Author: Robert Hyatt
Date: 06:33:21 04/05/01
Go up one level in this thread
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. 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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