A great look at the Kansas City Chiefs running a counter and using the FB to wrap on the play side linebacker. They run this against an under front, doubling the 5 technique. You need movement and then come off to the backside linebacker. On this particular play (and this happens on counters), the play side linebacker steps opposite and then tries to come underneath and get to the runner. The guard does his job and protects that gap, blocking him even though he is not the back side LB. The counter action will help slow linebacker pursuit. You also need a physical kick block. Center fills on back side 3 technique. Once you have established the counter, the play action can be deadly off the counter action.