Part of this is fairly simple. Mike Cox has blown more than one block in the ground game thus far in pre-season, while I haven't seen Polite screw anything up too badly. Polite has also proven he can catch the ball out of the backfield, a valuable talent for a fullback in this offense.
The absence of Bradie Ewing has obviously screwed up the team's plans a little bit, because neither Cox nor Polite have the power-blocking potential of Ewing. But the Falcons have to make the best of it now that he's gone for the season, and right now, it looks like Polite is nudging ahead.
Look for both fullbacks to get some run with the first time this week versus the Dolphins. Another good week from Polite may help him seal up the job.
Who do you think wins this battle?