Author: Vincent Diepeveen
Date: 13:22:58 09/20/05
Go up one level in this thread
On September 20, 2005 at 15:27:14, Bruce Moreland wrote: >On September 20, 2005 at 13:16:35, Robert Hyatt wrote: > >>On September 20, 2005 at 12:59:03, Uri Blass wrote: >> >>>On September 20, 2005 at 11:58:35, Robert Hyatt wrote: >>> >>>>On September 20, 2005 at 02:35:50, Bruce Moreland wrote: >>>> >>>>>On September 18, 2005 at 14:47:26, Robert Hyatt wrote: >>>>> >>>>>>On September 18, 2005 at 14:38:27, Uri Blass wrote: >>>>>> >>>>>>>On September 18, 2005 at 13:59:18, Robert Hyatt wrote: >>>>>>> >>>>>>>>On September 18, 2005 at 12:00:09, Vincent Diepeveen wrote: >>>>>>>> >>>>>>>>>On September 18, 2005 at 10:45:19, Robert Hyatt wrote: >>>>>>>>> >>>>>>>>># Name 1 2 3 4 5 P BU SB G >>>>>>>>>1 Deep Thought II 2w1 5b0 7w1 3b1 5b1 4 13½ 11 5 >>>>>>>>>2 Zarkov 1b0 6b1 4w1 5b= 3w1 3½ 15 9¾ 5 >>>>>>>>>3 Star Socrates 10w1 7b1 5w1 1w0 2b0 3 12½ 5 5 >>>>>>>>>4 Now 6w= 10b= 2b0 8w1 9b1 3 10½ 5½ 5 >>>>>>>>>5 Mchess Pro 8b1 1w1 3b0 2w= 1w0 2½ 16½ 7¾ 5 >>>>>>>>>6 Cray Blitz 4b= 2w0 9w1 7b0 10w1 2½ 11 4 5 >>>>>>>>>7 Wchess 9w1 3w0 1b0 6w1 8b0 2 13½ 4½ 5 >>>>>>>>>8 Evaluator 5w0 9b0 10w1 4b0 7w1 2 10 2½ 5 >>>>>>>>>9 Innovation II 7b0 8w1 6b0 10b1 4w0 2 10 2½ 5 >>>>>>>>>10 Spector 3b0 4w= 8b0 9w0 6b0 ½ 12½ 1½ 5 >>>>>>>>> >>>>>>>>>Zarkov from those days had no problems beating your 3 million nps Cray Blitz. >>>>>>>>>Nor had Wchess problems beating your 3 million nps Cray Blitz. >>>>>>>>> >>>>>>>> >>>>>>>>Ask John about the game. First, this was a 500K program for rounds 2-4. And >>>>>>>>when you ask him, he'll tell you about our rather severe crash problem due to a >>>>>>>>missing test to limit ply to 64 or less. And in a couple of cute places, we >>>>>>>>went beyond that limit, crashed, and burned. We fixed it for the last round, >>>>>>>>but it really didn't matter to the final results. >>>>>>>> >>>>>>>>But notice the issue was about deep thought, _not_ about Cray Blitz. Did you >>>>>>>>see any of the micros coming close? (hint: round 2 was a forfeit which is why >>>>>>>>they were paired a second time, round 2 never got started for the DT MCP game). >>>>>>> >>>>>>>Deep Thought was significantly better than the micro of 1995 >>>>>>> >>>>>>>Uri >>>>>> >>>>>>I am well aware of that. And DB was 100x faster than deep thought 2, and also >>>>>>had a better evaluation... >>>>>> >>>>>>that was my point in all this... >>>>> >>>>>I think that Hsu is a pretty arrogant person, after having read some stuff that >>>>>he has said about himself and other chess programmers. >>>>> >>>>>Read his book, if you can stand it. >>>> >>>>I did. It didn't particularly turn me off. But then I have had dozens of >>>>face-to-face conversations with him dating back to 1987 in Orlando at the ACM >>>>event that year, continuing thru the point where he left IBM a few years back. >>>> >>>>> >>>>>For years you have taken a few things he has said as truth, but given his >>>>>personality I am not sure if they are true. He may think they are, but this >>>>>doesn't mean that they are. >>>> >>>>That is probably all in perception. I took very little of what he said at face >>>>value, without supporting evidence. He was usually more than happy to sit down >>>>with deep thought and play with positions to see how it would react. And he >>>>never wanted to "hide" the display so I could not see. I didn't trust the SE >>>>data, since they gave conflicting reports on the effect (was it +70 or +7 rating >>>>points better) so I simply tried it for myself in Cray Blitz. And I think that >>>>+7 was closer to the truth although in the right positions it was much more than >>>>that... >>>> >>>> >>>> >>>> >>>>> >>>>>He hung you out to dry by leaving you as primary defender of Deep Blue for >>>>>years, while he left the trivialities of computer chess to mere mortals like us. >>>>> The DB project doesn't deserve defense. It hit computer chess like a >>>>>carpetbagger, then left in the night when the money was gone. >>>>> >>>>>bruce >>>> >>>> >>>>However, I would not attribute that to Hsu or Campbell. They were active in >>>>computer chess for many years. IBM pulled the plug for obvious reasons after >>>>they hit the peak of Mt. Everest... >>>> >>>>I'll always have a great deal of respect for the group. PVS search was first >>>>used in my program by accident, as Murray and I played with it at an ACM event >>>>on a machine we were not using, but a machine we had to use due to a power loss >>>>during a key round. Singular Extensions was Hsu's idea, and it certainly >>>>worked, since many are using it today in various forms. >>> >>>I know nobody who use it in the way that Hsu used it. >>> >>>Uri >> >> >>Several have used PV-singular as defined by Hsu. Kittinger was one, Lang was >>another. I'm not sure anyone did the FH-singular extension as defined by Hsu >>because it is _very_ costly. But I did it in Cray Blitz and it worked just >>fine. I tried it in Crafty and it didn't work just fine. Whether that was a >>result of the null-move stuff with R=2/3, vs Cray Blitz with R=1, I don't really >> know since I was not interested in crippling Crafty's search to try them >>further... >> >>One day I might, again... >> >>However, just because no one did FH-singular doesn't mean the idea is wrong. No >>one does it because of the cost. When you are 1000x faster than your nearest >>competitor, you can give up a factor of 10x to implement something like that, >>and _still_ be 100x faster than them which is more than enough to avoid >>trouble... >> >>People copy ideas that work well with low cost, they often avoid things with >>high cost because that cost will more than offset the gain if you don't have >>special-purpose hardware to hold the cost down. I could make a list of a few >>key endgame features that appeared in Crafty before they were in any commercial >>programs. Outside passed pawns in 1995 is one. Then candidate passed pawns >>(distant majorities). etc. If you go back to 1976 and "blitz" we had the >>"passed pawn race" code already in place so that we could detect uncatchable >>passed pawns in king and pawn endings. Most everyone does that today. Because >>the costs are more than offset by the gains. FH-singular might not be there >>yet, but that is why no one is using it, not that it does not work. Because it >>is clearly correct theoretically. Just too expensive practically... > >It also mean that it does work. When your competition is out-gunned, everything >you do works, including the stuff that doesn't work. > >This is not to say that the stuff doesn't work. If you want an example of >someone who does FH singular extension, albeit in restricted form, look at me. >When I fail high I keep searching at reduced depth, although not all the time. > >DT/DB may have been a great system. I don't know, because I don't trust the >information that I have seen about it, and I can't examine it for myself. > >I don't trust the DB guys to make the determination. You can listen to any >number of people talk about how their program is super-advanced and does this >and that, and when you play the program on equivalent hardware, it sucks. > >Hardware can mask a lot of problems. Essentially you said so yourself when you >talked about DB "giving up a factor of 10" to SE. > >I would be absolutely insane to "give up a factor of 10". My program gives up a >ply due to its use of SE, but it doubles its tactical speed. So I gave up >nothing -- SE doubles my program's speed, by my estimation, despite reducing its >average depth. That is the world I operate in. If something makes my program >suck, I have to remove it, because I can't afford to suck, because other people >who don't suck have big enough hammers that they can break my skull if I do. >This is very Darwinian. Something that is occupies a niche by itself can afford >to be inefficient. Once it has competitors who make use of the same resources, >it had better become efficient unless it wants to end up obsolete. > >Honestly, none of the big iron seems very efficient to me. You invented a lot >of techniques, and you deserve to be one of the first few guys in the CC hall of >fame, but I bet you got a lot better when you had to fight Fritz on equal >footing. > >bruce Please realize 1 factor. At 480 cpu's using SE is very difficult. The huge number of tiny searches it generates are a major problem. In fact i made special splitting code in order to be able to use SE at a quad even. It scales the program better already at a quad. At 16 cpu's i couldn't run with SE initially without making the special splitting code. Above 16 cpu's, forget using SE. Too many tiny searches. SE loses diep less than a ply usually. Usually about 0.5 ply. The problem i have with SE is that in testgames it scores better without SE, because that 0.5 ply is an extra "positional 0.5 ply" whereas SE is just tactical and at 14 ply search depths there is no magic tactics that win the game suddenly. Only in testsets there is. Additional SE sees tactics after the game has been decided already. When you need it, like in seeing perpetual check, something that does make sense to see, then it doesn't see it. Vincent
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.