There's something inherently confusing about the idea of the "pocket" in football. It goes back to the first time you watched the sport as a kid, and wondered why the running back ran directly into the mass of humanity directly in front on him, not around it. The defensive line is supposed to be something to avoid, you assume, not something you attack.
And quarterbacks who struggle with the pocket -- and I can admit I was terrible in this area early in my career -- have a similar sense of confusion, even with an advanced knowledge of the game. A rookie like Blaine Gabbert isn't yet used to the idea that amid that cluster is where you gain your greatest advantage as a passer. He backs up, he moves to the sides, he sees the surrounding pressure as a limitation.
But it's the opposite.
Think about this at the most basic level. For one, it's a matter of opportunity. The passing width of a football field is a hair over 53 yards, and a defense has to cover that area with six or seven guys in the secondary. Sometimes fewer. Then factor in the 50-plus yards of depth down the field a quarterback can reach. It's a huge area for defenders to cover, 50 yards wide and 50 deep -- at least if the passer stays in the pocket. There, within a few yards of the line of scrimmage, in that central location, he can reach it all. Run to the side, and suddenly the same six or seven defenders must cover closer to half the space horizontally. Step farther back, and the field shrinks vertically. You may feel open, but the options are cut in half and the pass defense is more concentrated.
Secondly, it's a matter of maximizing blocking. The pocket is the place an offensive lineman knows he must protect. He can move back and absorb pressure. It's not just a quarterback's area to work, it's a blocker's area to protect. Leave it prematurely and you waste not just your optimal passing zone, but you diminish the goal of the blocking. Ask any lineman: Nothing annoys him more than a quarterback who ditches a well-blocked zone at the first sign of pressure.
So what creates that proverbial "pocket presence?" For starters, it's not a "presence" at all.