Author: Ricardo Gibert
Date: 23:01:16 05/28/03
Go up one level in this thread
On May 28, 2003 at 23:01:16, Robert Hyatt wrote: >On May 28, 2003 at 19:36:27, Ricardo Gibert wrote: > >>On May 28, 2003 at 14:55:10, Robert Hyatt wrote: >> >>>On May 28, 2003 at 11:17:00, Ricardo Gibert wrote: >>> >>>>On May 28, 2003 at 11:00:06, Robert Hyatt wrote: >>>> >>>>>On May 28, 2003 at 00:57:00, Ricardo Gibert wrote: >>>>> >>>>>>On May 28, 2003 at 00:10:32, Robert Hyatt wrote: >>>>>> >>>>>>>On May 27, 2003 at 19:11:49, Jorge Pichard wrote: >>>>>>> >>>>>>>>After being completely out-played for the entire game, and with imminent defeat >>>>>>>>on the horizon, Kasparov resigned the 2nd game rather than drag out the >>>>>>>>humiliation. But Deep Blue had made a critical error, allowing Kasparov a >>>>>>>>perpetual check. The analysis is quite deep and extends slightly beyond Deep >>>>>>>>Blue's search horizon. And, apparently, also Kasparov's. Kasparov's team, which >>>>>>>>included Grandmaster Yuri Dokhoian and Frederic Friedel, were faced with the >>>>>>>>delicate task of revealing the news to Kasparov. They waited until lunch the >>>>>>>>next day, after he had had a nice glass of wine to drink. After they revealed >>>>>>>>the hidden drawing resource, Kasparov sunk into deep thought (no pun intended) >>>>>>>>for five minutes before he conceded that he had missed a draw. He later claimed >>>>>>>>that this was the first time he had resigned a drawn position. >>>>>>>> >>>>>>>>Six years later, which program can see the draw in the famous 2nd game of the >>>>>>>>rematch? >>>>>>>> >>>>>>>>Jorge >>>>>>> >>>>>>> >>>>>>>NO program sees this. It is about 60 plies deep. It is unlikely that a >>>>>>>program will see it for quite some time to come, in fact... >>>>>> >>>>>> >>>>>>Whenever this comes up, you always say "about 60 plies", but I can't find >>>>>>anything to corroborate this. Let's see your analysis. >>>>> >>>>>The best analysis I specifically remember was posted on Ed's web site a few >>>>>years ago. I didn't save it as it was not particularly "interesting" to me. >>>>> >>>>>It might still be available however... >>>> >>>> >>>>http://www.rebel.nl/db2.htm >>>> >>>>He only gives 36 plies. A far cry from "about 60 plies" >>> >>> >>>OK... then that may not be the deepest drawing line. >>> >>>However, he does point out the difficulty of finding one particular non-checking >>>move way deep into the tree... >> >> >>While one could argue whether or not a program like Yace or Fritz can actually >>"see" the draw from the root position, there is little question that they would >>actually "play" the draw. This is an easy experiment to perform and you will >>find this includes the move you allude to. > >I've done that myself and I agree. However, following the moves to a draw >is not the same thing as recognizing that the game is a draw at the point in >question. > >Of course, just eventually stumbling into the draw by playing reasonable >moves is a good first approximation. But I'd prefer to see a program understand >from the beginning that this is drawn and why this is so... ie evaluate the >various positions along the way correctly. > > >> >>There is a more interesting experiment that I would like to see Yace perform. It >>would require modification to the program, however. That is to have it perform a >>test to see if the position after the ...Qc1 move occurs plus to verify that it >>correctly evaluates it. >> >>BTW, I think this type of test should be a standard feature of programs that can >>be turned on/off. How else to know to determine with a high degree of confidence >>whether a program "understands" a given position or not? > > >It's a huge headache. I could do this in the 1970s because the tree size >was small enough to print the _entire_ thing. Not today when it could >easily pass one billion lines of output. And if you are talking about >searching overnight, forget it. :) I agree that your take on what I said is completely impractical. I'm just talking about a test for *single* position plus a *single* associated eval. In short, a boolean test to make sure that what a certain desirable thing does indeed happen. All it would do is set a flag that you can check after the search is stopped. That's it. Nothing elaborate.
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