Author: Vincent Diepeveen
Date: 04:06:20 07/03/05
Go up one level in this thread
On July 01, 2005 at 21:38:28, Robert Hyatt wrote: >On June 30, 2005 at 21:47:25, Robin Smith wrote: > >>On June 30, 2005 at 20:29:42, Robert Hyatt wrote: >> >>>On June 30, 2005 at 16:08:32, Andreas Guettinger wrote: >>> >>>>On June 30, 2005 at 11:34:18, Evgeny Shu wrote: >>>> >>>>>http://chessbase.com/newsdetail.asp?newsid=2485 >>>> >>>> >>>>Now this surprises me a bit: >>>> >>>>"I wasn’t really concerned about that possibility. In any case it would be >>>>impossible for me to tell, because Hydra plays a very different game to any >>>>other computer that I ever saw. Even in these six games it actually played >>>>differently to anything I saw in its own previous games, so it’s not easy to >>>>judge. But no, I don’t have any suspicions about human intervention. That’s not >>>>something that concerned me." >>>> >>>>A replayed the matches live on Hiarcs 9.6 and Fruit 2.1 on my 2 computers, and I >>>>would say above 95% of Hydras moves were suggested by at least one of them. >>>>Especially Fruit did very well in predicting Hydras moves. >>>>Therefore the sentence "Hydra palys a very different game to any other computer >>>>that I ever saw" leaves me a bit out in the cold. >>>> >>>>regrads >>>>Andy >>> >>> >>>It's a little hyperbole and a lot of exaggeration. :) I had crafty analyzing >>>most of the games live on ICC and it as well as most other programs predicted >>>Hydras moves _very_ accurately... >> >>Please define "_very_ accurately". 100% of the time? :-) Or are you running >>Crafty (or pehaps a stable of engines) and noticing that the engine(s), at some >>depth or another, show the same move as Hydra most of the time. How often did >>Crafty come up with the same move as Hydra when given the exact same amount of >>thinking time? I haven't tested this, but I'll bet it is less than 95%. > >In one game where I kept the log, Crafty got 36 of 37 moves right (it keeps up >with this in the log file). Crafty was searching as moves were relayed on ICC, >so I have no idea how the moves were relayed there with respect to real-time at >the game site. > > >> >>And even if Crafty did predict Adams' moves (once out of book) perhaps as much >>as 95% of the time, even that does not mean that Hydra didn't put much more >>pressure on Adams than Crafty or other PC engines would have. At the highest >>levels of chess it only takes a move or two per game to make a big difference. >>One slip by the computer and the presure is off. More presure->"very different >>game" (at least from a subjective human perspective such as Adams') even if all >>the other moves would have been the same. >> > Of course a hardware node is not like a software node. However there is little room for doubt on their nps. Where deep blue had just a few weeks to get 480 chessprocessors to work, and where they were crashing the first game already 2 times (others mention even they crashed 3 times the first game, i just noticed 2 crashes; note none of them show in the logfile). Now it's very unclear how long it took in deep blue to get majority of ASICs going. I guess majority never got a job. In Hydra thigns are different. First of all it's just 32 fpga cards in a 32 node dual machine (64 software processors). So way easier to put all processors to work at a time control of like 2 hours a game or slower. Hydra has been tested very well. It plays every day, operated by sheik in own person, at the fritz server. First he just played 60 15, and when hydra scaled better, also at faster time controls he dares to play with it now. I have some remarks done by Chrilly here that he needs 6 cycles per node. So 1 fpga chessprocessor can do in theory up to 10 million nps. So the theoretic peek of it is around 320 mln nps. Getting 32 cpu's to work is real simple. I had zero problems with it either. However i guess he loses a lot to the memory controllers and the fact that at fast time controls it's hard to keep all 32 busy. From my experience i know that the speedup from 32 is not that much better than it is from 16 cpu's. The move to 64 cpu's also hardly gives much extra speedup. The problems of keeping all cpu's busy, meanwhile maintaining a good branching factor start above 100 cpu's. As we know the plan is to create a 1024 processor hydra monster. So there is still a lot of improvements needed in their search algorithms. Like with all machines and programs, deep blue, hydra, and version Y from program X, some months later there will be a new software program that's better, when run on a parallel machine. I'm not so sure Hydra would win world champs 2005. Yet in 2005 it has a good chance, world champs 2006 it for sure won't win. The nps it can achieve however is out of question and very constant. Middlegame or endgame. The huge advantages of hydra over deep blue are several. First of all a REAL chessprogrammer has made the machine in FPGA logics. Deep Blue was created with XOR, AND and such signal blocks. Hydra is in that respect still 'understandable' as it has been written in a low level language. It hasn't been written in the utmost low level. So hydra is maintainable, in contradiction to deep blue. Secondly, hydra is doing very tiny searches in hardware. Mostly 2 ply. Sometimes 3 ply. They search just like 50 nodes or so at most. Searching in hardware is very inefficient as we know. Hydra is doing majority in software simply. Third and this is most important, they daily test the machine. There would be no room for a deepblue project now, its testing was year 80s standards. Hydra is well tested and plays daily. It is having no real weak spots other than that it may never lose a match, which the sheikh's money garantuees never will happen. Humans have a severe weakness which hydra doesn't have. It's called money. >My point was that Hydra is most _certainly_ not some new level of computer chess >as stated by Adams. I wouldn't argue against it being the best computer chess >entity at the moment. But it is absolutely _not_ head and shoulders above >others. The advantage I have is that I have a lot of experience with parallel >and distributed search, and know the losses that a distributed search entails >compared to a pure SMP approach. And even if they are currently reaching 200M >nodes per second, which I somehow doubt given the FPGA numbers they have >published in the past, that is not _that_ much faster than other readily >available hardware. I've seen numbers well beyond 20M for Crafty on a quad >dual-core opteron, for example. I've seen numbers more than double that on >other machines I can't really mention at the moment. So they are not _that_ far >beyond today's programs. Clearly Adam's comments are based on some other >reality or understanding that is not based on factual analysis. > > > > > > >>Then there is also the issue of opening books. Hydra leaves book faster than >>most top programs, because the Hydra team believes Hydra handles being out of >>book and finding good TN's better than other programs. Leaving book earlier is >>already, all by itself, a radically different game, in spite of how many of >>Hydra's subsequent moves the PC's might find. > >Many programs have done this. All the way back to the 1970's. It is not a new >idea at all. Many use very selective books for such matches also. And it has >its dangers if the human chooses to attack such a book. Too many lines that >appear to win a pawn to a 15 ply search, but 25 ply searches would show that the >pawn was poisoned... That is a _huge_ risk for those willing to take it on by >playing to a book weakness... > > > > >> >>I am certain Adams has played many games against PC engines. I am certain Hydra >>seemed subjectively, to Adams, as stronger and harder to handle than these PC >>programs. This means that Adams statement "Hydra plays a very different game" >>would, from Adams' perspective, be completely true; even though PC's can predict >>most of Hydra's moves. > > >I simply believe it is hyperbole. I know too many GM players that both watched >the games, and have played thousands of games against computers, and they simply >said "it played pretty good chess, very good tactically, less good >strategically, and the opponent simply played the wrong style of chess to beat >the machine." I had too much exposure to deep blue, and saw the exact same >thing back in the deep thought and deep blue days. OK strategic chess, >excellent tactical chess, no giant breakthrough at all... Just a big >computational edge. In 1996 DB's edge was 100X faster than the micros of the >day. Today Hydra's edge is not even 4x. 4x is significant, but not >unbeatable... > > > > > > >> >>I think your claim above regarding Adams could be a little hyperbole and a lot >>of exaggeration. :) >> >>-Robin > > >Think what you want. If Hydra blows through the WCCC undefeated, your point >might have a chance. I doubt it will...
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