Ratings Overview

The MyPoolStats rating system calculates Wisconsin-area pool player ratings directly from competitive performance.  Match results are collected from participating events like tournaments and leagues throughout the year and from across the state and beyond.  Ratings are provided for all to use.  Other features include individual player rating history, a system-wide player ranking, a calculator for determine match odds between players, and how the system can be leveraged for handicapping events.

Advantages of the System

  • Ratings are mathematically measured from players' game win/loss record against others.  Every game counts.
  • Automatically accounts for differences in player skill and number of games played.
  • The same rating scale is used for everyone.
  • Open and transparent system - all the information behind the ratings is available.
  • Color coded ratings to show reliable established ratings versus more preliminary ratings.
  • Ratings are updated year-round from participating events across the state and beyond. 
  • Compatible with tournament, league, and match play.
  • Resistant to sandbagging.
  • Provides matchup odds between players.
  • Can be used for partial or fully handicapped tournament or match play.

Basic Process

A player is given an initial rating when their first match is entered in to the system.  The rating system comparison chart below is used to estimate a rating based on an established ratings from another system or known ability.

rtg comp chart

 The rating adjustment formula takes over from there.  Ratings are updated for both players after each match.  The formula has two parts:

  1. How the players actually performed versus how they were expected to perform.
  2. The “fit” on the player's ratings.

The difference between the player's ratings is used to determine the expected match outcome.  If the match score matches the expected result, then the players performed as expected and the rating change for both players is zero.  Rating changes occur when the final match score differs from the expected result.  The rating for the player that over-performed goes up, and the rating for the player that under-performed goes down.  The amount of change depends on how different the final match score is from the expected result.

The "fit" on a rating describes its reliability. The system adjusts new players quickly at first and then taper off as the player becomes more established.

The next section contains more details about how and why it works.