Correlated Gaussian Method

PPG Winners = 106.0
PPG Losers = 95.2
Variance PPG Winners = 10.4*10.4
Variance PPG Losers = 10.1*10.1
Covariance PPG Winners & PPG Losers = 74.1

Formula:

                                        (106.0 - 95.2)
0.915=Norm{-----------------------------------------------}
                               [(10.4)^2+(10.1)^2-2*(74.1)]

from

                                                             (106.0 - 95.2)
Expected Win%=Norm{------------------------------------------------------------------}
                                       [Var(PPG)+Var(Opp. PPG)-2*Cov(PPG, Opp. PPG)]


where Norm{} means finding the percentile of the standard Normal
distribution with mean=0 and variance=1 corresponding to the
quantity in {}, PPG is points per game scored, Opp. PPG is points per
game allowed, Rtg is the offensive rating, Def. Rtg is the defensive 
rating, Var() is the variance (from game to game) of the quantity in 
(), and Cov() is the covariance of the quantities in ().