only for huge numbers of
> playouts.

That is, will make locality worse?

FWIW, still remember the discussed project to do with removing needless 
indirection.

Since discussing it on IRC was a pain... is node sibling pointer needed 
when turning child node pointers galore into an array? There was code 
that relies on the sibling pointer, and hardly able to make it up to 
spec without getting the underlying idea.

Given how more evaluations are a win, and improving locality assumed to 
make a non-insignificant improvement, the deal could use a roadmap and a 
guide, from someone who solely knows abstractions and other structure in 
the codebase.

PS when reading commit diffs I cringe on how tricky the logic for the 
game rules and what the game rules _imply_. Eye filling rules, 
oft-dreaded selfatari, etc.

If selfatari etc. are to be redone in a more idiomatic, elegant fashion, 
is there any prior art for reasoning about groups, tsumego etc? If 
there's no prior art that's another matter.

Hope meaning of the message doesn't escape you pasky, as there's hardly 
any context to go with it. Still, perhaps you log your IRC or maybe even 
remember what we talked about.

-sh


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