brown wasn't a backup. cadillac was the "starter" only by technicality. cadillac ran the majority of the time and came out whenever something needed to be done that brown did better, i.e. catching the ball out of the backfield, splitting out, blocking, etc. brown obviously can carry the ball as well as cadillac, and probably better. if brown started, what would cadillac do? brown would just run and catch and block, and cadillac would only come in when brown needed a breather. it just made more sense from a tactical standpoint for cadillac to "start" over brown. in reality, there was no true starter, they split carries.