Arpad Elo

Arpad Emmerich Elo (born Élő Árpád Imre; August 25, 1903 – November 5, 1992) was the creator of the Elo rating system for two-player games such as chess. Born in Egyházaskesző, Kingdom of Hungary, he moved to the United States with his parents in 1913.
Elo was a professor of physics at Marquette University in Milwaukee and a chess master. By the 1930s he was the strongest chess player in Milwaukee, then one of the nation's leading chess cities. He won the Wisconsin State Championship eight times.
Elo died in Brookfield, Wisconsin.
The Elo rating system.
Elo is best known for his system of rating chess players. The original chess rating system was developed in 1950 by Kenneth Harkness, the Business Manager of the United States Chess Federation. By 1960, using the data developed through the Harkness Rating System, Elo developed his own formula which had a sound statistical basis and constituted an improvement on the Harkness System. The new rating system was approved and passed at a meeting of the United States Chess Federation in St. Louis in 1960.
In 1970, FIDE, the World Chess Federation, agreed to adopt the Elo Rating System. From then on until the mid-1980s, Elo himself made the rating calculations. At the time, the computational task was relatively easy because fewer than 2000 players were rated by FIDE.
FIDE reassigned the task of managing and computing the ratings to others, excluding Elo. FIDE also added new "Qualification for Rating" rules to its handbook awarding arbitrary ratings (typically in the 2200 range, which is the low end for a chess master) for players who scored at least 50 percent in the games played at selected events, such as named Chess Olympiads. Elo and others objected to these new rules as arbitrary and politically driven.