Author: Uri Blass
Date: 12:08:38 09/10/01
Go up one level in this thread
On September 10, 2001 at 13:25:47, Robert Hyatt wrote: >On September 09, 2001 at 08:27:50, Amir Ban wrote: > >>On September 08, 2001 at 23:24:41, Robert Hyatt wrote: >> >>>On September 08, 2001 at 14:07:22, Gian-Carlo Pascutto wrote: >>> >>>> >>>>The question was a post where DB saw something the current >>>>programs can't see. This is one. >>>> >>>>-- >>>>GCP >>> >>> >>>I wish I could give more information about "the position". All I recall is >>>that Bert and I were sitting at the table, with Murray and Hsu on the other >>>side. Hsu left to go to the restroom. after a couple of minutes into a >>>search (I don't recall whether it was a ponder search or right after we had >>>made a move) murray noticed that the program had failed high. He commented >>>"it is picking on your bishop and the score just jumped." When I asked him >>>"how much" he said "+2". Since we were not seeing any problem, Bert and I >>>were assuming they had some sort of quirk in the hardware or software. But >>>our score steadily dropped until several moves later the bottom dropped out >>>and we were at -2 or so. >>> >>>I remember that the problem started on the move of the c-pawn, as discussed >>>a year ago or so. And at that point their search failed high. I don't recall >>>the depth. I do remember that in their PV (the part displayed by the software) >>>they indicated which moves were singular-extended, and most of them were in >>>that particular position. >>> >> >>27...c5 doesn't win material, and it's easy to see this by the way the game >>continued. >> >>White's 34.Nb2 is an unforced blunder. >> >>White can play better earlier, like 32.Bg5, and it's black advantage but not >>more. >> >>All this has been pointed out before. What we are asked to believe here is not >>only that DT saw a (non-existent) combination no one else can find, but that so >>did Cray Blitz. >> >>Amir >> > > >A couple of things. > >1. I obviously can't be certain about what DT saw. I personally saw their >score. I personally saw their PV although as I mentioned before, their PVs >are always short since the hardware doesn't back them up and the hash table >is not always a reliable source for obtaining a PV. IE I know what I saw >during the game. > >2. I obviously can't be certain that their +3 eval (really more like +2.4 >when you factor out their pawn value) was due to something forced vs something >that was due to a bug in their search or hardware. I wouldn't know how to >prove that even if I had their hardware in my office. I saw Cray Blitz play >what appeared to be an ugly move against Nuchess in the 1984 ACM tournament, >only to discover that it gave NuChess the opportunity to make a fatal error >that would lose the game, which it promptly did. We could never reproduce that >move again. Was it a bug? Was it a hashing artifact? Was it cosmic rays? >No way to prove this, period. So proving whether their fail high was a bug or >real is not going to be very easy. > >3. Cray Blitz did _not_ see the combination. It blindly played on, with its >eval slowly dropping, until it finally saw it was in trouble. If you want to >say they won because we played poorly, perhaps that is right. Perhaps what you >call a blunder is really a reasonable move _if_ your program can see deeply >enough to realize it is already in trouble at that point. Again, this is >difficult to prove, and probably not worth the effort either, since those that >don't want to believe DT/DB was very strong are not going to believe it no >matter what evidence is shown, and vice-versa. > >I personally prefer to rely on logic. And logic tells me that a machine that >can search 200X faster than mine is going to be far stronger than mine. the game was Deep thought's game and not Deeper blue's game so it was not 200Xfaster than yours They >proved this over a long period of time via WCCC and ACM tournaments. They then >proved it against Kasparov and other GMs at the various exhibition matches they >played. If you really think your programming skills are enough to offset their >200X speed advantage, knowing Murray, Hsu, and the rest, then that is just an >opinion you will have to keep. Amir did not say that his programming skills are better than Hsu's skills and he did not say that he could do better than Hsu in his situation. Hsu did not have the hardware like Amir but had to develop the hardware. Using available hardware that is 200 times faster and developing hardware are different things. Claiming that deeper blue was not better than the top programs of today is not a personal attack against Hsu. You also did not need to develop the hardware when you worked on Cray blitz so your situation was not similiar to Hsu's situation. Uri
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