re: How is Johnny Manziel a RS freshman if he's a junior in school?

'years' of eligibility and 'academic classification' are two different animals, measured with a different stick.

Academic classification is measured in the number of credit hours you have accumalated. If you get enough credit hours accumulated by halfway through your 2nd year for example, you could be a junior academically, but still a redshirt freshman or sophomore by football (calendar years) eligibility.

Some high school graduates have already accumulated some college credit hours before they even step foot on the campus, if they took certain classes in high school.