Author: Dave Gomboc
Date: 09:17:12 12/24/99
Go up one level in this thread
On December 23, 1999 at 21:01:12, Robert Hyatt wrote: >On December 23, 1999 at 19:30:48, Amir Ban wrote: > >>On December 23, 1999 at 15:05:57, Robert Hyatt wrote: >> >>>On December 23, 1999 at 06:32:32, Graham Laight wrote: >>> >> >>>>In the case of the SSDF computer pool, much of it has been there for a long >>>>time, and is known to be broadly correct. >>> >>> >>>No it isn't, but I also don't have enough time to turn this into a "statistics >>>101 course" and explain why it doesn't work like that. If you look at how the >>>Elo formula works, the _last_ game you played influences your rating _far_ more >>>than the game you played 40 games ago. That is simply how the statistics work >>>here. So even if the original SSDF programs were _perfectly_ calibrated to some >>>human rating scale, the fact that 10 years has elapsed means that the effect of >>>that calibration is _long gone_... >>> >> >>The way SSDF calculate ratings, the order of games and when they were played has >>no consequence at all. They calculate ratings using the entire SSDF game history >>every time. It doesn't matter which game was played last. They would get the >>same ratings in whatever order the matches were played. >> >>When the SSDF calibrated their list, they fixed some reference. Since all their >>ratings are calculated in relative, not absolute terms, this reference, once >>fixed, is relevant forever and can't possibly grow out of date. Had they fixed >>that reference 10 points higher, for example, all ratings today would have been >>exactly 10 points higher, and this will still be true in 10 or 100 years. >> > > >That is _absolutely_ a flawed way of computing ratings of course, and if that >is true, the term "Elo" should _never_ be used in the same breath with "SSDF >ratings". The Elo formula is quite well-defined... and the 'order' is most >definitely imortant in the ratings... It made a lot of sense before programs adapted their play based on experience. It doesn't work so well now, though. Dave
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.