Author: Robert Hyatt
Date: 07:40:36 08/30/00
Go up one level in this thread
On August 30, 2000 at 09:45:45, Wayne Lowrance wrote: >On August 30, 2000 at 04:47:49, Uri Blass wrote: > >>On August 30, 2000 at 04:34:08, Ricardo Gibert wrote: >> >>>On August 30, 2000 at 02:42:49, Uri Blass wrote: >>> >>>>On August 30, 2000 at 00:31:24, Ricardo Gibert wrote: >>>> >>>>>On August 29, 2000 at 23:19:59, Robert Hyatt wrote: >>>>> >>>>>>On August 29, 2000 at 19:18:17, Alexander Kure wrote: >>>>>> >>>>>>>On August 29, 2000 at 13:58:52, Graham Laight wrote: >>>>>>> >>>>>>>>Firstly, apologies to everyone for dashing off after the last game in the WMCCC. >>>>>>>> >>>>>>>>It enabled me to get an extra day's holiday with my girlfriend, though, which >>>>>>>>was well worthwhile! >>>>>>>> >>>>>>> >>>>>>>Well deserved, Graham! >>>>>>>Thanks again for your work. >>>>>>> >>>>>>>[...] >>>>>>> >>>>>>>This game clearly showed that Fritz plays in a different league than Crafty! In >>>>>>>fact I think this was one of the best games of the WMCCC. >>>>>>> >>>>>>>Greetings >>>>>>>Alex >>>>>> >>>>>> >>>>>>My take on this game is a bit different. I do _not_ want my program to make >>>>>>such a sacrifice and then see the eval steadily go _down_ over the next few >>>>>>moves. It means one of two things for it to win such a game: >>>>>> >>>>>>1. The eval is bogus. It is saying "this is bad" when in reality "this is >>>>>>good". I don't want that sort of evaluation. >>>>> >>>>>But this is unavoidable. Otherwise computer programs would only need to do a 1 >>>>>ply search. >>>>> >>>>>> >>>>>>2. The program was lucky. A little luck doesn't hurt. But it doesn't win >>>>>>tournaments very often. >>>>> >>>>>Again, unavoidable. Have crafty play against itself and you will still have >>>>>decisive games. The games are won due to luck, since they have the same eval. >>>>>The question is, "did Fritz make a good gamble?" >>>>> >>>>>> >>>>>>Either the eval was wrong, or it was lucky. Neither one leave me feeling like >>>>>>"fritz is in a different league than Crafty..." >>>>> >>>>>Of course, but that is pretty much how _all_ games are decided isn't it? >>>> >>>>No >>>> >>>>There are games when one side get advantage and slowly increase the advantage >>>>without having a worse position. >>> >>>The only truly correct evals are a: win, draw or loss. The other stuff in >>>between are _practical_ assessments that do not correspond to the true >>>evaluation of the position, but they are precisely what all programs rely on in >>>all games. Yes? >>> >>>> >>>>> >>>>>> >>>>>>I suspect white has better moves that might have justified the pessimistic eval >>>>>>Fritz had... The right program might have made that sacrifice look as ugly as >>>>>>this game made it look brilliant... >>>>> >>>>>Better moves may exist, but you have to _find_ them. >>>> >>>>Crafty could find Nxe6. >>> >>>If Nxe6 is an improvement for crafty, it had to find it during the game and not >>>after. Why it didn't is irrelevant to the result. The result still stands. >> >>The result stands but the impression that fritz is a different league than >>crafty does not stand. >> >>Uri > >I have both programs. It stands, has been that way for a long time ! Fritz found >a move that Crafty could not find an answer for, all of the other stuff is >excuse making ! >Wayne I'm not trying to make _any_ excuses. Crafty lost. That happens. The issue (to me, now) is simply "did it _have_ to lose that game, was the sac sound, if not, why didn't it find the right response?" I always analyze losses to see what went wrong, otherwise there would be no way to make it play better. There are two ideas here: (1) if it should have found Nxe6 but didn't, then that changes things a lot. IE it shouldn't have lost but did due to operator error, my error, or a programming problem. (2) if it couldn't find Nxe6 on the hardware it had, period, then the discussion is now not about Crafty, but about Fritz, since it played a bad move but the opponent didn't punish it correctly. In that case, Fritz needs some tuning as it won't always get away with playing such a sac. There is no sense in a program impaling itself on its own sword...
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