There are all types of wide receivers.
Tall ones. Short ones. Fast ones. Not as fast ones. Strong ones. Not as strong ones. Receivers with great hands. Who run great routes. Who have great body control.
Most are some combination of the above.
Asked to name what kind of receiver would benefit most from the NFL-mandated emphasis on illegal contact downfield, the Eagles varied in their answers. Some said the restrictions on pass defenders would equally aid all receivers.
But if a specific sort was cited, aside from the ideal and rare of "big and fast, it was quicker receivers who aren't as physical.
"Big, fast guys benefit from everything, I think," offensive coordinator Pat Shurmur said this week. "But anytime you can't grab a guy, I think maybe guys that are less physical don't have to worry about playing with somebody hanging all over them down the field."
While the league has said that limiting contact downfield affects both offense and defense, the large majority of penalties called this preseason have been on defenders who have made contact with receivers beyond five yards.
Officials have called nearly everything - a grab, a pull, and even a pinch of the jersey. When they have whistled the offense, though, it has generally been against receivers who use their hands to separate at the top of their routes.
Since Chip Kelly became coach, the Eagles have stressed the importance of finding bigger receivers to counter the rowing number of rangy outside cornerbacks. The Eagles themselves signed two larger corners last year in Cary Williams and Bradley Fletcher.
The stricter enforcement would seem to limit the effectiveness of size in the passing game - on both sides - and the Eagles' emphasis on getting bigger and more physical on the outside.
Kelly, however, disagrees, particularly in the assessment that less physical receivers (read: DeSean Jackson) will benefit most.
"The only thing I think with the rule that's different is you can't [make contact] after five yards," Kelly said Tuesday. "But for five yards you can [make contact]. So that hasn't changed. . . . They're going to get in your face and cover you for five yards the way they've always covered you for five yards."
The Eagles consistently saw man-to-man, press coverage defense last season, perhaps more than any other team. Kelly said during the offseason that the No. 1 attribute he was looking for in a receiver was his ability to get separation against man defense.
Jackson wasn't at his best against cornerbacks who specialized in man-press defense. He sometimes had trouble getting off the line. But to suggest it was a major problem would be to overlook his 82 catches for 1,306 yards and nine touchdowns.
Kelly made the decision to part with Jackson in January. Assuming football was the only reason, as the Eagles coach has said, the timing of Jackson's ultimate release was curious.
Kelly said he found out at the owners' meeting in March about the league's intention to enforce the illegal-contact rule to the letter. Two days after the Eagles returned from Orlando, Jackson was cut.
"It's really not a rule change. It's just an emphasis," Kelly said, because defenders were making contact past the five-yard limit. "They're just cleaning that part of it up."
Eagles wide receivers coach Bob Bicknell said that he expects every type of receiver to take advantage of the new "emphasis." But he has noticed some cornerbacks haven't been as physical playing man-press this preseason.
"They're more of a mirrored press," he said. "They're giving you some space. They're not jamming as much."
Bill Davis, who admitted Tuesday that he was surprised by how closely officials have called illegal contact, said that he was worried about all types of receivers. But the Eagles defensive coordinator did concede that less physical and quicker receivers could be more difficult to stop.
Defensive backs coach John Lovett agreed: "Those guys can now get in and out [of routes] more easily. On both sides, getting in and out of cuts is going to be a premium because you can't use anything to separate. You can't use your hands."
The Eagles' top three receivers are versatile and can't be easily labeled. But Kelly has pointed out the advantage of their size and physicality, particularly the 6-foot-4, 230-pound Riley Cooper and the 6-3, 212-pound Jordan Matthews.
"So, maybe I'm screwed?" Cooper said.
Not necessarily. Cooper, Matthews, and Jeremy Maclin have other skills. But Jackson's greatest trait - his speed - would seem to give larger cornerbacks without the use of their hands beyond five yards more trouble.
"It will benefit him more obviously because they can't get their hands on him," Cooper said. He added: "But it's extremely beneficial for all receivers."