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Florida basketball: Mind the S-curve and seed line, not the polls

College basketball polls are about as close to pointless as it gets. The best way to figure out a team's standing is is by looking at the S-curve.


When Butler beat Gonzaga at home on Saturday, in the best game of a great day of college basketball, I IMed one of my friends, a college basketball diehard, suggesting that it might have been "worth a seed line." And then I stopped myself and realized how deep into the jargon of college basketball one has to get to understand seed lines, or the S-curve — the things every fan, not just Florida's, should be paying attention to instead of polls.

Florida's ranked No. 7 in the USA TODAY Coaches Poll and No. 8 in the AP Top 25 this week, as big wins over Texas A&M and Missouri helped move them past Gonzaga, Minnesota, and, in the USA TODAY poll, Indiana. Guess what? That doesn't matter one bit. College basketball's polls are the opinions of writers and coaches, but the opinions of writers and coaches do not factor into the process by which teams are selected and ranked for the NCAA Tournament.

That process remains, in 2013, more like the process for selecting the next Pope than anything transparent. But it shouldn't be a public secret, because the methodology isn't really a secret. Here's the Wikipedia explanation, which I use because it's pretty readable:

Though the brackets only feature the seed numbers 1-16 in each region, the committee assembles an S-curve of teams seeded from 1-64. In theory, the teams 1-4 on the seed list will all be No. 1 seeds (the No. 1 "seed line"), 5-8 will be No. 2 seeds (the No. 2 seed line), and so on; however, bracketing rules often lead to some deviation from this. The S-curve is most important for keeping each region balanced, the ideal being that each region will be equally strong. For example, the committee will try to ensure that the number 1 team on the seed list, the national No. 1 seed, will be in the same region as the weakest No. 2 seed. The committee tries to ensure that the top four seeds in each region are comparable to the top four teams in every other region.

For example, if one region has the best No. 1 seed (No. 1 overall), the weakest No. 2 seed (No. 8 overall), the best No. 3 seed (No. 9 overall), and the weakest No. 4 seed (No. 16 overall), its seeds add up to 34, the ideal number. But if a region has the best team for every given seed, its seeds would add up to 28, and a region with the weakest team in every seed would add up to 40, making the two regions very unbalanced. It is extremely unusual that an at-large bid can be lower than a No. 12 seed, but it has occurred, most recently with BYU and Iona being No. 14 seeds in the 2012 Tournament. While the seeds are almost never perfectly balanced throughout the four regions, the committee strives to ensure that they differ from each other by only a few points. The process is identical for the women's tournament, with the exception that seeding occurs to 64.

The selection committee uses a number of factors to place teams on the S-curve, including record, strength of schedule, the Ratings Percentage Index (RPI), and a team's overall performance in recent games. The RPI rating is often considered a significant factor in selecting and seeding the final few teams in the tournament field, though the selection committee stresses that the RPI is used merely as a guideline and not as an infallible indicator of a team's worth.

That's a lot of words, but it boils down to this:

  • The selection committee creates a ranking of teams from 1-64.
  • It attempts to create brackets by snaking down the S-curve and putting the best of one seed line with the worst of the next and so on.
  • The S-curve is really a table with four columns (each an "ideal bracket") and 16 rows (or the seed lines), and is read left to right, then right to left, then left to right, and so on.
  • Understanding that is really, really simple, and should help break you of the addiction to the little numbers next to teams' names in stories and on ESPN broadcasts, because they really, really don't matter.

    Florida's currently a No. 2 seed in the latest bracketology efforts from SB Nation's Chris Dobbertean, ESPN's Joe Lunardi and's Andy Glockner. Florida is in the East and in No. 1 seed Duke's regional according to Lunardi and Glockner, and is the No. 2 seed in the Midwest (No. 1: Michigan) in Dobbertean's. (Side note: I would love an Elite Eight matchup with Duke, and so would the media, given that Erik Murphy is a Gator and Alex Murphy is a Blue Devil)

    I think we can reasonably assume that Duke has the best résumé in the country — Mike Krzyzewski's bunch has wins over Louisville, Minnesota, and Ohio State, only the latter coming at home — and so is the No. 1 team on most projected S-curves at the moment. That, and Duke getting a regional that ends in Washington, D.C., suggests to me that Dobbertean, Lunardi and Glockner are constructing a bracket that has Duke as the overall No. 1 seed, which makes sense given the Blue Devils' lone loss and No. 1 spot in most estimates of RPI. (There is another longish piece to be written about RPI, but I'll save it.) Correspondingly, Lunardi and Glockner likely think Florida is No. 8 on the S-curve (Update: Glockner thinks he had Florida No. 7), last on the No. 2 seed line, or close enough to put the Gators in the No. 1 overall seed's bracket. We know Dobbertean has Florida No. 6 because he's got his brackets ordered, and has Michigan third among No. 1 seeds.

    That range makes sense, considering Florida's No. 7/8 perch in the polls, but it's easier to match poll position to S-curve slot near the top of both rankings: There's less disagreement about the No. 1 or No. 5 team, usually, than there is the No. 15 team. And the further down we go, the more we run into discrepancies: Kansas State (which has beaten Florida, Oklahoma State, and Oklahoma, and no one else of note) was No. 11 in the AP poll and No. 13 in the USA TODAY poll, but is a No. 5 seed according to both Dobbertean and Glockner, and a No. 6 according to Lunardi; Miami, No. 25 in the AP poll and unranked according to the coaches, is No. 4 according to Dobbertean and Glockner, and No. 5 according to Lunardi ... because Miami's probably in the top five in RPI at the moment, having played well against a rigorous schedule.

    But that's because those writers have no fealty to the polls, which, again, don't factor into the selection committee's work. They're looking at RPI, record, and record against top opponents, and they're trying to predict what the selection committee will do. Fans would do well to remember that, especially Florida fans, because the Gators are going to go from being underrated in the polls to overrated in them if teams ahead of them start losing big games while Florida continues trouncing the SEC.

    I will have more later this week on what Florida fans should look for going forward from the Gators (and why it's important to pay attention to Florida's past and future opponents), but, for now: Are you okay with Florida being a No. 2 seed? What teams do you not want Florida to see in its regional? Do you have any other questions you want answered about the NCAA Tournament selection process?