There are some route-running things here we could get into. Keep in mind that DBs are trained to focus their eyes between the bottom of the numbers and the top of the hips because that is the receiver's center of gravity and thus is the best indicator of where the rest of his body is going to go. It's the reason basketball defenders are taught to focus on the same area, and the reason why the special sauce in a crossover isn't the dribble itself but the change of direction of the hips. Really, football itself, and any athletic movement, really, is all about the hips. The more strength/quickness/fluidity/elasticity an athlete has in his hips, the faster he can shift the energy and momentum of those hips. If your hips change direction faster than the guy who is covering you, you're already a step ahead of him. Watch Agholor's number as he makes his first move. He doesn't do a great job of selling the fake. He steps backwards with his inside foot but his hips barely move. Also, look at the angle of his upper half. It's nearly upright. From a biomechanical standpoint, he isn't maximizing his momentum. Instead of keeping his energy concentrated in his core, he's creating a clotheslining effect on himself. Again, in virtually any sport, the ready position has the upper body at about 45 degrees with the ground, because that's the position that gives you the quickest reaction time. Coming out of that position against a DB is extra inefficient because the DB is looking at your hips, not your upper body (theoretically, at least).