A lot (not all) of first round picks are drafted based on potential and how they project as a prospect. Marlon has above average size and athleticism in regards to being a NFL corner. That alone will probably get him drafted a little higher than if he were 5"10. Also, good cornerbacks are at a premium in the NFL because of how pass heavy the modern game has become..I just don't see Marlon Humphrey as NFL ready yet!