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- Path: sparky!uunet!gatech!udel!gvls1!tredysvr!asns!mdobbins
- From: mdobbins@asns.tredydev.Unisys.COM (Michael Dobbins)
- Newsgroups: rec.games.go
- Subject: Re: Internet Go Server Status.
- Message-ID: <1993Jan25.135217.18606@asns.tredydev.Unisys.COM>
- Date: 25 Jan 93 13:52:17 GMT
- References: <1j728cINNmo2@darkstar.UCSC.EDU> <1jncquINN9h6@terminator.rs.itd.umich.edu> <1993Jan25.104132.575@otago.ac.nz>
- Organization: Unisys Corporation, Tredyffrin, PA
- Lines: 28
-
- In article <1993Jan25.104132.575@otago.ac.nz> barryp@otago.ac.nz writes:
- >I would say that there is something wrong with the algorithm if a win results
- >in a decrease in your rating.
-
- Actually it is possible for a win to decrease your rating or even a
- loss to increase your rating. The algorithm does not adjust individual
- ratings based on performance. It calculates the best set of ratings for
- the population which would best predict the outcome of the games played.
- This means that the right combination of wins and losses could give a
- rating to an individual which does not look correct with respect to the
- limited scope of game results the individual has at hand.
-
- For example if you only play 3 games and beat 3 different people, but
- these 3 play many games and lose them all; they will have a significant
- drop in rating, as would be expected, but you may also show a loss being
- dragged down by them.
-
- Any rating algorithm will have some anomalies. This algorithm trades
- infrequent occurances of the above situation for a much better rating
- estimate taken as an average over the entire population.
-
-
- >I have a query about deleting a user id to clear ratings. Not long ago the
- >server dropped my account (I don't know why) when I recreated it I discovered
- >that the rating was still there.
-
- I forwarded that theory and have been corrected. The IGS currently keeps
- the rating even if the account is cleared.
-