Does that mean Kelly places size above all else when evaluating a player? Certainly not. If a player is a stud on the field but has measurements that aren't average or better for his position, the coach and his staff always will go with the film.
Eagles general manager Howie Roseman and his scouting staff, though, tweaked their evaluations this offseason to reflect Kelly's preferences, some having to do with the transition the defense would undergo moving from a 4-3 to a 3-4.
The assignment was as simple as Kelly's adage: Find talented players who are big so they can beat up equally talented players who are smaller. But with advanced scouting, breaking down a player can be a complex practice in which precise measurements can provide a red flag.
"There's certain things in every staff, in every different scheme you're dealing with, that change," Eagles player-personnel executive Rick Mueller said. "So there were a lot of things that changed. Arm length, I think, was an emphasis. But it was an emphasis for the last staff, too."
Abnormally long arms
Andy Reid drafted his share of large rookies, but never did he select so many tall players as Kelly did in his first draft. Four rookies were taller than 6-foot-4. Three had abnormally long arms, greater than 34 inches.
Every time Kelly spoke with reporters after a long player was drafted, he mentioned the player's arm length. For instance, he had this to say of top draft pick Lane Johnson: "What really was a factor is I think you see a guy that is 6-6, he's 300 pounds, and has 35-inch arms."
The Eagles aren't the only team that may focus more intently on arm length. Tom Gamble, Eagles vice president of player personnel, has scouted for the 49ers, Colts, Ravens, Panthers, and originally for the Eagles when his father, Harry, was general manager.
"I've used it everywhere I've been," Gamble said. "I think it's huge. I really do."
Arm length is most important in the trenches, where linemen engage in close combat. Having a long wingspan obviously also helps receivers and defensive backs reach for passes, but it comes in handy in man-to-man defense.
"If you're bigger than everybody else and your arms are longer than everybody else's, it's a little easier to keep people off you," Mueller said.
Though the Eagles need most of their rookies to play right away, there is still some projection involved. Johnson will peak at such-and-such time and he should do so as he maxes out his "growth potential."
When Johnson visited the Eagles before the draft, it was nearly two months after the NFL combine, where he had all his measurements done. But Kelly's sports-science staff had Johnson remeasured a few weeks before the draft, and based on the size of various parts of his body, including his arms, projected his ideal weight and body-mass index.
"That's why they're constantly remeasuring over the course of the spring, or the combine measurement was off and let's measure the arm when he's in," Gamble said. "Over time, there are some guys that aren't great athletes that have great wingspans, that have great range, that aren't going to look the prettiest but because of the wingspan are going to be able to function as a tackle, on the edge."
Gamble wasn't referring to Johnson, who has incredible athleticism for a tackle. But he could have been talking about defensive end Clifton Geathers, acquired in a trade this offseason. The 6-8 lineman has unusually long arms - 373/4 inches. But in his first two seasons, Geathers' length has not translated on the field.
Eagles scouts write up players - both college and pro - based on the evaluation of their film. They include body measurements and speed-and-agility numbers in reference to parameters for each position computed by Alec Halaby, the Eagles' analytics ace.
If the player falls above or below the averages at each position, the scout adds a tag or alert to the evaluation.
"We take our direction from the coaching staff, and obviously that comes down through Howie," said Ed Marynowitz, assistant director of player personnel. "So if there's something like arm length that we're going to emphasize at certain positions, those [long-armed] guys, we're going to make sure that we're talking about them in a different light."
The same applies to prospects who fall below the averages. Gamble gave an example of the type of scouting report he may pass along to Roseman for a college tackle who has short arms.
"You're always, 'Jeez, you got a guy at tackle. You kind of like his feet. You kind of like the way he moves, but he's got 311/2 arms,' " Gamble said. "Well, now, 'We may have to move him inside. He doesn't play with power. He's more of an outside guy with good feet. Now what are we going to do?'
"Those are the dilemmas you have."
Contact Jeff McLane at firstname.lastname@example.org. Follow on Twitter @Jeff_McLane.