Author: Omid David Tabibi
Date: 14:47:43 07/14/04
Go up one level in this thread
On July 14, 2004 at 17:38:45, Sean Empey wrote: >On July 14, 2004 at 17:15:52, Omid David Tabibi wrote: > >>On July 14, 2004 at 17:10:13, Matthew Hull wrote: >> >>>On July 14, 2004 at 17:03:33, Omid David Tabibi wrote: >>> >>>>On July 14, 2004 at 17:00:04, Matthew Hull wrote: >>>> >>>>>On July 14, 2004 at 16:53:39, Omid David Tabibi wrote: >>>>> >>>>>>On July 14, 2004 at 16:44:00, Peter Berger wrote: >>>>>> >>>>>>>On July 14, 2004 at 12:56:10, Omid David Tabibi wrote: >>>>>>> >>>>>>>>On July 14, 2004 at 12:34:18, Peter Berger wrote: >>>>>>>> >>>>>>>>>On July 14, 2004 at 12:28:29, Omid David Tabibi wrote: >>>>>>>>> >>>>>>>>>>On July 14, 2004 at 12:19:24, Peter Berger wrote: >>>>>>>>>> >>>>>>>>>>>On July 14, 2004 at 11:41:04, Omid David Tabibi wrote: >>>>>>>>>>> >>>>>>>>>>>>On July 14, 2004 at 11:38:31, Peter Berger wrote: >>>>>>>>>>>> >>>>>>>>>>>>>On July 14, 2004 at 11:26:47, Omid David Tabibi wrote: >>>>>>>>>>>>> >>>>>>>>>>>>>>On July 14, 2004 at 11:12:14, Fernando Villegas wrote: >>>>>>>>>>>>>> >>>>>>>>>>>>>>>Not at all, Omid >>>>>>>>>>>>>>>If you already have a parallel engine you should run it into a >>>>>hardware capable >>>>>>>>>>of getting all its power. >>>>>>>>>>>>>> >>>>>>>>>>>>>>I understand that you are going to provide the hardware, right? >>>>>>>>>>>>>> >>>>>>>>>>>>>>It is not something personal; next year I will have the needed >>>>>hardware, but >>>>>>>>>what about others? Deep Sjeng and ParSOS were also >>>>>parallel engines, but ran on >>>>>>>>>single processor not because they >>>thought >>it was better, but because they did >>>>>>>>>not have access to a >>>fast >>multiprocessor machine. >>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>>I wonder what except the results changed from two weeks ago to now to >>>>>make you >>>>>>>>imply this is an unfair event and go on raving about it ?! >>>>>>>>>>>>> >>>>>>>>>>>>>Weren't you even one of the organizers? >>>>>>>>>>>> >>>>>>>>>>>>Yes, and I complained loudly about it even before the event. >>>>>>>>>>> >>>>>>>>>>>Actually I still think this is argueing with hindsight. Diep and Crafty >>>>>finished >>>>>>3rd and 4th, a result that surprised some of the present >>>>>programmers. >>>>>> >>>>>>>>>>>It seemed to concern no one last year when it was only the >>>professionals >>who >>>>>>came with superior hardware. >>>>>>>>>>> >>>>>>>>>>>To quote another programmer from memory: "I typically get 80% in tests >>>>>against >>>>>>Crafty, so on a Quad it might get 30% or sth like that ". >>>>>>>>>>> >>>>>>>>>>>And we don't know how the results would have looked like in a single >>>CPU >>event >>>>>>either - before the tournament it was "Crafty is a miserable >>>>>program that I can >>>>>>beat on any hardware" (simplified and no quote) - >>>>>>>>>> >>>>>>>>>>This quote is not from me. >>>>>>>>> >>>>>>>>>And I didn't imply any different. >>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>>>at least one part of this >>>>>>>>>>>statement turned out to be untrue. >>>>>>>>>>> >>>>>>>>>>>Maybe the hardware impact is a little overrated in this discussion >>>>>anyway. Jonny >>>>>>on a PIV2.8 e.g. nearly finished Junior on a Quad. >>>>>>>>>> >>>>>>>>>>You want to measure the hardware impact, just do the following: >>>>>>>>>> >>>>>>>>>>Run the Crafty benchmark at a fast single processor machine, and also on >>>>>the >>>>>quad machine: >>>>>>>>>> >>>>>>>>>>ratio = (benchmark on quad) / (benchmark on single proc) >>>>>>>>>> >>>>>>>>>>(the ratio would be about 4) >>>>>>>>>> >>>>>>>>>>Next, for each move of Crafty in the tournament, divide the thinking >>>time >>by the >>>>>'ratio' above, to get a new time: >>>>>>>>>> >>>>>>>>>>time2 = (original time spent on the move) / ratio >>>>>>>>>> >>>>>>>>>>Now just count how many times Crafty changed its PV after 'time2'... (In >>>>>other >>>>>words, how many times Crafty changed its PV after thinking for 1/4 >>>>>of the time >>>>>on the move.) >>>>>>>>> >>>>>>>>>This test sounds more scientific and logical than it is. You also would >>>>>have to >>>>identify the moves that would make any difference to the result >>>of >>the game. >>>> >>>>>>>>>I can easily reproduce all critical moves of the Falcon-Crafty game on my >>>>>>>>>notebook for black. I already asked you in another message if more time >>>>>would >>>>have made any difference for Falcon for two of its critical >>>mistakes >>- you >>>>didn't answer yet. >>>>>>>> >>>>>>>>Just count the number of times Crafty changed the PV after 1/4 of its >>>>>thinking >>>time (including pondering), and see how many of them were >>>critical, >>and >>>prevented a loss. >>>>>>>> >>>>>>>>You will find many of them. Here is one I remember clearly: After Falcon's >>>>>>>>...Ra5 in the endgame, Crafty wanted to repeat the position at first >>>(score: >>>>>0.00). It thought for a long time, and then changed the PV to >>>other move, >>which >>>was winning. But you will find many other moves in the >>>earlier stage >>of the >>>game, which would have resulted in a loss were they >>>played (after >>thinking for >>>1/4 of the time). >>>>>>> >>>>>>>I think you maybe misunderstood me here because of the heat of the >>>>>discussion. >>That I can easily reproduce Crafty's moves on my notebook >>>doesn't >>mean that all >>its moves were found fast and easily :). >>>>>>> >>>>>>>From memory there were two moves in the tournament where Crafty changed its >>>>>mind >>very late and that turned out to be of big importance. >>>>>>> >>>>>>>Kb6 (or whatever the move after Falcon's Ra5, no surprise that we both >>>>>remember >>this one) >>>>>> >>>>>>OK, so at least you agree that without the 4x hardware advantage Crafty >>>>>wouldn't >have got more than a draw. >>>>>> >>>>>> >>>>>>> and g5 in the game against Diep. >>>>>>> >>>>>>>In case there were other moves like that, I am at least not aware of it. >>>>>>> >>>>>>>I expect Bob to offer Crafty's logfiles for download soon as he did for >>>>>cct-6, >>so maybe we should delay this discussion until we can just discuss >>>the >>real data >>( I don't have access to the Opteron anymore). >>>>>>> >>>>>>>I would still be interested to know about the critical points from >>>Falcon's >>>>side; Ra5 is a trial to avoid repetition - you have to search very >>>deep to >>>>dismiss it. >>>>>> >>>>>>One iteration deeper Falcon switches to the other move which results in >>>actual >>>threefold repetition. >>>>>> >>>>>>In other words, had Crafty not had the hardware advantage it would have >>>missed >>>the win, and had Falcon had the 4x hardware it would have found the >>>correct >>draw >(and with that hardware advantage probably also found a correct >>>winning >>line). >Right? >>>>> >>>>> >>>>> >>>>>Why don't you just test it. Download crafty19.15 and setup the appropriate >>>>>time controls for each side and start from some move in the actual game. >>>>> >>>>> >>>>>Then we won't be in fantasy land anymore, but in the land of fact. >>>> >>>>It is not fantasy. During the actual game Crafty found the correct move in the >>>>endgame after a very long search (previous best move was threefold >>>repetition). >Peter was the operator, and has said the same in the post above. >>>Quoting him: > >>>>"From memory there were two moves in the tournament where Crafty changed its >>>>mind very late and that turned out to be of big importance. Kb6 (or whatever >>>the >move after Falcon's Ra5, no surprise that we both remember this one)" >>> >>> >>>No, I meant that Falcon could find _winning_ lines, not just drawing lines. >> >>I will try the game to see if there was a clear winning line. But it is clear >>that on equal hardware white would not have lost the game. > >That's not clear until you can also prove Crafty would not have found that move >on a single processor. And Falcon could actually win the game. You need data to >back that claim up. Why don't you read other posts in the thread before asking a question already discussed elsewhere? See for example the discussion between Peter Berger (operator of Crafty) and me: http://talkchess.com/forums/1/message.html?376835 http://talkchess.com/forums/1/message.html?376837 http://talkchess.com/forums/1/message.html?376846 > >-Sean > >> >> >> >>>Remember that Boris said many times that the game was over in favor of white. >>>So white should have won. Give Falcon equal time as crafty, and long time to >>>simulate 4x opterons. >>> >>>Then we should know if you would really have won that game with equal hardware. >>> >>> >>>The other experiment is to substitute Junior for Falcon on the slow hardware >>>setup and see if Junior also cannot win on uniprocessor. >>> >>>> >>>> >>>>> >>>>> >>>>>:) >>>>> >>>>> >>>>> >>>>>> >>>>>> >>>>>> >>>>>>>And Ra8 is probably not about search at all. >>>>>>> >>>>>>>Peter
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