also: run fits · fitting the run · fit
On defense, who owns which gap once the blocks show. On offense, the position your body is in when you make contact. One syllable, two unrelated things.
2 meanings, all below. Jump to the one you heard.
The defensive assignment of every defender to a gap, an edge, or a space, resolved after the blocking scheme declares itself rather than before the snap. A defense is fit correctly when there is a body for every gap and nobody has doubled up, and most long runs are a fit failure rather than a missed tackle.
run fits, gap responsibilitythe offensive fit, run blitzOn offense, the fit is the body position at the point of contact: pad level, hand placement, hips, feet. Coaches fit players up before a drill, walking them into the finished position before running it at speed.
fit position, fitting uprun fitsBoth senses are taught from youth football up, which is exactly why the collision is worth writing: a young coach hears both in his first season, from different people, in the same week.