J. Isaac Miller codevelops new chess rating system for games played at various time controls

J. Isaac Miller

Associate professor J. Isaac Miller, along with other researchers, developed a new rating system, the Universal Rating System (URS), for chess games. The development of the new rating system was supported by the Grand Chess Tour, the Chess Club and Scholastic Center of Saint Louis, and the Kasparov Chess Foundation. The URS will be used to publish monthly ratings that will be used for invitations to GCT events in 2017. They are scheduled in Paris; Leuven, Belgium; St. Louis, Missouri; and London.

The URS differs from previous rating systems used for chess tournaments in several ways. The universal rating is the system's best assessment of a player's strength at games played for which each player has at least two hours for their first 60 moves, but using information about game results played at faster time controls. In contrast, extant rating systems are published for games played at different time controls.

In comparing game results at different time controls, the URS assigns less weight to games played at faster time controls, recognizing that faster games result in more blunders. These weights are estimated to be different for each player, so that some players’ propensities to blunder increase faster than those of other players. In addition to a rating for play at the slowest time control, the URS publishes a so-called rapid gap and blitz gap, which are described as follows:

  • Rapid Gap: the Universal Rating advantage the player would need for a 50 percent expected score in rapid (game in 30 minutes each) against an opponent whose quality and consistency of play do not worsen at quicker time controls.
  • Blitz Gap: the Universal Rating advantage the player would need for a 50 percent expected score in blitz (game in 5 minutes each) against an opponent whose quality and consistency of play do not worsen at quicker time controls.

A second major difference from existing rating systems is that the URS reassesses the ratings of all players in the system at regular intervals, down-weighting older games to choose ratings that best explain recent observed game outcomes.

The GCT is an international circuit of high-profile chess tournaments. Major tournaments that have been featured include Norway Chess, the Sinquefield Cup, and the London Chess Classic. The CCSCSL has hosted U.S. Chess Championships and U.S. Women’s Chess Championships since 2009. It was named the 2010 Chess Club of the Year by the U.S. Chess Federation, and the U.S. Senate designated St. Louis the National Chess Capital in 2014. The Kasparov Chess Foundation was founded by former world chess champion Garry Kasparov to promote the educational benefits of chess.

Miller, whose research focuses on statistical time series, was joined on the team by Mark Glickman, senior lecturer in the Department of Statistics at Harvard University and developer of the Glicko rating system; Jeff Sonas, founder of California-based Sonas Consulting and developer of the Chessmetrics rating system; and Maxime Rischard, a doctoral student in the Department of Statistics at Harvard University.