Well, nice topic, I wasn't as descritive as I could have been. As a former WR, it is easy for me to see why the DB doesn't turn around, and alot of them have been outlined in this trend already.
It depends on the play and situation as to whether the DB can turn his head. If he thinks he has been beaten, it is easier for him to just try to hit the WR as soon as the ball drops in the WRs hands and try to knock the ball out.
But if you turn around and the ball is like right there on the WR, when you look back, you could actually miss seeing the ball and it goes right by your head. In this case, if the WR catches it, your toast.
The better DBs will actually watch the WRs reactions. This is done by looking at the WRs eyes, and when you see his eyes widen or his arms go up, that means the ball is coming and you can turn for the ball. You can only do this if you have that WR covered well.
One thing about this though, it is something that WRs know. The best, for instance Marvin Harrison, has been said to try to prevent this by not reacting til they have to at the last minute. Young WRs have the tendency to really react big time, and if they run a bad pattern, the DB is at an advantage.
The best reason to keep your eyes on the WR is to prevent a bigger play, you can just make the tackle. This is a passive type of D, but it can be effective with a good pass rush.
Looking back can make you a champ or a chump. It is harder than you realize to be running with a big time WR, and find the ball in the air and to actually see path of the ball. This takes time, that you might not have.
As a WR, a DB that likes to look into the backfield or for the ball is easy to make into a chump. That is why you see so many DBs beat on out and ups. They are looking for the ball. If the WR is worth his salt, he will fake looking for the ball, and of course the QB can pump fake. That DB is toast. But if he played the WR instead of looking for the pass, he could prevent a bigger play.
I know what most of you are thinking about though, but there is more to it than that. You are thinking that he should look back on a fly pattern. As the DB, you have to be really sure that it is a fly pattern in order to turn your head. An experienced WR can make you think it is a fly pattern, then cut for a deep out. That WR could look up for the ball, which makes the DB that looks for the ball look up also, and then the WR can cut to the sideline for a deep out. That is a completion on the sideline, and the DB is lost looking for the ball that is now completed behind his back.
Supreme talents can look back at the ball more often, but they have to have an incredible amount of reaction and recovery speed. Deion could look back, cause he knew he could recover. But if you are trying to find the ball in the air as a DB, you will lose contact with the WR unless you are really talented and fast.
There is alot to this subject, and it is hard to explain in type. Alot of it is feel in the game. Whatever the DB is doing, the WR is watching. The WR has the advantage, cause he knows what the pattern is and where the ball will be. If a guy constantly looks at every ball, the WR will take note of it, and use it against him. This is the main reason you don't want to look back everytime. Do it everytime, and you will be toast for it with a good WR.
I wish they showed all the patterns of WRs during the game, all of this could be seen. Its too bad that most of this goes unseen until the ball is in the WRs hands. So much happened before the reception, you just can't see it on TV. That is the one thing about this, you can see the OL, QB, RB, whatever. But you can't see the WRs on TV, so as a watcher you can think it is easy to look back. Just know there is alot more going on out there than you can see on TV, so don't rush to judgement on that CB.
