Complex sentence: Greene went on to set the NCAA record for wins as a starting quarterback in a career, but over the course of those four years, Shockley did see some playing time in a modified dual-quarterback system.
Split into simpler sentences: Greene went on to set the NCAA record for wins as a starting quarterback in a career. However, over the course of those four years, Shockley did see some playing time in a modified dual-quarterback system.