 Hayes' speed forced other teams to go to a zone since no single player could keep up with him.Spreading the defense out in hopes of containing Hayes allowed the Cowboys' talented running game to flourish, rushers Don Perkins, Calvin Hill, Walt Garrison and Duane Thomas taking advantage of the diminished coverage at the line of scrimmage.In the 1967 season, Hayes led the NFL in punt return yards, and went on to set an NFL playoff record with 141 punt return yards in Dallas' 52-14 win over the Cleveland Browns.