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Subject: Re: Rybka 38.5 Movei 1.5 ?

Author: Uri Blass

Date: 19:24:44 12/07/05

Go up one level in this thread


On December 07, 2005 at 11:49:03, Uri Blass wrote:

>On December 07, 2005 at 11:36:06, Laszlo Gaspar wrote:
>
>>On December 07, 2005 at 10:43:28, Uri Blass wrote:
>>
>>>On December 07, 2005 at 10:01:33, Laszlo Gaspar wrote:
>>>
>>>>On December 07, 2005 at 07:25:26, Tord Romstad wrote:
>>>>
>>>>>On December 07, 2005 at 05:31:51, Barry Culp wrote:
>>>>>
>>>>>>On December 06, 2005 at 23:11:38, Uri Blass wrote:
>>>>>>
>>>>>>>results of more matches
>>>>>>>
>>>>>>>Rybka(2 plies)-Movei(4 plies) 12.5-7.5
>>>>>>>Rybka(3 plies)-Movei(5 plies) 7.5-12.5
>>>>>>>Rybka(4 plies)-Movei(6 plies) 11-9
>>>>>>>Rybka(5 plies)-Movei(7 plies) 10.5-9.5
>>>>>>
>>>>>>What's the point of running these handicap matches ? Please explain
>>>>>
>>>>>It is commonly believed that the difference between a search to
>>>>>depth N and a search to depth (N+d) is less significant when N is
>>>>>big.  This seems intuitively plausible, but as far as I know we
>>>>>don't have much experimental support for this hypothesis.
>>>>>
>>>>>Experiments like Uri's could help us to learn more about this.
>>>>>
>>>>>Tord
>>>>Dear Tord and others,
>>>>
>>>>This is my first post on this forum but I would like to share my experience in
>>>>this topic, since I also have an own engine and researched a bit in this
>>>>direction. Interesting but I found that every ply increase in search gives an
>>>>almost same ELO increase. This means that my weak engine which is let's say 450
>>>>ELO weaker than Fruit at depth=4 is almost equal at depth=6 (when Fruit remained
>>>>at 4 ply) and better with depth=7 and so on. This increase seems to be different
>>>>but constant in relation of two specific engine and it's around 200ELO, which is
>>>>quite big.
>>>>I think this is very important to know and it has quite a few consequenses:
>>>>
>>>>1. Any dumb engine can be champion on a fast hardware.
>>>
>>>I disagree about it.
>>>I do not believe tscp can be a champion on a fast hardware.
>>>
>>>>2. You can improve your engine quite a lot if you improve the evaluation
>>>>function only or tune your extensions.
>>>
>>>I agree.
>>>>3. You can neglect the evaluation function and concentrate on search only to
>>>>reach higher depth.
>>>
>>>You can do it and get improvement but you will miss possible improvement.
>>>
>>>>4. Not important to search everything to high depth just the important
>>>>lines(extensions, reductions).
>>>
>>>I agree.
>>>>5. Time management is important.
>>>
>>>I agree.
>>>>6. Testing development version of an engine can be more simple, since a fixed,
>>>>low depth test match can be done quickly.
>>>
>>>I agree.
>>>>7. In my opinion the ELO rating can be estimated for any time control by simple
>>>>maths though still I didn't figure out the exact formulation (we have to
>>>>calculate the average search depth for a specific TC, which is not hard if we
>>>>know the average branching factor).
>>>
>>>I do not think that it is so simple.
>>>
>>>>
>>>>In the view of these I consider Uri's data very interesting and useful although
>>>>the number of games is low to justify the aboves.
>>>>
>>>>Best regards,
>>>>László
>>>
>>>I run now a match of movei against tscp
>>>I think that I believe that I can let tscp outsearch movei by more plies if the
>>>depth is bigger and still win but we are going to see(note that movei does mopre
>>>pruning and more extensions(checks in the qsearch) so I may change movei to use
>>>similiar algorithm as tscp for comparison later.
>>>
>>>first match was
>>>Tscp(5 plies)-Movei(4 plies)
>>>
>>>Result is 15.5-4.5 for Movei
>>>
>>>second match is tscp(6 plies)-Movei(4 plies)
>>>tscp is leading 5.5-1.5 for tscp at this moment(no wins for movei so far).
>>>
>>>Unfortunately I am afraid that more plies for tscp may take a long time.
>>>
>>>I expect movei to lose with 4 plies against 6 plies of tscp but to win with
>>>6 plies against 8 plies of tscp but I may be wrong about it.
>>
>>Hi Uri,
>>
>>When I sad in my first statement that "on a fast hardware", I meant fast enough
>>:-)! It can be 100 or 1000 or more times than the opposition's one.
>
>100 or 1000 is not enough for tscp to beat other programs even if you remove
>some problems that make it unable to search more than 32 plies and you need
>probably more speed.
>
> And if it is
>>fast enough it will play good chess...This is important because relatively big
>>differences can be equalized by speed.
>
>I agree that enough speed can compensate.
>
>>I think your test against TSCP will also justify it. (I 'm glad you do it!) But
>>it is not sure at all that if TSCP wins in the 6 to 4 ply match then the same
>>result would happen in case of 8 to 6. But the 9 ply TSCP will be better again
>>than the 6 ply Movei and so on.
>
>I agree about this.
>
> This is because the ELO increase constant can be
>>different for TSCP and Movei in their relation, let's say 180 for TSCP and 250
>>for Movei and Movei improves faster.
>>
>>I' m waiting for your findings with interest!
>>
>>Best regards,
>>László
>
>6 vs 4 plies was 14-6 for tscp
>7 vs 5 plies is running at this moment and result so far is 0.5-0.5
>
>Uri

results so far

Tscp wins
6 vs 4 14-6
7 vs 5 15-5

Movei wins
4 vs 5 15.5-4.5 this seems too optimistic so I played the match that is
considered by chessbase as the nunn2 match(not the original one) and the result
in it was 29.5-20.5 so the total result is 45-25
5 vs 6 13-7

It seems that tscp can win also 8 vs 6 based on the data but I suspect that
movei does more pruning than extensions at high depthes so I may try version
with no pruning.

Uri



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