Author: Drexel,Michael
Date: 04:37:12 01/03/03
Go up one level in this thread
On January 03, 2003 at 01:12:42, Uri Blass wrote: >On January 02, 2003 at 18:36:35, Drexel,Michael wrote: > >>On January 02, 2003 at 17:52:50, Uri Blass wrote: >> >>>On January 02, 2003 at 16:39:27, Drexel,Michael wrote: >>> >>>>On January 02, 2003 at 16:16:05, Dieter Buerssner wrote: >>>> >>>>>On January 02, 2003 at 15:53:44, Drexel,Michael wrote: >>>>> >>>>>>Hello Dieter, >>>>>[...] >>>>>>at which depth do you think it would find the mate? 30/30? >>>>> >>>>>Sorry, I am the wrong person to answer this question. How should I know? >>>>> >>>>>>this 'behaviour' has obviously something to do with its superior playing >>>>>>strength. >>>>> >>>>>? >>>>> >>>>>Regards, >>>>>Dieter >>>> >>>>just wanted to say that this kind of tests (with unreal or unlikely situations) >>>>are not important, regarding playing strength. >>>> >>>>Michael >>> >>>I disagree. >>> >>>I believe that knowing to solve the position is an advantage from playing >>>strength point of view. >>> >>>It may be unimportant if white had another win but it is not the case here. >>> >> >>In this special case it is an advantage but how often would such a type of >>position occur in the middle game? Shredder 7 and Fritz 8 (Junior and Chesstiger >>15 results would be of interest too) are not >>able to find the best move in reasonable time. >>Im not a chessprogrammer but it seems clear to me that 'comercials' are able >>to get deeper into the search, by excluding more variations then most freeware >>programs do. hence they often fail to find mates in such positions. > >I reject this explanation. >Most freeware also do not find it. I should have said most of the 'strongest' freeware programs. > >I also use pruning but for me pruning is not the main problem because even if >you give movei the position after Qxg6+ Kxg6 movei cannot find that white is >better in a reasonable time. > >pruning is important but good pruning rules should say not prune Qxg6 in that >position. > >I can give logical reasons. >1)white has inferior position without Qxg6+. >2)Qxg6+ lead to some attack for white. > >conclusion >Qxg6+ should be extended becuse it is the only chance. Stefan Mayer-Kahlens program (engine) do not extend Qxg6+ as far as I can understand. would Shredder 7 otherwise evaluate 1.Qxg6+ only 2 seconds (1.h5 about 10 minutes) at depth 17? I simply cant understand why. Doesnt Stefan know what he is doing?. I dont think so. If I would write a chessprogram, the first thing I would probably do (after the basics) is: try to make some extensions in case 'King is marching over the board in a middle game situation'. my program would evaluate 1.Qxg6+ very very long in this position. so my conclusion is: with a good opening book in mind (and shredder has good tournament book)it is not that important to have such extensions. > >Movei also searches Qxg6+ to relatively smaller depth but it only proves that my >pruning rules can be improved. > >Uri
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