Author: Robert Hyatt
Date: 11:39:58 04/05/01
Go up one level in this thread
On April 05, 2001 at 11:27:09, Christophe Theron wrote: >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 > > I like it simple. :) But in any case, if I did the older style q-search I used to do, it would only change things slightly. Null-move still knocks off 2-3 plies of depth, which will hide things that any q-search can't recover from... > > >> 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.
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.