It would seem to me that the two keys to success for an NFL franchise are player acquisition and player development. That is, you have to draft well and then you have to successfully develop the players that you draft. You often hear commentators and analysts talking about franchises being good or bad at either or both of those. Of course, it's hard to separate the two. Were good NFL players destined to be good on any team, or is their development within the teams that determines their ultimate success? Obviously the answer is both, to some extent, but have their been studies that have tried to disentangle the two and compare their relative importances? Has it been done for other sports? Obviously it could be challenging to get the econometrics right, but it seems possible.