Author: Christophe Theron
Date: 23:10:08 01/08/00
Go up one level in this thread
On January 08, 2000 at 23:55:58, Chessfun wrote:
>>>Cel 433
>>>Genius 5. 2kb hash = 1.f6 switches again to Kxg2 after 44 secs then solves
>>>1.f6 posting + score after 3 min 48 secs.
>>>Genius 5. 4kb hash = 1.f6 switches again to Kxg2 after 40 secs then solves
>>>1.f6 posting + score after 3 min 25 secs.
>>>Genius 5. 8kb hash = 1.f6 switches again to kxg2 after 1 min 19 secs solves
>>>1.f6 posting + score after 4 min 29 secs.
>>>Genuis 5. 16kb hash = 1.f6 switches again to kxg2 after 59 secs then solves
>>>1.f6 posting + score after 3 min 25 secs.
>>
>>
>>You mean Mb, not Kb, I presume?
>Correct.
>
>>
>>A very funny thing: Genius has almost the same problem than Tiger: at one point
>>increasing the hash table size gives a longer solution time. Then increasing
>>further yields again a better result.
>>
>I noticed that too, yet with Genius that is a little more extreme.
>Though I must admit I like these Genius programs I am a little
>surprized they didn't do better rating wise.
Hey, you never sleep? Looks like you are online all the time! :)
The Genius programs are handicaped by their branching factor. Each new ply takes
a little bit more than a new ply on other modern programs.
But they have a terrific pruning system in the last 3 or 4 plies of the search.
That means that they perform very well until, say, ply 8 or 9. After that,
almost every modern program is able to go deeper in less time, which is a
terrible handicap for Genius.
I'm sure you can check this experimentaly by comparing time to depth for Genius
and, for example, Fritz or Rebel-Tiger. Compare the time needed to complete each
new ply, and notice that the ratio (time for ply N+1)/(time for ply N) is always
higher for Genius (in average).
However I like the Genius programs a lot. Their evaluation function is one of
the best I have ever seen in term of stability. Maybe not the more accurate in
the absolute, but very homogenous. When Genius sees that it is 0.1 higher than
his opponent, it is going (generally) to keep this 0.1 until the endgame. When
it does not, it's because of lack of search depth. Genius then overlooks a
little trick, and to avoid losing more has to give back some of his positional
advantage.
In the endgame, his evaluation is simply unequaled until now. Modern programs
compensate by deeper search, but I'm not sure it's enough to equal Genius in the
endgame.
I use the term "modern programs" because I think that Genius has not seriously
evolved since several years. Probably since 1995.
Sorry for those of you who think that Genius6 and Genius6.5 are new programs.
>>>Genius 6 times are almost identical.
Strange... :)
>>>The other engines I think it is pointless exercise !.
>>>I just try one other engine MCP8 8kb hash = No solve after 18 mins.
>>>
>>>Tiger posts a + at 28 secs without going back? Genius picks 1. f6 always
>>>but not with a + score which is when it switches to Kxg2 before switching back.
>>>Trouble comes for Genius at depth 12/24 when it sees Kxg2 as better.
>>>2
>>>I'll trade yer two Genius's for a Tiger !! LOL.
>>>Thanks.
>>
>>
>>Here is the output from the Rebel-Tiger (K6-2 450MHz, 32Mb hash tables):
>>
>>
>>00:00:00.1 4.12 9 60006 a4 bxa3ep bxa3 Kg3 a4 h5 f6 gxf6 a5
>>00:00:00.4 1.12 9 83505 a4 bxa3ep bxa3 Kg3 c6 dxc6 f6 gxf6 a4 c5
>>00:00:00.3 -0.44 10 123820 a4 bxa3ep bxa3 Kg3 c6 dxc6 dxc6 Kf4 a4 Ke4
>>Kxg2 h5
>>00:00:01.8 -1.33 11 213308 f6
>>00:00:01.5 -1.16 11 263647 f6 gxf6 Kxg2 Kg4 a4 bxa3ep bxa3 Kf4 a4 Ke4
>>a5 Kxd5
>>00:00:02.1 -1.15 11 356087 c6
>>00:00:02.4 -1.14 11 445570 d6
>>00:00:03.7 -0.28 11 478497 d6 cxd6 Kxg2 Kg4 a4 bxa3ep bxa3 Kxf5 a4 Ke5
>>a5 Kd5
>>00:00:04.7 -1.17 12 611167 f6
>>00:00:04.1 -0.20 12 699197 f6 gxf6 Kxg2 Kg4 a4 bxa3ep bxa3 Kf4 a4 Ke4
>>d6 cxd6 a5
>>00:020:05.7 -0.19 12 766013 Kxg2
>>00:00:05.3 0.62 12 812882 Kxg2
>>00:00:06.4 4.16 12 1006462 Kxg2 Kg5 a4 bxa3ep bxa3 Kf6 d6 cxd6 a4 dxc5
>>a5 c4 Kf3
>>00:00:06.0 4.16 13 1006467 Kxg2 Kg5
>>00:00:10.5 1.44 14 1609096 Kxg2 Kg5 a4 bxa3ep bxa3 Kf6 a4 Ke7 a5 Kd8
>>a6 Kc8 Kh3 h6 Kg3
>>00:00:16.5 1.21 15 2565155 Kxg2 Kg5 a4 bxa3ep bxa3 Kf6 a4 Ke7 a5 Kd8
>>c6 dxc6 dxc6 Kc8
>>00:00:27.9 1.22 15 4300739 f6
>>00:00:37.3 2.34 15 6108693 f6
>>00:00:43.0 2.33 15 6946271 f6 gxf6 Kxg2 Kg4 a4 bxa3ep bxa3 Kf4 a4 Ke4
>>d6 cxd6 c6 dxc6 a5 Kd5
>>00:01:14.9 3.23 16 12181241 f6
>>00:01:56.7 5.33 16 19201142 f6 gxf6 Kxg2 Kg4 a4 bxa3ep bxa3 Kf4 a4 Ke4
>>d6 cxd6 c6 dxc6 a5 c5 a6
>>00:02:29.3 5.33 17 24464726 f6 gxf6 Kxg2 Kg4
>>00:042:22.5 5.31 18 43205717 f6 gxf6 Kxg2 Kg5 a4 bxa3ep bxa3 Kf4 a4 Ke4
>>d6 cxd6 c6 dxc6 a5 c5
>>00:09:45.2 5.00 19 96545193 f6 gxf6 Kxg2 Kg5 a4 bxa3ep bxa3 Kf4 a4 Ke5
>>d6 cxd6 c6 dxc6 a5 c5 a6 c4 a7 c3
>>00:20:04.9 5.00 19 196144774 f6 gxf6 Kxg2 Kg5 a4 bxa3ep bxa3 Kf4 a4 Ke5
>> d6 cxd6 c6 dxc6 a5 c5 a6 c4 a7 c3
>>
>>
>>I know this is not easy to read, but first column is time, second is score,
>>third is ply-depth, fourth is number of positions evaluated, and then you have
>>the best line.
>>
>>I have stopped the program exactly after 20 minutes, 4 seconds, 9 tenths. The
>>last line just repeats the last best line, as you see.
>>
>>So Tiger would play f6 very quickly, without knowing exactly why, then it would
>>play Kxg2, then sees that this is not as good as expected and would eventually
>>play f6 in about 28 seconds without changing his mind in 20 minutes.
>>
>>
>No it is clear enough 27.9 secs, I wouldn't have believed it would be that
>fast. So you got to 15 ply in only 4,300,000 positions, funny CM didn't see it I
>had that at 43,000,000.
I'm a little bit surprised too...
I think ply depth 15 does not mean the same thing in Tiger and in CM. Probably
CM does less pruning and sees more things at the same depth because it does much
more extensions? Just a guess, I don't have CM6000.
Christophe
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