Author: Christophe Theron
Date: 08:27:09 04/05/01
Go up one level in this thread
On April 05, 2001 at 09:33:21, Robert Hyatt wrote:
>On April 05, 2001 at 01:28:10, Christophe Theron wrote:
>
>>On April 04, 2001 at 23:23:02, Robert Hyatt wrote:
>>
>>>On April 04, 2001 at 19:09:19, Christophe Theron wrote:
>>>
>>>>On April 04, 2001 at 18:24:41, Robert Hyatt wrote:
>>>>
>>>>>On April 04, 2001 at 17:44:25, Christophe Theron wrote:
>>>>>
>>>>>>On April 04, 2001 at 15:20:08, Dan Ellwein wrote:
>>>>>>
>>>>>>>Christophe
>>>>>>>
>>>>>>>in regards to the following quote:
>>>>>>>
>>>>>>>"These changes are also the reason why I believe that Gambit Tiger needs a
>>>>>>>little bit more depth than Chess Tiger to achieve its full strength. At very
>>>>>>>shallow ply depths, there is too much uncertainty for Gambit. It needs more
>>>>>>>depth to find stable king attack plans."
>>>>>>>
>>>>>>>Is it accurate to say that Gambit Tiger plays better at longer time controls...
>>>>>>
>>>>>>
>>>>>>No, it is not what I'm claiming here.
>>>>>>
>>>>>>What I am saying is that Gambit Tiger is not suited for very slow computers.
>>>>>
>>>>>Sorry, but those two statements are the _same_ thing:
>>>>>
>>>>>1. GT needs a faster processor to do ok;
>>>>>
>>>>>2. GT needs more time to do ok;
>>>>
>>>>
>>>>
>>>>It's a matter of scale.
>>>>
>>>>I have made a few test games with Gambit Tiger 1.0 on a 20MHz computer, and it
>>>>performed poorly because it was playing too obvious attacking moves that could
>>>>be refuted just by looking a few plies deep.
>>>>
>>>>These were games in 10 minutes, and the program routinely reached 4 to 5 plies.
>>>>
>>>>On the other hand, look at the results of Gambit Tiger on current hardware at
>>>>game in one minute (some results have been posted today) and you will see that
>>>>this problem completely disappears very quickly.
>>>>
>>>>If you want to deduce from this that "Gambit plays better at longer time
>>>>controls", very well. But it's of course not the case.
>>>>
>>>>And Gambit Tiger does NOT need a faster processor to do OK, unless you are
>>>>talking about 5MHz computers.
>>>>
>>>>And Gambit Tiger does NOT need more time to do OK, unless you are speaking about
>>>>0.05s per move.
>>>>
>>>>
>>>>Just check the posted results if you want to be sure.
>>>>
>>>>
>>>>
>>>> Christophe
>>>
>>>
>>>OK... I'll bite on this discussion.
>>>
>>>1. I do _not_ believe that you have a "magic depth" that once you reach that,
>>>you don't need more. If a slow machine doesn't search deep enough, while a
>>>faster machine does, I don't believe that is a "unit step function". I believe
>>>it is a "continuous function" so that as the hardware gets faster, the
>>>advantage continues to accrue. Otherwise you could find some magic depth and
>>>say "if I search below this I get killed, if I search above this, I never
>>>have a problem."
>>>
>>>2. I have seen the _same_ problem in my program. My aggression is not so much
>>>directed at king safety, as it is directed at avoiding blocked positions that
>>>human IM/GM players strive for. But at very shallow search depths, it will
>>>make mistakes that it can't defend later, while at reasonable time limits, it
>>>will not make aggressive counter-moves that ultimately lead to a quick loss
>>>of material somewhere. There is a steady improvement as depth increases...
>>>
>>>I don't see why such an idea is bad or wrong either. It seems intuitive to
>>>me...
>>>
>>>And don't forget, you can double the time per move, or double the clock speed
>>>of the processor. The effect is _identical_.
>>
>>
>>
>>Maybe you are right, Bob.
>>
>>What I said is based on a few games I have played with Gambit Tiger 1.0 on a
>>very slow computer, at a time control of game in 10 minutes. What I have seen
>>convinced me to stop using Gambit Tiger on this kind of computer, at that time
>>control.
>>
>>But I should maybe try again and maybe with enough games Gambit would eventually
>>turn out to be as useable as Chess Tiger on slow computers.
>>
>>
>>
>> Christophe
>
>
>I run into real problems with null move and shallow depths, as I have reported
>before. This is one reason crafty is not a great bullet chess player. Yes,
>against humans it is usually murder. But against a "safer" type of pruning, it
>does very badly at 1 0 games.
The problems you have with null move at shallow depths come from your QSearch
which is too simple.
Christophe
> It does better at 5 3 games. Even better at
>40/2hr games, and at 2 hours+ per move (ie Ed's 2010 experiment) it has no
>problems at all that I could see.
>
>I think the more aggressively you play, the more this becomes evident, too. As
>a "safe" program doesn't hang things out in the wind. But an aggressive program
>can be led to do so by the evaluation, unless the search refutes the idea.
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