22nd NFL season
He straddles the line of scrimmage on the side of the field opposite the head linesman, looking for illegal movement along the defensive line and false starts. As the backup clock operator, the line judge must keep the time on the field in case the stadium clock malfunctions—and he has the power to adjust the time. He is responsible for deciding whether the quarterback crossed the scrimmage line before throwing a pass and, on punts, whether a player is illegally downfield before the ball is kicked.
13th NFL season
V.P., Government relations
He stands about 25 yards downfield, usually on the same side of the field as the tight end, then watches for infractions by or against the tight end. He must be able to move quickly from side to side. "He's what we call the windshield wiper because he has to run from one side of the field to the other so often," says Pereira. He's a key arbiter on pass interference calls, monitors the 25-and 40-second play clocks for delay of game and, along with the field judge, rules on field goal and extra-point attempts from under the goalpost.
9th NFL season
The equivalent of a referee in boxing, he is instrumental in keeping the players' emotions under control. Positioned five yards off the line of scrimmage, he watches for false starts, holding by interior linemen and interference on short passes, while constantly getting bumped or slammed into. Because of that contact some umpires wear a flak jacket. "They're probably 10 times more likely than anyone else to get an injury," says Pereira. "They're the toughest officials we have."
7th NFL season
He straddles the line of scrimmage before the snap, watching for encroachment, offside and false starts on his side of the field. He also marks the spot of a ballcarrier's forward progress and oversees the chain crew. All officials are expected to know what down it is, but the head linesman has the last word. On pass plays he drifts downfield to help on situations involving interference and illegal contact. He also assists the referee on intentional-grounding penalties.
9th NFL season
P.E. and athletics professor
He lines up 20 yards downfield from the head linesman. Like the field judge, he has to sprint downfield to beat the ballcarrier to the goal line on a touchdown. He watches for pass interference, keying on the receiver split widest on his side of the field. At halftime he and the head linesman switch sides of the field. "That's to prevent one coach from thinking the other coach is working the official on his side so hard that he'll start getting the calls in the second half," Pereira says.