Hayes was commonly referred to as "the Judge" and also as "Lester the Molester" because of his Bump and run coverage. A big Star Wars fan, during pregame interviews for Super Bowl XVIII he declared himself the "only true Jedi" in the NFL. He was also known for using Stickum before it was banned in 1981 in a rule bearing his name. He had a distinct stance, as exemplified on his photo on the Raiders' home page, crouching very low when facing the opposing wide receiver.
He was known as one of the greatest shutdown cornerbacks in NFL history. His best performance was probably in Super Bowl XVIII. He had only one tackle, but that was because he so effectively covered Charlie Brown and Art Monk that Joe Theismann hardly threw to the left side of the field.
Hayes was a lifelong stutterer until well into his professional career. He tended to stay quiet, rather than draw attention to his condition. For this reason, he was often looked upon as not very smart, but after successful treatment, people "couldn't shut him up," according to former Raiders coach John Madden, and it was revealed that Hayes was an articulate, intelligent man.