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Subject: Re: Evaluation Jumps in Gambit Tiger II and other misteries...

Author: Robert Hyatt

Date: 20:23:02 04/04/01

Go up one level in this thread


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_.



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