Each year, the cycle of conversation about pro days seems to be the same. First, everyone thumps the table about how pro days don't matter, then we all follow pro day results as if Simon Cowell were judging each and every prospect.
But why pro days?
Pro days are most useful to small-school prospects who weren't invited to the combine. This hearkens back to a day when there wasn't as much of a cottage industry and national coverage around the combine and college all-star games.
Pro days—especially at larger schools that would invite local small-school prospects—were the only real avenue for some athletes to get to the next level.
More importantly for NFL teams, pro days are like the teacher who tells students that a test will be open book. There is literally no reason for any of the students to fail, but some still do.
In the same way, pro days are designed to showcase an athlete's skills. Many parts of it are stringently scripted so that there can be no mistakes. Those who "fail" are likely failures for a pretty big reason—whether it's laziness, apathy or something worse.
So, which pro days left us with more knowledge about the participants?