Furthermore he ran 4.45 handtimed at Miss Valley St, and even ran a 6.34 55 meter in the '87 NFL Fastest Man Contest (lost to Willie Gault 6.31). He looked fast on the field because he was indeed fast he just never ran track and didn't know how to properly run a 40, he ststed he ran his first 40 before his Senior year of college and ran 4.45
Link: https://nflfootballjournal.blogspot.com/2021/06/did-jerry-rice-run-47-forty.html?m=1