||This article may contain original research. (March 2008)|
Bracketology is the process of predicting the field of 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 what the NCAA Selection Committee will use as its Ratings Percentage Index in order to determine at-large (non-conference winning) teams to complete the field of 68 teams, and, to seed the field by ranking all teams from first through sixty-eighth. ESPN's Joe Lunardi is the inventor of the term "bracketology", starting first as the owner and editor of the Blue Ribbon College Basketball Yearbook and ending up as the resident bracketologist on ESPN. He also teaches an online course at Saint Joseph's University titled "Fundamentals of Bracketology". Although Lunardi invented the term, he is ranked only 23rd in the past four years' results of the tournament. In recent years the concept of bracketology has been applied to areas outside of basketball.
Using the NCAA basketball tournament selection process, the RPI, and the seeding and balancing process, a "bracketologist" places teams in the tournament in the various regions (most commonly East, West, Midwest, and South however sometimes the region names are changed to reflect the host cities). Some bracketologists go as far as placing teams in which "pods" they will play in the first and second rounds. Generally, the lists also show the last four teams in and the first four teams out. However, these brackets change daily as conference tournaments continue and teams automatically qualify for the tournament.
A bracketologist's credibility is judged on how many teams he predicts correctly being in the tournament and the average difference between the bracketologist's projected seed and the actual seed assigned by the NCAA Selection Committee. The difference between projected matchups and the differences between the "pods" selected in the first and second rounds are less important.
Non-basketball applications 
Bracketology as a discipline has spread beyond a focus on basketball, into other sports, as well as pop culture, history, nature, and other topics where a loose application of binary opposition may be profitable for study or enjoyment.
This spread has been helped along by literary agent and writer Mark Reiter and sports journalist Richard Sandomir, who have edited two books on bracketology as applied to the world around them, most recently The Final Four of Everything, which was published by Simon & Schuster in May 2009.
See also 
- , additional text.
- The Tournament of Books at The Morning News
- Bracketology article in New York Times
- Publisher website for The Final Four of Everything by Mark Reiter and Richard Sandomir
- ESPN: Joe Lunardi's Men's Bracketology
- ESPN: Charlie Creme's Women's Bracketology