Premise: Ron Waller (born February 14, 1933) was a National Football League running back for the Los Angeles Rams from 1955 through 1958 and for the American Football League's Los Angeles Chargers in 1960. He was the head coach of the NFL's San Diego Chargers for the final six games of the 1973 season, and held the same position with the Philadelphia Bell of the World Football League in 1974.
Hypothesis: Ron Waller was around in the Pro series for at least six years.