The Elo-Rating-System
The Elo rating system is a mathematical framework used for calculating the relative skill levels of players in Zero-Sum-Games. It is named after Arpad-Elo, a Hungarian-American physics professor and Chess master who developed the system to improve upon the previous Harkness-System. While it was originally designed for Chess, it has become the gold standard for ranking competitors in various fields.
How the System Works
The core of the Elo system lies in Probability-Theory. A player's rating represents their expected performance; when two players compete, the difference in their ratings predicts the outcome of the match. If a high-rated player wins against a low-rated player, few points are exchanged. However, if an underdog achieves an upset victory, a significant number of points are transferred, reflecting a change in the estimated skill levels. This adjustment process often utilizes a Logistic-Distribution to model the probability of victory.
Global Implementation
Today, the Elo-Rating-System is used by the FIDE to rank international Chess players. In the realm of Digital-Media, Video-Games such as League-of-Legends and Counter-Strike utilize modified versions of the algorithm for Matchmaking. Furthermore, Association-Football and American-Football analysts use Elo variants to provide power rankings for professional teams.
Technical details and historical data can be found through the Wikipedia entry on Elo or the official FIDE website.