Despite coaches’ concerns, though, a collision of forces has made the age trend too fierce to counteract. The short version: In the past five years, NFL teams have committed heavily to cost-effective rookies, reserving lucrative second contracts for the game’s biggest stars. At the same time, the number of third-year juniors leaving college has swelled due in part to what Steelers general manager Kevin Colbert said is accelerated physical development and in part to a desire to get to the second, big-money contract sooner despite the low odds of most players actually cashing in. And though many of those early entry players are great talents, they face a steep learning curve when they enter the NFL. Because of strict roster limits on the number of players a team can carry and an uptick in the number of packages that rely on extra personnel, it’s now far harder to hide a less prepared draft pick on a roster?—?and that creates problems on the field. Further complicating matters, coaches and executives think rookies are less prepared than ever, but the new CBA restricts padded practices and offseason contact between players and coaches, limiting learning opportunities. Looming over all of that is teams’ reliance on the rookie salary scale, which since the 2011 CBA has guaranteed teams access to cheap players for four years and created a world in which older players have to break out in a big way to stick around after their first deal expires. And yes, that’s really the short version.