The NCAA Selection Procedure for 1997-1998

© 1998, Joe Schlobotnik (archives)

URL for this frameset: http://www.slack.net/~whelan/tbrw/tbrw.cgi?1998/pairwise.shtml

See also

• You Are The Committee, an interactive run through the selection process
• The "What If" interface to examine the selection criteria based on hypothetical outcomes of the conference tournaments, available in bracket or text forms
• The Season Ended Today, 1998 March 22
• How the 1998 seeding was determined
• NCAA seeds 1996-1998

In this enlightened age, the NCAA Division I hockey tournament is seeded largely by statistical analysis. So in principle college hockey fans should be able to predict on their own how the tournament will be seeded in advance. Problem is, the selection process has been changing slightly every year, and in the past it's been difficult to find out the current rules in advance. After the tournament pairings were announced last March, Selection Committee chair Joe Marsh provided a detailed explanation of how it was done to Adam Wodon of US College Hockey Online, a web site devoted to college hockey. And the NCAA Division I Men's Ice Hockey Committee decided in July to retain the selection criteria from last year. Thus, with the occasional inquiry to the NCAA for fine-tuning, we are able to say with some confidence how things will be done this year.

The Basics

First of all, from the NCAA's point of view, only official games played between established programs with 20 games against Division I teams on their schedule count towards the selection process. This season those teams are all the members of the WCHA, CCHA, ECAC and Hockey East, plus Independents Army in the East and Air Force and Mankato State in the West. Exhibition games, and games against Canadian or Division II or III teams are irrelevant. Games against Division I teams not playing a full Division I schedule, such as Niagara and Holy Cross, or the "developing program" Nebraska-Omaha, in its first year of NCAA operation, do not contribute to any of the selection criteria, although they can count towards the 20 games to qualify a team for the tournament. (the fine print)

The underlying principle behind the current selection process is the pairwise comparison. One team is compared to another team based on five criteria:

Ratings Percentage Index

Also known as RPI, not to be confused with Rensselaer Polytechnic Institute. This is a weighted average measuring a team's record and strength of schedule and consisting of 0.35 times the team's winning percentage, plus 0.50 times their opponents' average winning percentage, plus 0.15 times their opponents' opponents' winning percentage. USCHO maintains a listing of the current RPI, updated automatically. (the fine print)

Record in last 20 games

(the fine print)

Record vs. Teams Under Consideration

A Team Under Consideration, or TUC, is a team with a record of .500 or above in games that count towards the selection process, as defined above. (the fine print)

Record vs. Common Opponents

(the fine print)

Head-to-head record

A team wins one point towards the comparison for each of the first four criteria, and one point for each head-to-head game in which they defeated the other team in the comparison. Whichever team gets more points wins the comparison, and if it's a tie, the team with the higher RPI wins.

Every Team Under Consideration is compared to every other TUC in this way. The total number of such comparisons won is called the Pairwise Rating (PWR). (The current PWR is also available on USCHO.) This number can be used to rank the TUC, and in the past it was believed that the teams were seeded in the order of these Pairwise Rankings, but that is not precisely how it's done. The PWR is used to get a rough sense of which teams are in contention for which spots, but then those teams are placed according to the pairwise comparisons among or between them. For example, if you're battling it out for the twelfth and final spot in the postseason, it doesn't matter how you compare with the fifth-rated team. Thus a two-way tie is impossible, since one team will always win the pairwise comparison. If three teams end up in an unresolvable tie (rock-scissors-paper), we go to the RPI to resolve the deadlock.

What Do We Do With the Numbers?

The NCAA tournament consists of twelve teams, divided for the first round and a half into two regionals, East and West. In each regional, two teams receive first-round byes while the other four play on the first night. On the second night of the regional, the two bye teams play the two first-round winners, with the two survivors from each regional then advancing to the national semifinals the following weekend. The selection and seeding process can be divided into the following steps:

Qualification

The regular season (the fine print) and tournament champions in each of the four conferences receive automatic berths, which accounts for between four and eight of the twelve teams. The remaining four to eight at-large teams are selected according to the pairwise method. There is the one stipulation that each conference must have at least two representatives in the tourney.

Byes

Any team which wins both the regular season title in its league and its conference tournament receives an automatic first-round bye; since there are two conferences in each region and two byes in each regional, this will fill between zero and two of those slots in a given region. The other bye(s), if any, are given to the best team(s) in the appropriate region(s) according to a pairwise analysis.

Regions

There are now four remaining spots in each regional to fill with the other eight teams. If those eight teams are evenly divided, four from each region, the two better teams in each region play in their respective regionals, while the two lower teams are "shipped out" to play in the opposite region. If there is an imbalance, the bottom team(s) from the over-represented region are placed into the other region before the swap. (snotty aside) However, the host schools (Michigan in the West and RPI in the East this year) must be kept in their own regions. (the fine print) Also, see "Fine Tuning".

Seedings and Pairings

Once the four non-bye teams in each regional are determined, they are placed in the three to six positions according to their pairwise comparisons. The four and five seeds will play in the first round, with the winner to face the one seed, while the three and six seeds will meet for the right to play the two seed.

Fine Tuning

At this point, we have a setup for the tournament according to the numbers, but there could be other problems with it. For instance, all four first-round contests could be rematches of the conference title games, or the teams with the biggest fan bases could be playing outside of their regions. These are both considered undesirable by the NCAA, so the committee can shuffle things a bit, either by altering the seedings within a region, or choosing to send different teams to the opposite regionals. First-round intra-conference matchups are positively verboten, and potential second-round games between teams in the same conference should be avoided, especially if the teams met in their conference playoffs. If two teams are swapped within a region to eliminate a second-round matchup, the other two teams will be swapped as well to retain the first-round pairings, if that doesn't cause more problems. Also, teams can be shifted to different regions to increase attendance.

Putting It In Practice

Here's how the procedure was actually applied to seed the 1998 tournament, and here's a summary of how it's gone for the last three years. To follow through the procedure yourself, try this script.