Author: blass uri
Date: 03:05:47 06/20/00
Go up one level in this thread
On June 20, 2000 at 04:11:32, Ed Schröder wrote: >On June 20, 2000 at 02:12:32, blass uri wrote: > >>On June 19, 2000 at 19:02:51, Ed Schröder wrote: >> >>>On June 19, 2000 at 13:22:31, blass uri wrote: >>> >>>>On June 19, 2000 at 11:47:12, Ed Schröder wrote: >>>> >>>>>On June 19, 2000 at 04:45:33, blass uri wrote: >>>>> >>>>>>On June 19, 2000 at 03:03:49, Ed Schröder wrote: >>>>>> >>>>>>>On June 18, 2000 at 19:46:03, Dave Gomboc wrote: >>>>>>> >>>>>>>>On June 18, 2000 at 18:21:01, Ed Schröder wrote: >>>>>>>> >>>>>>>>>On June 18, 2000 at 16:34:16, blass uri wrote: >>>>>>>>> >>>>>>>>>>On June 18, 2000 at 12:00:08, Ed Schröder wrote: >>>>>>>>>> >>>>>>>>>>>On June 18, 2000 at 10:36:40, Gian-Carlo Pascutto wrote: >>>>>>>>>>> >>>>>>>>>>>>On June 18, 2000 at 10:17:08, Ed Schröder wrote: >>>>>>>>>>>> >>>>>>>>>>>>>According Rebel it is a mate in 10. >>>>>>>>>>>>> >>>>>>>>>>>>>Ed >>>>>>>>>>>>> >>>>>>>>>>>>>00:00 07.00 0.81 1.Rxh5 gxh5 2.Rxh5 Kf8 3.Rxh7 Ke8 4.Rh8+ Kd7 5.Qf5+ Kc7 >>>>>>>>>>>>>00:01 08.00 2.37 1.Rxh5 gxh5 2.Rxh5 Kf8 3.Rxh7 Ke8 4.Qf5 Kd8 5.Qxf7 Kc8 >>>>>>>>>>>>>6.Qxe7 >>>>>>>>>>>>>00:03 09.00 2.47 1.Rxh5 gxh5 2.Rxh5 Kf8 3.Rxh7 Ke8 4.Qf5 Kd8+ 5.Qxf7 Kc7 >>>>>>>>>>>>>6.Qxe7+ Kc8 >>>>>>>>>>>>>00:43 10.00 11.74 1.Rxh5 gxh5 2.Rxh5 Kf8 3.Rxh7 e6 4.Bf6 Ke8 5.dxe6 Qxc4+ >>>>>>>>>>>>>6.Qxc4 >>>>>>>>>>>>>02:35 11.00 Mate in 10 moves 1.Rxh5 Kf8 Rxh7 2.Ke8 Rxf7 3.Qxc4 Qxc4 4.g5 Rhh7 >>>>>>>>>>>>>5.b5 Rxe7+ 6.Kd8 >>>>>>>>>>>> >>>>>>>>>>>>I find it interesting to notice that even Rebel has some trouble with this, >>>>>>>>>>>>taking more than 10 times as much time to resolve the 10th ply. >>>>>>>>>>> >>>>>>>>>>>That's pretty normal whith such big score differences (2.47 -> 11.74) as >>>>>>>>>>>search is confrontated with big score fluctuations which causes move >>>>>>>>>>>ordering to collapse. I wouldn't bother too much about it, it's quite >>>>>>>>>>>normal. >>>>>>>>>> >>>>>>>>>>Not for all programs. >>>>>>>>> >>>>>>>>>Of course. >>>>>>>>> >>>>>>>>>>Chessmaster6000(ss=10) can see a forced mate in only 4 seconds and does not have >>>>>>>>>>a big branching factor >>>>>>>>> >>>>>>>>>Sure. Maybe not in this position. >>>>>>>>> >>>>>>>>>>This is normal for chessmaster to see mates clearly faster than other programs >>>>>>>>>>and I think that this is because the other programs do some mistakes in their >>>>>>>>>>search rules. >>>>>>>>> >>>>>>>>>Nope. Johan has special (mate) stuff in his search no program has. >>>>>>>>> >>>>>>>>>Ed >>>>>>>> >>>>>>>>Just curious... why don't you add it to Rebel too? :-) >>>>>>> >>>>>>>a) because I don't know "exactly" what it is; >>>>>>>b) too much emphasis on mates loses too much elo points in games. >>>>>>> >>>>>>>Ed >>>>>> >>>>>>I think reason a is the right reason because I do not think that chessmaster >>>>>>loses too much elo points in games(chessmaster6000 is one of the top programs >>>>>>and is only one point behind Fritz5.32 in the ssdf list inspite of having no >>>>>>learning function and having an older engine) >>>>>> >>>>>>I believe that having special mate stuff is productive for chess programs if you >>>>>>do it in the right way. >>>>> >>>>>The right way? Now tell me what that is... You might ask yourself the >>>>>question if such a thing exist in computer chess. >>>>> >>>>>Finding deep mates requires extensions. Extensions mean a higher branch >>>>>factor. A higher branch factor means a lower search depth. A lower search >>>>>depth means a lower elo. >>>> >>>>The right way is to do it almost without a lower search depth. >>>>In order to do it you need to do the extensions only in the right places so when >>>>there is no mate danger you will not have lower search depth. >>> >>>The right way to do it ussue again. Ever tried to do it yourself? >>>If not try it yourself and let's talk again 4-5 years later. >> >>I did not say that it is easy to do it. >>> >>> >>>>You can also decide to have a time limit for searching with the extensions(for >>>>example 1/10 of the time per move). >>> >>>Tried it? >> >>No >>I did not say it is easy to do it but only that I believe that it is possible. >>I guess that there are more important things for you to do in the near future. >> >>> >>>It's no good. In fact it is a non working idea. When you for instance >>>find something interesting in the first part with many extensions you >>>will lose it as soon as you go back to normal search. Now that looks >>>real silly for a chess program that after (say) ply 5 finds a nice >>>tactical shot and then fails low on the 6th ply and then finds the >>>combination back on ply 9 or 10. >> >>This was not what I meant. >>I did not think to forget about what you found. >>Of course if you find something intersting(a fail high or a fail low) there is >>no reason to forget it and you can choose between only avoid doing extensions in >>nodes that you did not search and if there is a problem with doing it to >>continue with the extensions. > >And that is exactly the point. Of course you will find thousand and 10 >thousands of interesting cases you are forced to "remember" while having >no single effect on the best move. All these 10 thousands of useless >extensions are needed to extend again every iteration resulting in time >loss only. > >When you invest (say) 10% of the allowed time in a special tactical >search and it brings you nothing (which is true for almost every try) >then you don't end up with a 10% loss but with a percentage that is >much higher because of all the extensions you have to "remember". If >you are lucky you will end up with a total loss of 15-20% in a quiet >position. If you have bad luck search performance will drop with a >factor of 2-3. > >Ed I suggested to forget about the extensions if you do not find something interesting and in this case you are only 10% slower. I suggested not to forget about the extensions when you find something tactical (fail high or a fail low). Uri > > >>If you do not find something interesting you can forget about the extensions. > >>I think that it may be better in a correpondence game to use chessmaster for >>1/10 of the time when I suspect that there may be a mate danger and if >>chessmaster does not see something interesting to use another program for 9/10 >>of the time. >> >>I believe that it is better than to use only the other program. >>If I am right then the other program could be better if it knew to do the same >> >>Uri
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