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Little thought experiment

Posted: Wed May 15, 2019 10:05 am
by Werewolf
On another world there exists a very powerful computer using alien tech.

This chess machine does a true (as in literal) Brute Force search 15 plies deep. It uses current SF E.F

How many plies deep, approximately, would normal SF have to search to equal the strength of the 15 plies alien machine?

Re: Little thought experiment

Posted: Wed May 15, 2019 10:16 am
by xr_a_y
First, "brute force" can still be alpha/beta, I guess brute force means no forward pruning.

We can try that with depth 6 or 8 or maybe even 10 I guess ...

Is something like a limited depth no-forward-pruning-engine versus a limited time classic-engine seems fine ?

Re: Little thought experiment

Posted: Wed May 15, 2019 11:53 am
by Eelco de Groot
SF EF does not seem to do any extensions either it seems, apart from not reducing or pruning. The search horizon is only 7½ full moves. That is not enough to overcome serious horizont effects. I think it would play weakly. It is totally a guess but at first glance I'd say would be easily crushed by the better stand alones if given enough time per move, tournament time control, or maybe something like ten minutes per move, that should be enough for my old CXG Enterprise, which is not really a strong tabletop, to beat Aliens :) Image

Re: Little thought experiment

Posted: Wed May 15, 2019 12:28 pm
by Eelco de Groot
Mmm, if you set Stockfish to fixed depth 15 search but disable all extensions that would be close? Maybe still strong vs human GM but not really SF. 15 ply used to be the depth for the bench function I thought, although now it seems to be lower, just 13 ply, it tests most parts of the search in bench but takes only 2371 miliseconds for the 42 bench positions on my machine. A little more for 15 ply perhaps but if you disable all extensions seriously less than that 2371 miliseconds. 10 minutes for the CXG Enterprise would not be enough but it was not really strong.

Re: Little thought experiment

Posted: Wed May 15, 2019 5:37 pm
by hgm
Werewolf wrote:
Wed May 15, 2019 10:05 am
On another world there exists a very powerful computer using alien tech.

This chess machine does a true (as in literal) Brute Force search 15 plies deep. It uses current SF E.F

How many plies deep, approximately, would normal SF have to search to equal the strength of the 15 plies alien machine?
Why asking this for an impossibly large depth, instead of simply trying it out for depths that can be reached with present-day technology, and extrapolate from there?

Re: Little thought experiment

Posted: Wed May 15, 2019 6:01 pm
by Uri Blass
Werewolf wrote:
Wed May 15, 2019 10:05 am
On another world there exists a very powerful computer using alien tech.

This chess machine does a true (as in literal) Brute Force search 15 plies deep. It uses current SF E.F

How many plies deep, approximately, would normal SF have to search to equal the strength of the 15 plies alien machine?
Do you mean stockfish when you also disable extensions or extensions are the same as the extension of stockfish of today?

Re: Little thought experiment

Posted: Thu May 16, 2019 4:24 am
by mwyoung
Werewolf wrote:
Wed May 15, 2019 10:05 am
On another world there exists a very powerful computer using alien tech.

This chess machine does a true (as in literal) Brute Force search 15 plies deep. It uses current SF E.F

How many plies deep, approximately, would normal SF have to search to equal the strength of the 15 plies alien machine?

It would take my computer 11,367,235.62 years to make one move to match the alien computer....

Re: Little thought experiment

Posted: Thu May 16, 2019 8:53 am
by Werewolf
hgm wrote:
Wed May 15, 2019 5:37 pm
Werewolf wrote:
Wed May 15, 2019 10:05 am
On another world there exists a very powerful computer using alien tech.

This chess machine does a true (as in literal) Brute Force search 15 plies deep. It uses current SF E.F

How many plies deep, approximately, would normal SF have to search to equal the strength of the 15 plies alien machine?
Why asking this for an impossibly large depth, instead of simply trying it out for depths that can be reached with present-day technology, and extrapolate from there?
At low ply levels I imagine tactics would dominate to such an extent it might make comparison hard. Also I don't know of an engine which does a pure BF search with a SF EF. But maybe you do?

Re: Little thought experiment

Posted: Thu May 16, 2019 8:56 am
by Werewolf
mwyoung wrote:
Thu May 16, 2019 4:24 am
Werewolf wrote:
Wed May 15, 2019 10:05 am
On another world there exists a very powerful computer using alien tech.

This chess machine does a true (as in literal) Brute Force search 15 plies deep. It uses current SF E.F

How many plies deep, approximately, would normal SF have to search to equal the strength of the 15 plies alien machine?

It would take my computer 11,367,235.62 years to make one move to match the alien computer....
Yeah mine is similar, but they have great tech on planet Cybertron...

Re: Little thought experiment

Posted: Thu May 16, 2019 8:58 am
by Werewolf
Uri Blass wrote:
Wed May 15, 2019 6:01 pm
Werewolf wrote:
Wed May 15, 2019 10:05 am
On another world there exists a very powerful computer using alien tech.

This chess machine does a true (as in literal) Brute Force search 15 plies deep. It uses current SF E.F

How many plies deep, approximately, would normal SF have to search to equal the strength of the 15 plies alien machine?
Do you mean stockfish when you also disable extensions or extensions are the same as the extension of stockfish of today?
For the Stockfish engine: exactly as SF is today

For the Brute Force engine: SF EF but the search part is only BF with no extensions at all.
(Having said that another version with extensions would be interesting too)