At Washington State, Chaplin was named Pac-10 Coach of the Year four times, District Coach of the Year seven times, and International Coach of the Year in 1978. He coached a number of outstanding individual athletes, including former world record holder Henry Rono.

Chaplin continues to serve the sport beyond his retirement from Washington State. He was the 2000 men’s Olympic Track & Field Head Coach, and he continues to serve as chair of the USATF men’s track & field committee. Chaplin served as a USATF referee from 2001-04, as a five-time Texas Relays referee, as a National High School Outdoor Track & Field Meet referee since 1999, and as Penn Relays referee since 1991. He has also served as a consultant to the Nike Corporation, as well as to the Olympic Trials at Sacramento.