I Need help figuring out a sports formula

OK,I have managed to figure out a few sports formulas,like QB Ratings,winning pct & batting avgs,but there is a formula I cant figure out how to do.It has to do with Standings,its the Games Behind First I need to figure out,what I need for it to work is this

W L PCT GB
(Team 1) 5 - 0 1.000 - -
(Team 2) 4 - 1 .800 1.0
(Team 3) 4 - 2 .667 1.5

Subtract Team 1 losses from Team 2 which equals 1
Subtract Team 2 Wins from Team 1 which equals 1
since both numbers are the same it should stay at 1 or 1.0

Now
Subtract Team 1 losses from Team 3 which equals 2
Subtract Team 3 Wins from Team 1 which equals 1
since both numbers are different I need them added then divided by 2 and it will then come up with 1.5

what formula can I use,which will say if the numbers are equal, that is the answer but if they are different, added them and divide by 2

Nevermind,I got it figured out tried a little spacing between things and it managed to fix the problem

sorry