USCF first instituted a rating system for over-the-board play in 1950, using a calculation formula devised by Kenneth Harkness. In 1960, the USCF adopted a more reliable rating system invented by Arpad Elo, a college professor of physics who was a chess master. Elo worked with USCF for many years. The system he invented, or a variant of it, was later adopted by FIDE, and is utilized in other games and sports, including USA Today's college football and basketball rankings. USCF has made further adjustments to the rating calculation over the years; the present calculation was influenced by the "Glicko rating system" developed by Prof. Mark Glickman, a significant refinement of Elo's system.