C.H. Underwood played six-man football at O’Brien and then returned to coach at O’Brien, where his team won the 1972 state championship, the first year that the UIL crowned a state champion in six-man football. He is the author of the book “Six-Man Football” which is considered the bible for six-man football coaches. Underwood was also the line coach for Knox City-O’Brien Class A 11-man state championship team in 1983. He coached basketball, too, receiving a milestone award from the Texas Association of Basketball Coaches for reaching 300 wins as a varsity basketball coach. He compiled a 356-157 record and never had a losing season in 21 years as a basketball coach.