Pro days matter. Just not very much, and especially not to quarterbacks. However, many prospects not invited to the combine get their chance to showcase their timed and measured athleticism. And while it's good practice to add a tenth of a second onto pro day 40 times, the rest of the workout figures are usually pretty accurate. Also, after the combine is time to watch film of deep sleepers and look into extra film of some of the top prospects (previous seasons). Even re-watching some games can't hurt. You'll notice a few prospects at the same position listed back to back. That means they simply finished with the exact same grade in my system. Speaking of system, that's what it comes down to with those players. Different specialties for different systems.