Asri-unix.1106 net.chess utcsrgv!utzoo!decvax!ucbvax!C70:sri-unix!mclure@SRI-UNIX Fri Mar 26 15:13:32 1982 Elo provisional formula I was just glancing through the Elo book and noticed a strange formula used for provisional ratings. 400 ( W - L ) R = R + ------------- p c N Where R = provisional rating p R = average of competition ratings c W = wins (draws count 1/2) L = losses (draws count 1/2) N = number of games played This means that if you are unrated and play the following games Opponent rating your score A) 1200 1 1200 1 1300 1 1350 0 1400 0 B) 1200 1 1200 1 1300 1 2200 0 2200 0 something odd occurs. The only difference between batch A and batch B is that in B your two losses have been to masters rather than 1350 and 1400 players. However the difference between losing to 1350 and 1400 and losing to two masters is great. The resulting ratings are 1370 and 1700 respectively. A 330 point difference. Naturally they will start you out at the lowest class E/unrated and you won't have the advantage of playing against masters. But if you are in league play, as we are in the Bay Area among certain companies, it *really* pays to play against highly rated players while you are in your provisional period (20 or 24 games I think). This seems very peculiar. ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.