The key element to the O’Brien is understanding it is a run first offense. This is not to say you can’t have balance; however, the pass will be most effective when the defense has to commit 5 defenders to the run game. In most sixman defensive alignments, four players have run assignments pre-snap and two have pass reads. The goal is to make all six defenders think run and this is done through the blocking on both run and pass plays.
The run game starts with the base Gap On Down (or GOD) blocking assignments. Every player on the line is responsible for their gap. The center has either the LDE or the LCB/LLB. He is instructed to deny anyone that lines up in front of him or to the left a clear path down the LOS. If the LDE is more read and react then he is to block to the second level where he might pick up a blitzing CB or LB which starts outside his left shoulder. (Figure 1)
The Inside Receiver (IR) is instructed to block anyone who lines up in the A gap. His technique is more like a pass block on most plays as he too is not concerned about penetration up the field as he is down the LOS. He needs to be instructed as well not to allow the defender to come across his face into the B gap. (Figure 2) On the occasion where he has a defender “On” (in front of) him and a defender either lining up in the A gap or blitzing the A gap his responsibility is the defender in the gap. The On defender will be blocked by either the OR or the FB. This is a very difficult concept to teach and must be repped many times.
The Outside Reciever (OR) is instructed to block the B gap if a defender either lines up in the gap or blitzes the gap. He will often have a LB in gap (as opposed to a defensive lineman) and there is often a backside LB as well. If teams blitz the backside LB at the snap (or on a delay) his responsibility will be the backside LB. When the blitzing backside LB delays, the OR will take his first step toward the LB in the B gap and possibly engage but will shift to the blitzing backside LB if needed. (Figure 3)
To offset aggressive defenses like a 4-2 (which is the same as a blitzing 3-3-) or even a 5-1, the FB is moved to the Hammer position where he will work with the OR to defend the gap and kick out or hook the DE. (Figure 4) From the Hammer position, the FB will make the line call to either have both the OR and FB block down or the call for the OR to block down (toward the gap) and the FB to block out on the DE. It is rare for both players to block down because it is rare for the DE to line up On the DE or FB. It is even rarer for the DE to widen out so far as to take themselves out of the play where the Q would have time to make the block.
The QB is usually one of our best blockers and is certainly someone who likes to take people to the wood shed! Think more Tim Tebow than Tom Brady. He has NO pre-snap blocking assignment. His job is to take the unblocked man and lead the RB through the hole. This means he has to make the decision for the RB as to which hole they will be running through. This is very important. It is not the responsibility of the RB to make the first up-field cut. The RB is to catch the pitch and then try to get his hand on the back of the QB at the LOS. To do this effectively, the QB must not watch his pitch be caught by the RB. He must pitch and get his head around to read the blocks of the IR, OR and FB. He will then either take a path inside the DE or outside the DE depending upon the blocking. When he gets to the second level he will either be kicking out the second level defender or hooking him inside. (Figure 5a and 5b)
Defenses will often focus on the FB as the belief is the direction he blocks is the direction the play will be run. To counter this the blocking will be altered to have the FB block the A gap while the IR pulls to block the DE. (Figure 6)
Another change is to Hammer the FB and then counter to the opposite side of the defensive with the IR or OR pulling to block the DE depending upon a three or four man defensive front. (Figure 7) As you can see, the center is utilized to trap block on the counters and reverses where he picks up the defender in the A gap or a LB if the A gap defender does not penetrate but moves down the LOS.
We have also been known to pull both the IR and OR on a reverse to the FB but this is only effective against teams who line up 5 defenders at or beyond the A gap (Figure 8).
There are only two types of pass blocking and they differ depending upon the starting location of the passer. If the QB is to become the passer (which takes away his ability to run) then the RB and the FB become the passer and are instructed to take A and B gap pressure. (Figure 9)
If the RB or the FB become the passer (which requires a pitch) then we effectively have a Diamond spread formation where the other two backs become the blockers for the passer. (Figure 10) We will keep one of the lineman in on a pass play for extra protection if needed and this is almost always the IR to block the A gap which leaves the RB with the B gap and the FB with the DE (Figure 11)