US Squash Rating System
Players of relatively equal skill have their ratings adjusted by a moderate amount when they play each other.

The math behind the algorithm is as follows:
WRO = Winner's old rating
LRO = Loser's old rating
K = constant = .1
D = denominator = .5
PW = Probability that the winner would win = (1/(POWER(10,(-(WRO-LRO)/D))+1))
PL = Probability that the loser would win = (1/(POWER(10,(-(LRO-WRO)/D))+1))
WRN = Winner's new rating = (WRO+K*(1-PW))
LRN = Loser's new rating = (LRO+K*(0-PL))
Old RatingNew Rating
Winner's old rating:
Loser's old rating: