Bracketology is the process of predicting the field of college basketball participants in the NCAA Basketball Tournament, named as such because it is commonly used to fill in tournament brackets for the postseason. It incorporates some method of predicting the metrics the NCAA Selection Committee will use (such as rating percentage index through the 2018 tournament, and the NCAA Evaluation Tool [NET] since 2019) in order to determine at-large (non-conference winning) teams to complete the field of 64 teams, and, to seed the field by ranking all teams from first through sixty-eighth. Bracketology also encompasses the process of predicting the winners of each of the brackets. In recent years the concept of bracketology has been applied to areas other than basketball.