Why You Coach Run Fits, Not Gap Responsibility

The term ‘Run Fits’ gets thrown around a lot. It’s not exactly clear to everyone what it means.

It’s probably the toughest term to explain. Hardest for new coaches to grasp, too – maybe because there’s so many bad explanations out there.

Many coaches keep it too simple when they talk run fits. They only talk about gap assignment.

I’m all about the K.I.S.S. philosophy when we’re talking to our players. As a coach, though, you need to know some detail.

In my very first year as a Defensive Coordinator, we took on the leading rusher in the region. Our team was running a 3-3-5 Defense with a pattern match Cover 3 as the base coverage.

The game was a shootout. Our offense stayed step for step for 3 quarters. But we couldn’t keep up for all 48 minutes.

I tried every adjustment I could think of. We played a 4 front. A 5 front. A 6 front. We blitzed like crazy. Blitzed no one. You name it, I called it.

Nothing worked. Why wasn’t it working?

In the film room, it became pretty clear. Their base offensive play was Power. You know… down-down, kick out, wrap to the backer. That old thing.

We were in the right gaps every play. But the wrong side of the gap. Especially the Linebackers.

When Linebackers blitzed, they blitzed wide. And got kicked out. Over and over again.

When I talk about run fits and how the spill players are responsible for the inside half of the gap, that’s what I’m thinking about.

The medical term for thinking about it is probably “flashback”. It happened over and over again (did I mention that?).

When you teach run fits, you have to teach a whole lot more than gap responsibility. Where do they it in relation to the gap? What do your guys do if another blocker shows up in the gap?

I want our spill defenders (that’s your defensive linemen and inside linebackers in most defenses) to scrape paint with the Offensive Lineman to the inside of their gap.

An A-Gap defender is going to fill his gap with his shoulder pad brushing the Center. That forces the running back to go outside.

If a new blocker shows up in his gap – usually a blocking Fullback or a pulling Guard – he’s going to fit inside of him.

Think it through and this is natural. If he’s staying on the inside half of his gap, he must end up inside of a new blocker coming to the gap.

Teaching run fits to your defense is so critical. You run fits should never change. That allows you to defend absolutely any running play.

When planning your defensive scheme, spend more time on defining your run fits in your base front than you do planning elaborate blitzes and multiple coverages. It will pay off for you!

How do you teach your players to fit the run? Leave a comment!