The 20 titles put him in a 14th-place tie with Wayne Webb, Amleto Monacelli and Tommy Jones on the all-time list.
Ritger also won two titles in the Classic Division at the National USBC Championships, in Team (1967) and All-Events (1977).
A gentleman on the lanes and off, Ritger won the PBA's Steve Nagy Sportsmanship award on two occasions.
He became recognized as one of the most effective bowling instructors in the world, running over 500 clinics in 24 countries covering five continents.
He graduated from the University of Wisconsin - La Crosse with a double major in Physical Education and Recreation.