2012: A Bracketing Adventure (Episode I)
Despite the NCAA's recent attempts at transparency (which I applaud), many in the public still don't understand exactly how the selection committee builds the bracket. You can become an expert by reading the full details here, but it boils down to three steps: selection, seeding, and bracketing.
Crashing the Dance attempts to predict the selection and seeding based on the committee's past behavior, but not the placing of teams into the bracket. Once the 1-68 seed list (also known as the S-Curve) is set, bracketing is essentially a straighforward algorithm.
I decided to try my hand at following the committee's published bracketing procedure using the latest (through Wednesday's games) Crashing the Dance 1-68 seed list. Keep in mind this is in no way meant to predict how Sunday's bracket will turn out. This is merely an exercise to demonstrate how the committee could bracket a theoretical S-Curve using the actual sites and bracketing principles. That said, we may gain some insight into decisions the committee will have to make Sunday and how some scenarios could play out.
Before we start assigning region and pod sites, let's identify which teams are prohibited from certain sites based on the committee's criteria:
A team will not be permitted to play in any facility in which it has played more than three games during its season, not including conference post-season tournaments.
A host institution’s team shall not be permitted to play at the site where the institution is hosting. However, the team may play on the same days when the institution is hosting.
In addition to those criteria, BYU does not play on Sunday for religious reasons, so they cannot be assigned to a pod or region with Sunday games scheduled.
Pod site prohibitions (not comprehensive)
Albuquerque - New Mexico
Louisville - Louisville
Pittsburgh - Duquesne
Portland - Oregon
Columbus - Ohio State, BYU
Omaha - Creighton, BYU
Greensboro - BYU
Nashville - BYU
Region site prohibitions (not comprehensive)
Boston - Boston College
Phoenix - Arizona State
Atlanta - Georgia Tech, BYU
St. Louis - Saint Louis, BYU
The committee will then place the four “number 1 seed†teams seeded 1 through 4 in each of the four regions, then determine the Final Four semifinals pairings, making best effort to pair the top No. 1 seed’s region against the fourth No. 1 seed’s region and the second No. 1 seed’s region against the third No. 1 seed’s region.
The main principle to follow on the first line is teams will remain in or as close to their areas of natural interest as possible.
1. Kentucky - South (Atlanta)
Atlanta and St. Louis are roughly the same distance from Lexington, depending on exactly how you measure, and St. Louis could actually be much closer for travelers from the western part of the bluegrass state. With Missouri moving to the SEC, you could argue that St. Louis is also a "natural" region forKentucky. However, Atlanta seems the more natural region for Kentucky, especially given the recent frequency of the Georgia Dome as host of the SEC Tournament.
2. Syracuse - East (Boston)
Boston is closer to Syracuse than any regional site, so the Orange get their first choice.
3. North Carolina - Midwest (St. Louis)
Of the two remaining regions, St. Louis is the closer site to Chapel Hill. It is possible that the committee could put Kentucky in St. Louis in order to put North Carolina in Atlanta, saying that it would minimally affect Kentucky's travel and substantially help North Carolina's, though precedent for this is unclear. We'll keep it simple.
4. Kansas - West (Phoenix)
No teams on the top several seed lines claim the West as their natural region, so the fourth No. 1 seed will almost certainly be shipped to Phoenix.
In this scenario, the Final Four pairings will be South vs. West and East vs. Midwest. (I'm not clear why the "making best effort" part is in there. I can see no other bracket principles that conflict pairing 1 vs. 4 and 2 vs. 3.)
The committee will then place the No. 2 seeds in each region in true seed list order.
This is when several of the bracketing principles can come into play, including:
Each of the first three teams selected from a conference shall be placed in different regions.
Conference teams shall not meet prior to the regional final unless a ninth team is selected from a conference. If the committee is unable to reconcile the bracket after exhausting all reasonable options, it has the flexibility to waive this principle to permit two teams from the same conference to meet each other after the second round.
5. Ohio State - Midwest (St. Louis)
St. Louis is slightly closer than Atlanta to Columbus, and there are no conflicts yet for a Big Ten team, so there they go.
6. Michigan State - South (Atlanta)
Michigan State would also prefer St. Louis, but the Buckeyes have already claimed the Jones Dome. All four Big 10 teams claim St. Louis as their closest and most "natural" region, so there is plenty to play for this weekend even if the conference yields no 1 seeds.
7. Duke - West (Phoenix)
8. Missouri - East (Boston)
On the first pass, Duke was assigned to the East with Boston as the second-closest region to Durham. That would then leave the West as the only option for Missouri on the No. 2 line, but with Kansas already in Phoenix the Tigers cannot be placed there. We could keep Duke in Boston and move Missouri down to the No. 3 line, but moving a team up or down a line does not happen often for teams in the top 4 lines, so we'll just swap Duke and Missouri. We may need to revisit this later when we assess competitive balance.
The committee will then place the No. 3 seeds in each region in true seed list order.
Additional bracketing principles can come into play on the third line, including:
No more than one team from a conference may be seeded in the same grouping of four in line Nos. 1-4 and 13-16 in a region, unless a conference has four or more teams seeded in line Nos. 1-4. In lines No. 5-12, two teams from the same conference may be placed in the same group of four
9. Marquette - Midwest (St. Louis)
Despite playing the Big East, Marquette claims St. Louis as its closest region. No conference conflicts prevent this.
10. Indiana - East (Boston)
St. Louis and Atlanta are closer to Bloomington, but both have already been claimed by Big Team teams, so the Hoosiers are shipped up to Boston.
11. Georgetown - South (Atlanta)
Syracuse is already in Boston, so Georgetown goes to the next closest site.
12. Michigan - West (Phoenix)
With four Big Ten teams in the field so far, Michigan could be placed in the same region as one of its conference brethren. However, all four are on the No. 2 or 3 lines and could meet before the regional final, which is prohibited. We'll put Michigan in the West region for that reason, but with the last No. 1 and No. 3 seed in Phoenix, competitive balance could be a problem down the road. We may have to come back to this.
The committee will then place the No. 4 seeds in each region in true seed list order.
13. Baylor - Midwest (St. Louis)
Interestingly, no Big 12 teams are yet in St. Louis, so Baylor get its wish. For now. St. Louis has the best team on three of the four lines, so somebody will probably have to move when we assess competitive balance.
14. Wisconsin - South (Atlanta)
The fifth Big Ten in the field means we'll have to be careful again with conference placement as with Michigan. St. Louis is already taken on the No. 4 line, and Atlanta is the next closest region. Michigan State is the 2 seed there, but they wouldn't meet Wisconsin until the regional final.
15. Wichita State - West (Phoenix)
Finally, a fresh conference means no worries about conflicts. The Shockers end up in Phoenix with St. Louis and Atlanta already taken.
16. UNLV - East (Boston)
The only slot left for UNLV is Boston, which unfortunately is the farthest from Vegas of the four regions. All hope is not yet lost for the Rebels, because…
After the top four seed lines have been assigned, determine the relative strengths of the regions by adding the "true seed" numbers in each region to determine if any severe numerical imbalance exists. Generally, no more than five points should separate the lowest and highest total.
Uh oh. Here's how the numbers add up:
Midwest: 30
South: 32
East: 36
West: 38
For now, the Midwest and South regions are more difficult (based on each team's "true seed" number) than the East and West. That means we'll have to do a little tweaking to balance that.
What options do we have? This is where the published guidance from the committee gets vague. We do know that teams ranked higher on the 1-68 seed list generally should get geographical preference:
If two teams from the same natural region are in contention for the same bracket position, the team ranked higher in the seed list shall remain in its natural region.
(By the way, this principle is why I think Kentucky will stay in the South.)
First, let's swap Wisconsin and Baylor to balance the South and Midwest
Having two Big Ten teams on each of the No. 2 and No. 3 lines makes many of the possible swaps impossible. We want to keep Ohio State in St. Louis as its preferred geography, but beyond that we may have to make some changes. We're going to swap the 2 and 3 seeds between the South and West.
Now we have:
Midwest: 31
South: 33
East: 36
West: 36
Five points difference between the lowest and highest. Good enough for now.
In “true seed†order, the committee then assigns each team (and, therefore, all teams in its bracket group—e.g., seeds 1, 8, 9, 16) to second-/third-round sites.
In other words, we need to assign pod sites for each of the 16 teams we've placed in regions. Most in the first several lines get their preferred site.
1. Kentucky - Louisville
2. Syracuse - Pittsburgh
3. North Carolina - Greensboro
4. Kansas - Omaha
5. Ohio State - Pittsburgh
Ohio State is prohbited from the Columbus pod.
6. Michigan State - Columbus
7. Duke - Greensboro
8. Missouri - Omaha
9. Marquette - Columbus
10. Indiana - Louisville
11. Georgetown - Nashville
Georgetown is the first team that wouldn't get its preferred pod site (Pittsburgh). In fact, their first four pod sites are already filled.
12. Michigan - Nashville
13. Baylor - Albuquerque
This is actually the closest site to Baylor, so as long as they are on the third seed line or one of the better four seeds, that's where they should end up.
14. Wisconsin - Albuquerque
15. Wichita State - Portland
16. UNLV - Portland
In Episode II, we'll tackle the remainder of the seed lines. There are fewer restrictions in the 5-12 lines, and generally fewer conference conflicts in the 13-16 lines, so they may not be quite as exciting.