Team D/ST Point category for WIN
Bonus points for a team D/ST who won. 1% or something, or variable. This ensures that the winning team is more likely to outscore the losing team.
So, when one NFL game ends 45-38 and another NFL game ends 10-7,
you want to reward the DEF that allowed 38 points.
The DEF which allowed 10 points to be scored plainly did its job better.