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.
A number
of changes have been made to the rating system to better handle improving
players including but not limited to juniors. These changes resulted in a
recalculation of all players ratings for all previous periods from December
2000, prior to the processing of the December 2006 ratings period.
For the June 2008
rating period there were 128 Tournaments rated (91 Classic, 37 Rapid)
and 9735 games of which 6331 were in the ACF Classic rating system and
3404 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