Sports rating system

A sports rating system is a system that analyzes the results of sports competitions to provide ratings for each team or player. Common systems include polls of expert voters, crowdsourcing non-expert voters, betting markets, and computer systems. Ratings, or power ratings, are numerical representations of competitive strength, often directly comparable so that the game outcome between any two teams can be predicted. Rankings, or power rankings, can be directly provided (e.g., by asking people to rank teams), or can be derived by sorting each team's ratings and assigning an ordinal rank to each team, so that the highest rated team earns the #1 rank. Rating systems provide an alternative to traditional sports standings which are based on win–loss–tie ratios.

College football players in the United States

In the United States, the biggest use of sports ratings systems is to rate NCAA college football teams in Division I FBS, choosing teams to play in the College Football Playoff. Sports ratings systems are also used to help determine the field for the NCAA men's and women's basketball tournaments, men's professional golf tournaments, professional tennis tournaments, and NASCAR. They are often mentioned in discussions about the teams that could or should receive invitations to participate in certain contests, despite not earning the most direct entrance path (such as a league championship).[1]

Computer rating systems can tend toward objectivity, without specific player, team, regional, or style bias. Ken Massey writes that an advantage of computer rating systems is that they can "objectively track all" 351 college basketball teams, while human polls "have limited value".[2] Computer ratings are verifiable and repeatable, and are comprehensive, requiring assessment of all selected criteria. By comparison, rating systems relying on human polls include inherent human subjectivity; this may or may not be an attractive property depending on system needs.

  1. ^ Fagan, Ryan (2011-03-09). "Sorting through teams on one big bubble". Sporting News. Retrieved 2011-03-24. This is a look at 20 of the teams (in alphabetical order) residing on this year's big ol' bubble. We've included three statistical rankings. The RPI (ratings percentage index, taken from collegeRPI.com) is considered the standard and is provided to committee members during the selection process. The two other ranking indexes include margin of victory in their formulas—the Pomeroy ratings (at kenpom.com) and Sagarin ratings (via USA Today)—aren't new but have played an increased role in discussions about potential seeds during this college basketball season.
  2. ^ Ken Massey [@masseyratings] (3 Nov 2014). "@kenpomeroy human polls have limited value. Computer systems can objectively track all the teams. http://www.masseyratings.com/cb/compare.htm #all351" (Tweet). Retrieved 9 Nov 2014 – via Twitter.