Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Rebel9 Vs. Rebel10

Author: Ed Schröder

Date: 20:35:18 08/03/98

Go up one level in this thread


>Hi Ed,
>
>Interessting - thx!
>
>>From the 506 positions 349 of them are slower or faster than 10%.
>>
>>>>Total time Rebel9   : 02:04:57
>>>>Total time Rebel10  : 03:00:10
>>>>Total percent       : -31%
>>
>>>Does this mean in this test set, at (presumably) a fixed depth setting,
>>>R10+Anti-GM(Strong) was 31% slower than R9? (I know Strong Anti-GM
>setting is
>>>not as wise as SMART).
>>
>>Yes, fixed depth otherwise a comparison on time would make no sense. The
>>test is done with anti-GM=OFF to make a good comparison with Rebel9. The
>>-31% comes from the new search algorithm.

>Indicating more knowledge or (just a slower algorithm:))?

From my home page...
- Improved search algorithm rewritten from scratch, better tactics.
- Less selective than Rebel9, better results.

I found the selective search in Rebel9 taking too much risk at certain
points. Rebel10 is better in this respect. The negative result of such
a wider search is of course that (speaking in terms of ply-depth) it
takes a chess program more time to finish the ply (iteration).

Here are (just) 3 examples of the so called "holes" (as chess programmers
call it) in the selective search part of a chess program, in this case Rebel.

3rkb1r/p2nqppp/5n2/1B2p1B1/4P3/1Q6/PPP2PPP/2KR3R w kq - bm Rxd7
r1r2b2/pb4pk/1pB2p1p/3P1P2/8/PP2q1P1/2Q1P2P/RN2R2K b - - bm Rxc6
r2r2k1/Bpq2pbp/4p3/n3Pp2/5P1N/2P1Q3/P1P3PP/R4RK1 b - - bm Rxa7

If you test these positions with Rebel you will notice it takes Rebel a long
time to solve these (simple) positions. This because of the too small (is
risky) selective search. I even think (not tested) that Rebel Decade does
a better job in these 3 particular positions :))  Fixed in Rebel10, it only
takes a few seconds now.

If this is worth the pretty huge investment of 30%, only time can tell but
I think it does.

- Ed -


>snip again
>
>Regards,
>kim



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.