Author: Uri Blass
Date: 08:46:43 12/29/03
Go up one level in this thread
On December 29, 2003 at 10:35:35, Anthony Cozzie wrote:
>On December 29, 2003 at 09:04:44, Tord Romstad wrote:
>
>>On December 28, 2003 at 22:18:04, Anthony Cozzie wrote:
>>
>>>In my personal opinion: The time of such static tricks has passed. When people
>>>ran on a 386 and struggled to get 5 ply, extensions && pruning were critical.
>>>Top programs nowadays get 14 ply. The simple fact of the matter is that
>>>computers are almost perfect tactically. More depth now is purely for
>>>positional benefit. Right now I'm trying to _reduce_ my extensions, not add
>>>more :)
>>
>>By proceeding in the same direction, you will start adding reductions. :-)
>>
>>I disagree that computers are almost perfect tactically. In the comp-comp games
>>I see,
>>a high percentage of the games are decided by a tactical mistake by one of the
>>engines.
>>You may be right that the main importance of more depth is stronger positional
>>play,
>>but I don't see this as a reason to avoid using knowledge in the search. By
>>pruning or
>>reducing anti-positional moves with no tactical potential, you will search
>>deeper positionally
>>*and* tactically.
>
>In blitz, maybe. But at longer time controls even Zappa makes almost no
>tactical errors.
You simply do not see them but it does not mean that it does not make them.
Tactical errors in calculations may mean wrong positional decisions.
>
>>You also once again make the mistake of believeing that everybody is only
>>interested
>>in making their engines play well on super-fast hardware. Programming a chess
>>engine
>>that plays well on a fast, modern PC is so easy that it is almost boring. In my
>>opinion, it
>>is much more interesting to invent techniques which do not require extreme speed
>>of
>>computation in order to work.
>
>Depends on how you define "well". Better than a human? easy. Better than
>Crafty/Yace/Ruffian? more challenging.
>
>>>Thorsten and Ed have both said that Rebel plays better with the reductions off.
>>>The only engine on ICC that uses his reductions is Chompster, and I've seen
>>>chompster make errors on a 10 ply search that Zappa catches with a 6 ply search.
>>
>>When you start a sentence with "The only engine on ICC that uses ...", the
>>statement will
>>almost always be wrong, no matter how you complete it. Gothmog ("GothmogX" on
>>ICC)
>>doesn't use exactly the same reductions as Rebel, but it does many similar and
>>often more
>>aggressive reductions (for instance, I have no upper limit for the number of
>>reductions in a
>>single path). I'm sure you'll be able to find positions where Gothmog makes
>>errors in a 10
>>ply search which Zappa catches with a 6 ply search, but I also think it is
>>possible to find
>>positions where the opposite happens.
>
>First of all, for me and I think you chess programming is a hobby, not a job.
>We are free to do whatever we want: optimize for standard time controls and dual
>opteron, or 2 minute bullet on a cell phone, or for playing an interesting game
>of chess, or for being a good sparring partner for my grandmother, or whatever.
>Being the competetive person I am, I try to make a strong engine, so that is my
>viewpoint.
>
>Secondly, I am talking about strong chess programs. Commercials + top amateurs.
> Ruffian made a tactical error at Leiden 2003. 1 error. And we were all
>amazed because it happens so infrequently. When you get 14 ply, you just don't
>make mistakes. You have to win with eval/book.
>
>Third, my point was not to derogate Chompster or Gothmog, but simply point out
>that worst case performance is what matters. What do you think is stronger: 35
>14-ply searches and 5 8-ply searches, or 40 13-ply searches?
No
It is not the way that you describe.
That is the
>problem with all static tricks: Every now and again they are wrong, and when
>they are wrong your program can lose the game in one swift swoop.
>
>I think it is possible to add 20-30 elo to your engine with static pruning.
I think that it is possible to add clearly more than it and I believe that
Gothmog already does it inspite of the fact that its static pruning is not close
to be perfect.
I will not talk about movei because there is a demage of not using hash tables
for pruning that I do not know to evaluate but I believe that the potential of
pruning is clearly more than 20-30 elo and I do not suggest to add pruning
without testing it in games.
Uri
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