Who Blocks Whom? A Tutorial
When the center gets to the LOS, you always see him pointing at somebody, right? Who? He’s pointing at the defender who has playside A gap responsibility, what Chip calls the “0 (as in zero) defender.” He might be a down lineman, an LB, or a safety who has walked up. Regardless, it's up to the center to recognize who that guy is and point him out. Based on that, the O linemen count. The next guy out, whether DL or LB is #1, the next guy is #2, and so on.
In the shot above, the defender with backside A gap responsibility may be either #96 or #59, whom Washington has stacked behind the DT to (a) protect him and (b) confuse the blocking assignments. It's up to the O linemen to figure out who blocks whom and communicate that. We'll get to it.
In the IZ, the O Linemen block from the inside out.
In simplest terms, if you’re covered, block the guy covering you. If you’re not, go help the next guy to the playside. If, for example, the LT is covered and the LG is not, the LG will double the man over the LT. He will not double the guy over the center. Well, almost never. You block toward the playside when zone blocking.
Even though Mathis (69) is in an excellent position to help Kelce with the DT (the "0" defender) in the A gap, he (Mathis) is not covered and will follow the rule and block to the playside, which is to the left. He blocks the "1" defender. All the other OL block to the playside as well.
Part, but only part, of the rationale here is that you want to get the DL moving laterally. (More on this later.) The more they move laterally, the less power they have and the more options the RB will have regarding cutbacks and the like. In fact, if the DL wants to move laterally, it’s your job to encourage him. In this regard, zone blocking is all about angles. The OL are moving diagonally and are trying to sweep the DL with them. This is an essential difference between drive blocking and zone blocking. Much of drive blocking is straight ahead, man-on-man stuff. The called play is off-tackle, you block off-tackle and the RB hits the hole off-tackle.
By contrast, zone blocking is about angles. Not to introduce an element of confusion here, but in the IZ, if you’re covered, you’re blocking that guy, period; you are, thusly, drive blocking. It doesn’t matter where the playside or backside is; you’re blocking that guy and it doesn’t matter whether you’ll get help or not; you’re blocking that guy.
In simplest terms: Block to the playside.
In the other example:
Counting from the inside out, Kelce blocks the "0" defender (the man with playside A gap responsibility), Mathis blocks the "1", and Celek blocks the "2". Herremans has no one covering him so he blocks the nearest man to the playside, i.e. the NT. This is a double-team and there will be much more on this later. Peters blocks the DE on his inside (playside) shoulder.