A crazy Sweet 16?

This year saw the first #15 seed, Florida Gulf Coast, advance to the Sweet 16.  In all, it feels like an absolutely crazy year, with one upset after another.  

But is the current Sweet 16 lineup really that much crazier than past years?

If the top 4 seeds in each region advance to the Sweet 16 then the average seeding in the tournament is 2.5.  So, an average seeding higher than 2.5 indicates that a lower seeded team advanced in place of one of the top four in each region.

This chart shows two data points for the last 11 Sweet 16 rounds.  The line in blue is the average seed of the 16 teams playing each year.  The red line marks a hypothetically perfect year...a year in which the 1, 2, 3, and 4 seeds in each region advance to the Sweet 16.

Over the 11 years, the average seed of the Sweet 16 round is 4.35.  From 2007-2009 the average seed decreased significantly, but then increased dramatically in 2010, 2011, dropped a bit in 2012, and then reached an 11 year high this year.  So maybe you aren't imagining things.  There really is a #15 seed in the Sweet 16, and it really is crazy.

Each year the NCAA publishes bracket with 32 teams on each side.  Although the names of the regional have changed depending on the locations, the design of the bracket doesn't.  If I give each bracket a number looking like this I can break down the averages even further.

Remember, the average seed for a 'perfect' region is 2.5.  From 2003-2013 there have been only five 'perfect' regions in the Sweet 16, and two of those five were in 2009.  

So, next year, when you plan your brackets before the tournament starts, you might want to remember this...pick at least one team in the top four of each region to lose in the first or second round.  

This year's West Regional, which appears in this chart as Region 2, had the 2nd highest average seed of the 11 years. 

And FGCU wasn't even playing in the West.  It is is the South, or Region 3 on the chart for 2013.

If I assign a 'bracket position' to each game, numbered 1-16, it looks like the chart to below.

Returning to the idea of a 'perfect region', for each bracket position, there is an expected seed.  And from that we can calculate a variance each year from the expected or perfect seed.  

Over the 11 years, the delta between the team actually sitting in the bracket position and the expected perfect seed, looks like this:











See that bright red -13 on the bottom line?  Yeah, that's FGCU.  

The green zeroes represent bracket positions where the expected team (#1, 2, 3, or 4 seed) advanced to the Sweet 16.  The average number of expected seeds advancing over the 11 years was 9.9.  In 2013, 10 expected seeds advanced.  

Based on that, one has to conclude that FGCU's advance to the Sweet 16, while very Cinderella-ish, is largely responsible for the 11-year high average seed in the Sweet 16 for 2013.  

So, how did your bracket turn out?  Raise your hand if you picked FCGU in the Sweet 16.

Liar.

GBR!