The last group of run-game-specific pulls I want to cover are related to the Trap play, bootlegs/waggle passes and screens. A trap play is one where at least one DL is intentionally unblocked by the lineman across from him, only to be nailed by another OL coming from the other side. He thinks he is free to jump into the backfield only to get "trapped" by someone he wasn't expecting. Traps are quick-hitting plays that use a little deception to get yards instead of the brute-force downhill running. Its my belief that any spread formation offense needs to be able to run a trap well because they usually aren't going to be able to outnumber a defensive front in the box and create extra gaps to defend.
A trap pull is usually used to describe a quick pull from the backside to playside of a formation, but can also be a totally-onside G-block. The backside trapper going from the left to right pushes hard off his left foot and his down fingertips, then jerks his inside elbow back to force his hips open. This pivot turn is called a handshake move, because it will look like he's offering his right hand. His inside foot should be pointed in the same direction as that handshake.
Backside OT running a long trap is more like a sweep pull than a trap pull, tackles only execute long traps.
Typical quick inside trap
The distance or length of the trap dictates how far he opens his shoulders. When a LG is trapping a right-side 3-technique, he wouldn't open them as far as he would to trap a 5 or 6-technique, for example. A long trap is executed just like a long sweep pull, and can become a kick-out block. Actually all traps can be thought of as kick-out blocks, they just don't need to be on the edge of the formation like a normal kick-out. The RB reads the block in front of him and on an inside trap he should be following the trapper.
The quick way of teaching the trap is "pull left -- hit left" or "pull right -- hit right". This means when he is pulling to the left, he makes contact with his left shoulder. If he pulls to the right, as above, he initiates contact with his right shoulder. This way of teaching it makes no changes for the action of the defensive lineman, i.e., whether he's a reading defender or a penetrator, but that adaptation can be done. A penetrating lineman should be caught by everything described so far, and kicked out of a hole.
When the defensive line is a read-and-reacting type, the trapper can read the movement of the defender down the line of scrimmage and convert his block to a Log block, and try to spin the defender and seal off the inside. The major problem with this method is just that it can lead to cloudy minds and slow feet in a game, and this play is meant to be quick-hitter.
The G-block is just an outside trap by the playside guard, and is vicious against DEs who are wary of outside blockers. Therefore, its good to run against a 5-7 technique DE who has an OT head-up/inside and a TE on his outside shoulder. That DE will always be wary of what the TE is about to do to him, and its that waryness that opens him up to a trap from the inside. Once he sees the Tackle down-block, he's going to look to his left and prepare himself for the TE to down-block on him. In that split-second the OG should catch him and blindside him.
Onside G-block on a 6-technique (forgive misplacement of the QB)
Instead of using a line TE to fool the DE, the same thing can be done with an H-back. I would call that type an Influence trap we covered before. The H is set up outside and slightly behind the OT, and his initial move is a hard push to the outside hip of the DE. At the last second he cuts back outside or upfield to engage an OLB or SS, and the G-block should take out the End.
Below shows one way we, and Oregon, would run the trap.
Pulling around the Horn
An alternative to the outside zone or combo block becomes evident against certain defensive fronts where a DL blocks the path of an OL to take out a LB. The horn block is one normally used in outside plays where the 4i-technique is blocking the path of the Guard to hit a LB.
The situation where the G would make a "horn" line call. You can see the 4i prevents him from taking a direct line to the LB he's assigned to take out. Zone schemes would double the 4 and one make breaks off to hit the LB.
If the LB is reading the flow of the RBs, then he may quickly begin scraping outside and behind the DL, called "going over the top". The 4i here is meant to absorb two blockers, and is almost always playing a read technique. A horn block involves the OT trying to down-block the 4i, while the Guard "steps around the horn" behind the OT and comes right into the facemask of the scraper.
When he pushes off with his inside foot, the Guard needs to keep his shoulders as parallel as possible to the LOS and read the movement of the LB. He seals the LB by engaging from the outside-in and the RB should follow behind towards the sidelines. In a way, this is just like the fold-block.
Recall in the Zone/combo, the two OL work together to generate an initial push and then one man breaks off the defender once they generate movement. In theory, that should be easier, but its more difficult to execute because most defenses adjust their fronts and stunt so well. Zone blocks have to be repped endlessly to run them well, and the horn pull is just simpler.
In the Horn play below, it is the Tackle pulling around the horn to take out the OLB.
Quick Screen Pulls
Clemson used to use this much more before Chad Morris arrived, and its an outside pull by the playside G or T to set up a slip screen. Quick screens like this involve the WR taking two steps and then pivoting back and running around behind the LOS to catch the ball. The rest of the linemen are fan blocking for the screen as well, but this pull is meant to spring him free.
In a slip screen pull, the OT (or G) sprints outside and to a point 2 yards ahead of the line, and basically executes a fan block on the CB. If the WR has sold his movment properly, he'll bring the Cornerback right into the OT, sealing off the first defender outside. Since the pass is a screen, the WR should loop around behind him and behind the LOS, so theres no problem with being illegally downfield.
Just one example of a possible quick screen pull. The QB hits the WR behind the LOS and his movement back should draw the CB close enough to be blocked.