From his close-in vantage point, Nelson can't take in the flow of an entire play. Instead, he will read a single player's movement, rely on his experience and then translate that movement into a mental picture of what the rest of the offense is doing. For instance, in the I formation, in which one or more backs line up directly behind the quarterback, Nelson keys mainly on the offensive guard in front of him. On plays from the I, both guards generally go directly to the point of attack. On the other hand, in split formations, in which a back lines up behind each tackle, Nelson looks at the strong side back while keeping an eye on the strong side guard. If they head in the same direction, so will the play. If they head in opposite directions, however, the play is probably a trap—with the fullback trying to lure Nelson away so the delaying ballcarrier can run through the area Nelson has vacated.
Nelson's split-second reactions are critical to the success of the Patriots' defense. Most times New England sets up its 3-4 to free the inside linebackers so they can make the tackle. The three down linemen, particularly the nose guard, sacrifice themselves in order to keep the inside linebackers from being blocked out of the play. That explains, in part, why Nelson leads the Patriots in tackles, and also why defensive linemen in the 3-4 rarely get any recognition.
The Patriots wigwag their defensive signals to Nelson from the sidelines, and Nelson relays them to the defense. If he sees the opposition in an unexpected formation, Nelson can check off and call any of the Patriots' other 12 pass coverages. "Nelson has a thorough understanding of our defensive system," says Fairbanks. "He's very aware of how teams are trying to attack us and how to adjust our defense."
Predictably, Nelson never glamorizes this responsibility. He is too bad a PR man for that. Instead, he insists on describing what a clown he made of himself when the Patriots squeaked by Buffalo 14-10 last month. In a special check-off session two days before the game, the coaches stressed that the Patriots couldn't use man-to-man coverage if the Bills lined up with a running back behind the tight end. When Buffalo came out in that formation on one play, New England was in man-to-man. Nelson, though, forgot to check off and audibilize a new defense. "It just didn't click until the snap of the ball," he says. "When I realized what they were doing, I went to zone coverage myself and tried to holler the check-off to everyone else. The result was that everyone else played a man-to-man, I played a zone, and Buffalo scored on an 11-yard pass play."
For that blunder, Fairbanks was probably tempted to give Nelson one of his dreaded Half Eyes. But how in the world can you get mad at a football player like that?