When comparing a defense to an offense, how would you go about assigning a numerical value to position players that appear should dominate his opponent?

Eg...team A has a great running back, likes to run over left tackle and averages 6y/carry when doing so. Team B has a horrible left tackle which allows the same 6y average when ran over.
How would you you use this information? I am just not sure how to use this when determining which side to bet ATS.

Hope this makes sense...