Greyshirts was created in 1933.

A player that greyshirts starts his 5 year athletic eligibility the 2nd semester of his first year. He can then redshirt the following year and have 3.5 years of eligibility remaining. Since football is a first semester sport, he can then play 4 full seasons of football, having practiced with the team an additional 2 years, one as a grey shirt (practicing in the fall but not becoming a student until the spring) and one as a red shirt (enrolled and practicing, but not appearing in a game).

Someone taking the greyshirt route does not enroll in college until the spring semester. Therefore, in recruiting, he/she wouldn't be considered a true recruit for that year and sign a LOI until the next years signing day. EX: Running back that needs maybe more than one year to physically develop graduates H.S. in May 2008. Greyshirts, so he doesn't attend college till spring 2009. He doesn't sign a LOI until Feb. 2009 and may or may not redshirt in 2009-2010 season. He is then considered a freshman, but still has 5 years of eligibility left (4 that he can play). So his eligibility to play D1 ball doesn't run out until 2013-2014 season rather than 2012-2013.