NFL Combine:what does it Prove?

Vince Young who Dominated USC in the Rose Bowl&Helped lead the way for His Texas Longhorns for the National Title,over the weekend had to participate in a NFl Mental test of some sorts.common sense what he accomplished on the field should speak for itself. alot of QB"s have mental skills but end up holding a clip boards upon playing in the NFL. I wondr why this is a story at all? guys can score high scores in various routnes&things,but unless you are on the field&doing something nobody is gonna truly know what anyone has as far as playing at the Highest level Possible.i think the NFL while the best sport going,doesn't always mean you have to Prove anything in a combine.I mean there have been players over the years who came in off the street&Proved they Belong.i've never felt that skills tests in any Profession or job proved anything.