In containing a mobile QB. This means extremely athletic DBs and LBs. Notice I said containing, not shutting down. Fast QBs will make plays no matter what. Always having the edges lit up limits his options.The idea here is to push somebody like Deshaun up the field, close off the edges and force the quarterback or running back to make a play with much less open field. One of the primary keys here will be for the defensive end or OLB to recognize the play relatively early on. Somebody like Lorenzo Carter, a pass-rushing specialist, cannot be turned up field too much. Instead, he needs to maintain the outside and push the play inside. Having an safety spy the QB helps as well for when he is bootlegging out and tries to dump it off. QBs, no matter how athletic and big, do NOT want to get hit. This is why they take the path out of bounds 99% of the time. Hit them enough early on by taking away the out if bounds path and they become very reticent to turn up field.