Picking the field: A Bracketology primer

Written by Sam Werner on .

Unlike the NCAA basketball tournament, the selection process for the NCAA Division I hockey tournament is not a subjective process. There's no debating résumés or back-and-forth among the selection committee. There is a selection committee, but its job is pretty straightforward and all about placing the teams within the tournament, as opposed to picking the teams themselves. How exactly are those 16 teams selected? That's we'll look at today.

Step one: Automatic bids. This is the easy part. Each of the five conferences (Atlantic Hockey, CCHA, WCHA, Hockey East and ECAC) receives an automatic bid for its tournament champion. Prior to this year, winning the league's tournament was pretty much the only way for an Atlantic Hockey team to make the field, though Niagara looks to be in this year regardless.

Step two: At-large teams. The next part is selecting the other 11 teams using a system called the PairWise rankings. The top 11 teams in the PairWise rankings that didn't earn automatic bids will make the field. You've seen references to it in earlier posts, and here's the nitty-gritty explanation.

The committee takes every team with an RPI over .500 and compares them against one another. These teams are known as "Teams Under Comparison" (TUCs). The team that wins the most comparisons is ranked first, and so on down the line. Each comparison is made up of four parts: RPI, record against TUCs, record against common opponents and head-to-head record. Teams need 10 games against TUCs for that component to count, and all ties are broken by RPI. For the common opponents, the committee adds the sum of the teams winning percentage against all of those teams

So, let's look at an example:

Team A Team B
RPI .5504 0 .5634 1
TUCs 6-5-0 (.5455) 0 6-4-3 (.5769) 1
Common Opp. 18-7-2 (6.600) 1 17-8-3 (5.983) 0
Head to Head 1-2-0 1 2-1-0 2
Points 2 4

In that case, Team B wins the comparison and gets the PairWise point. The final score of the comparison doesn't matter, Team B still gets just one point in the PairWise rankings. Notice that, for the head-to-head comparison, each win is worth one point, making that component, theoretically, more valuable than the others. These comparisons are done between every TUC (there are usually around 30 or so), and the team that wins the most comparisons is ranked first, second-most is ranked second and so on. Theoretically, the most comparison points a team could have is one less than the number of TUCs. has a good breakdown of the current PairWise rankings, and you can also look at it in a table of comparisons won. 

In every year up until now, the 16 spots have gone to the top 15 teams in the PairWise rankings and the Atlantic Hockey champion (which was never in the top 16). That will likely change this year as AHA favorite Niagara is currently ranked ninth in the PairWise. Still, any upsets in conference tournaments by teams outside of the top 16 would eliminate at-large spots at the bottom of the standings. For example, if Mercyhurst wins the AHA Tournament instead of Niagara, and gets the league's automatic bid, a team would have to be in the PairWise top 15 to earn an automatic bid.

Step three: Seeding the field. Once the 16 teams are selected, the committee must place them in the field. The tournament is broken up into four regionals, which this year are in Manchester, N.H. (Northeast), Providence, R.I. (East), Toledo, Ohio (Midwest) and Grand Rapids, Mich. (West).

The teams are ranked 1-16 according to the PairWise rankings. Teams 1-4 get 1-seeds, 5-8 get 2-seeds, 9-12 get 3-seeds and 13-16 get 4-seeds.

The committee then goes about placing the seed lines one at a time. The only caveat is that if there is a host institution in that band, they must go to the site they are hosting (this year, for example, New Hampshire will automatically be placed in Manchester). So, the No. 1 overall seed is placed in the regional closest to it. Then the rest of the 1-seeds are slotted in the closest remaining regional. The committee does the same for the 2-seeds, 3-seeds and 4-seeds.

So, ideally, the bracket looks like this:

Region 1

No. 1 vs. No. 16
No. 8 vs. No. 9

Region 2

No. 2 vs. No. 15
No. 7 vs. No. 10

Region 3

No. 3 vs. No. 14
No. 6 vs. No. 11

Region 4

No. 4 vs. No. 13
No. 5 vs. No. 12

From there, the committee has to look at a few things. First, intra-conference matchups in the first round. Teams from the same conference cannot play in the first round, so the easiest fix is just moving teams within seed bands (i.e. swapping Nos. 13 and 15 within the 4-seed band). Next, are the 1-seeds playing any unfavorable games? The committee will move some top seeds around to avoid them having to play a true road game early. This year, for example, if New Hampshire doesn't earn a 1-seed, the committee would not send the No. 1 overall seed (likely Quinnipiac) to Manchester. Finally, are there any minor switches that could significantly lessen a team's travel needs or boost attendance. The most likely switch in that category this year is that the committee will likely try and get Western Michigan to play in Grand Rapids to help attendance at that regional.

All of these changes can be made, but the committee also would like to preserve bracket integrity (that is, having 1 vs. 16, 2 vs. 15, etc.). So it's all about hitting the right balance. I highly recommend Jayson Moy's Bracketology Blog on for all the weekly updates on what the field looks like. I also recommend College Hockey News' "You Are The Committee" tool, which lets you play around with results over the last two weeks of the season and see how they impact the PairWise rankings. See if you can get the right scenario to get Robert Morris an at-large spot in the field (hint: The Colonials should be rooting for Mercyhurst and Ohio State this weekend.)

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