Quite simply, the Eagles' offense is built to spread out defenses and give ball carriers space to run. And no one in the NFL capitalized on those opportunities more than Sproles during his three-year run with the New Orleans Saints.
Take a look at the chart, which shows that Sproles has led the NFL since 2011 with 1,888 yards after the catch, according to ESPN Stats & Information. That figure represents 95 percent of his total receiving yards over that period, and it is the precise skill that Eagles coach Chip Kelly attempts to maximize.
Last season, Eagles running back LeSean McCoy accumulated 603 YAC. His average of 11.6 YAC per catch led the NFL.
(Statistical quirk: McCoy had more YAC than net receiving yards because of the frequency of receptions behind the line of scrimmage. The same goes for the Saints' Pierre Thomas. McCoy and Sproles, in fact, have the NFL's most catches behind the line -- 105 and 95, respectively -- over the past three years.)
Why do the Eagles need two players who do the same thing? I don't think it's quite that simple. Sproles and McCoy are both excellent runners in the open field, but in different ways and from different places.
At the top, it's worth pointing out that McCoy led NFL running backs with 366 touches last season and ranks No. 1 in offensive snaps per game (54) by running backs over the past four seasons. Sproles, on the other hand, has only 815 offensive touches in his nine-year career. Perhaps Sproles' presence can get McCoy a bit more rest without sacrificing a key threat in their offense.
Second, Sproles proved especially productive in New Orleans when lined up somewhere other than the backfield. His 89 receptions in those situations since 2011 is twice that of the next-closest running back, Marcel Reece (44). Such familiarity with the slot and outside receiving positions give the Eagles a scary potential to use Sproles and McCoy on the field at the same time.
All of this is to say what has seemed obvious from the start: The Eagles and Sproles are an ideal match. It makes perfect sense.