Author: Uri Blass
Date: 18:56:57 04/30/01
Go up one level in this thread
On April 30, 2001 at 21:09:36, Dann Corbit wrote: >On April 30, 2001 at 19:02:27, Uri Blass wrote: > >>On April 30, 2001 at 18:48:55, Robert Hyatt wrote: >> >>>On April 30, 2001 at 18:28:56, John Merlino wrote: >>> >>>>On April 30, 2001 at 15:43:56, Robert Hyatt wrote: >>>> >>>>>On April 30, 2001 at 13:20:33, stuart taylor wrote: >>>>> >>>>>>I feel It's just a bit tooo inconsistent now. First 5 straight wins for DJ, then >>>>>>nothing like it again, and even 3 straight wins for DF. >>>>>>There must be something wrong somewhere! >>>>>>People can say calmly "that's ok! nothing to worry about! It's quite normal!" >>>>>>OR perhaps, chess is really a game of luck!!! >>>>>>OK, if its proven beyond doubt that all this was the way things go, without any >>>>>>imballance or bug because of things like learning, autoplayer etc. that's fine. >>>>>>But I would like to see it investigated fully. >>>>>> Unless it was that the first 5 games were openings which were advantageous to >>>>>>DJ, but having "learned" them, DF was now well protected from these Junior >>>>>>tricks. Could that be the case? >>>>>>S.Taylor >>>>> >>>>> >>>>>Pick any two programs. Play 50 games. You will find at _least_ one place >>>>>where each won 5 games in a row. There is absolutely nothing unusual about >>>>>this. >>>> >>>>Of course, you mean two theoretically equal programs (and do you also assume >>>>that there are no draws?). And, just to test this, I just looked at the results >>>>of a few 100-game matches, and there was only one instance of a program winning >>>>four in a row. There were no five win sequences. There were MANY sequences in >>>>which White won four in a row, though. >>> >>>I was not ignoring draws... and even with two programs that are 100 points >>>different is skill, I have seen the weaker win 5 in a row in a reasonable >>>match... >> >>It is not common Junior was 3 times black in the first 5 games. >> >>If you assume 30% chances for black to win and 40% chances for white to win >>you get probability of less than 0.5% for Junior to win the first 5 games. >> >>The probability that one of the program wins games 1-5 is >>0.4^2*0.3^3+0.4^3*0.3^2=0.00432+0.00576=0.0108 >>The probability that one of the programs win games 2-6 is also 0.0108 >>... >>The probability that one of the programs win games 46-50 is also 0.0108 >> >>Conclusion: >>The probability of the union of these 46 events is less than 0.0108*46 >>It means that the probability to get 5 wins in a row for one side if you play 50 >>games is less than 50%. > >I think the model is probably flawed a bit. I have seen some really strange >sequences with chess programs. Especailly learning throws a monkey wrench into >the model, since the events are not *really* independent. There are other possible reasons for strange results. One machine may be slowed down by a significant factor in part of the games. This is the reason that the programmers gave the number of nodes per second after every move in their logfiles. I suggested this idea in the past after finding a case when it happened in the ssdf games. It may happen in some games in a row so it may explain strange results but in this case the nps prove that this is not the problem. > >I wonder if the machines were swapped again after each set of 5 games. One >machine being peculiarly better would explain the outcome to some degree if it >was switched at game 5 and stayed there. Enrique checked and found that there is not more than 0.2% difference between the machines so I do not believe that it is the problem. I think that better opening preperation of the junior team can explain the result better. It is possible that the Junior team planned some opening that Fritz does not understand and it worked in the first games. Uri
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.