EXPLANATORY NOTES - NATIONAL RATING SYSTEM
The system now uses a slightly modified version of the
Glicko rating system which was designed by Professor
Mark Glickman who is Chairman of the USCF Rating Committee. The main difference
between the Glicko system and the Elo
system is that it introduces the concept of a RD or Rating Deviation which is
effectively a measure of how accurate is the players rating. Some info on the Glicko system it is available at http://math.bu.edu/people/mg/ratings.html
The Glicko system is used on the FICS (Free Internet
Chess Server) and elsewhere.
For
the December 2009 rating period there were 129
Tournaments rated (93 Classic, 36 Rapid) and 9333 games
of which 5976 were in the ACF Classic rating system and
3357 were in the ACF Rapid rating system.
The ACF active list now shows the players active
A rating is followed by either a !!,
a !, a blank, a ?, a ?? or a g.
A !! indicates a very reliable rating.
A ! indicates a reliable rating.
A blank indicates the rating is neither
reliable or unreliable. Its just a rating.
A ? indicates the rating is unreliable.
A ?? indicates the rating is very unreliable.
A g following a number indicates the player needs that
many more games before he will get a rating.