The Curse of the 8th seed

Submitted by jbibiza on March 16th, 2011 at 4:54 AM

I know that there was a thread a few days ago lamenting the challenge of the #8 seed, but this article in the New York Times is a wonderfully comprehensive look at why the 8 or 9 seed is a big disadvantage for teams seeking to get past the second round.  For those of you who love stats and charts (the Diary Mafia of bits and bytes) this is gold.

http://fivethirtyeight.blogs.nytimes.com/2011/03/15/when-15th-is-better-than-8th-the-math-shows-the-bracket-is-backward/?hp

Comments

TorontoBlue

March 16th, 2011 at 10:02 AM ^

When doing my brackets i was surprised how much easier the Anaheim games shook out compared to two Charlotte matchups.  If we can get out of Charlotte, the road gets a little smoother which is the opposite of what you would expect.

Wisky got to the Final Four in 2000 as an unheralded 8th seed so it can be done.

GO BLUE!

OysterMonkey

March 16th, 2011 at 8:23 AM ^

Seed Total wins Exp
1 3.43
2 2.43
3 1.84
4 1.47
5 1.17
6 1.21
7 0.83
8 0.65
9 0.59
10 0.65
11 0.49
12 0.52
13 0.25
14 0.17
15 0.04
16 0

This is based on historical performance, so if we think that 10 seeds are really a little worse on average than 8 seeds, the 10 seed line is a little more advantageous. 12 has a similar (although less dramatic) advantage over the 11.

bigmc6000

March 16th, 2011 at 9:03 AM ^

I'm at a bit off a loss on this one - it seems to take a computational representation of the results rather than actual results because, as we all know, no 16 seed has ever advanced to the 2nd round.

 

Is there a site that takes all the results and condenses them down to %'s based on historical results rather than mathmatical attributes?

Ch125

March 16th, 2011 at 9:49 AM ^

Yes Irving is talented. Yes he makes duke deeper. But he hasn't played with them all year. Chemistry on the court is a big cotributor to winning. Him playing does not necessarily doom us in the second round, as He might not even play more than 10-15 minutes. We have played tight games with the best in the country, we are due to win one arent we?

ijohnb

March 16th, 2011 at 9:50 AM ^

come back  I never find it beneficial for a team to through a wrench in their plans last minute.  Unless that has been the plan all along, that is.  Not a good idea to throw in that extra ingredient just before cooking just cuz you can.  I think Coach K would be making a mistake if he does that.

ijohnb

March 16th, 2011 at 9:47 AM ^

it is hard to get past the second round with an 8 seed because you end up playing, say, Duke in the second round.  When there was a big difference between the 8-9 matchups and the 7-10 matchup, being a 9 or lower seed proved to be an advantage to get to the second round because you avoided the 10 which put you against a 7 and I am old enough to remember when there was a much bigger difference between a 7 seed and an 8 seed.  Now basically 5 -12 seeds are = and getting a 8 or 9 just means that you have a better chance of getting smacked around in the 2nd round.

Not going to matter though, Michigan will take Duke.  Duke's personnel does not exploit Michigan's weaknesses, they are a good mathcup for us if we get by Tennessee (which I think is a lot more likely than most national commentators think).  Texas, on the other hand, in the words of a twenty something texter, YIKES.

joeyb

March 16th, 2011 at 9:55 AM ^

If your goal is to get to the sweet 16, then you probably shouldn't be in the tournament. It doesn't matter when you play them because they are either mortal and we can beat them, or you are going to lose to them at some point anyway. If anything, facing them earlier is better because we have a better chance at facing them without their star player.

dahblue

March 16th, 2011 at 10:07 AM ^

While I was bothered by the 2nd round matchup at first, I now think...fuck Duke.  Let's get out there and see what happens.  The only downside is the possible media slurping over Tom Izzo if he pulls an "historic" upset over a weak 7 seed in UCLA and then a "magical" win over 4-seed-in-2-seed's-clothing, Florida.  Here's to hoping for a State loss in the first round and making Bobby Hurley cry when we beat the White (oops, I mean Blue) Devils.

Blue boy johnson

March 16th, 2011 at 1:41 PM ^

Posters on here are way too little brotherish regarding MSU hoops. MSU is not built for  a long tourney run, they only have one guy who can score and they don't seem to be enjoying themselves at all. More than likely UCLA puts them out of their misery. This MSU team in no way approximates last years tourney model.

umfan

March 16th, 2011 at 10:13 AM ^

Obviously it's tough because you play the 1 seed in the next round. But once we get past the Blue Devils I'd say we're lookin pretty good

UM in VA

March 16th, 2011 at 10:18 AM ^

The writer talks about a bunch of ways to make it more fair for the 8 seed but he never mentions that changing anything will take advantage away from the higher seeds.  The point of any playoff seeding is to give the highest seeds the easiest road as a reward for being the highest seed.  The 8 seed getting screwed is just a byproduct of that.

stubob

March 16th, 2011 at 10:24 AM ^

Since the only thing that matters is the money, does the payout change depending on how many games you play? Do they all get the same amount just for showing up, or does the teams that make it farther get a larger share?

jtmc33

March 16th, 2011 at 11:36 AM ^

Interesting... but obviously wrong when you compare actual history with the math:

I remember No. 8 seeds Providence, UNC, and Ohio State making the Final 4 in the past (let alone the Sweet 16) and know that zero #16 seeds have ever won a game.  However, according to "the charts" in the article the actual history of what has occurred is a mathamatical improbablity. 

 

cheesheadwolverine

March 16th, 2011 at 12:42 PM ^

The charts are an attempt to isolate the role of the seed for a given team.  As such they are not actually reflective of the probability that a given seed will make it a long distance because they ignore the fact that an eight seed is better than a 13 seed and therefore is more likely to succeed even with a difficult schedule.

Everyone Murders

March 16th, 2011 at 1:02 PM ^

Maybe someone more numerate than me can explain why, according to the article, the combined likelihood of the No. 8 seed and the No. 9 seed advancing past the first round exceeds 100%.  Since they always play one another (with - of course - no ties), it seems axiomatic that the percentages should add up to 100%.

OMG Shirtless

March 16th, 2011 at 1:50 PM ^

Let me be very clear about what this chart means. It is not the chance that a No. 1 seed, for example, will win its first round game. Instead, it is the chance that a decent team with a power rating of 85 would win the game if it took the place of the No. 1 seed in the bracket — the “Let’s Make a Deal” Scenario. Our hypothetical team — let’s call it Arizona — would have about a 90 percent chance of winning if it were seeded as a No. 1, because it would face a weak No. 16 seed. But the same team would have just a 15 percent chance of winning as a No. 16 seed, since it would play a No. 1.

http://fivethirtyeight.blogs.nytimes.com/2011/03/15/when-15th-is-better…

It has something to do with the power rankings they assigned to each seed.  Here's how they assigned power rankings.

 

The Simple Version – First, we create a power rating for each team. The power rating is an aggregation of four computer ratings and two human ratings, all of which have performed well at predicting tournament games in the past:

Objective (computer) ratings:

a) Jeff Sagarin “predictor” ratings; b) Ken Pomeroy Pythagorean ratings; c) Joel Sokol LRMC rankings; d) Sonny Moore power ratings.

Human ratings:

e) Tournament seeds; f) The Associated Press preseason poll. (The rationale for accounting for preseason expectations is explained here.) –

Next, this power rating is adjusted based on three factors: injuries (and other types of player absences like suspensions), the geographic location of the game, and (after the first round) a team’s performance in tournament games so far. –

Finally, by comparing two teams’ power ratings, we can estimate the likelihood that any team in the 68-team field will beat any other in any given game. This allows us to play out the rest of the tournament and estimate the probability that any team reaches any subsequent round, or wins the national championship.

http://fivethirtyeight.blogs.nytimes.com/2011/03/14/how-we-made-our-n-c…

They're interesting articles.

Everyone Murders

March 16th, 2011 at 4:34 PM ^

I pasted the graph from the NYTimes article.  I think OMGShirtless is zeroing in on the point: i.e., that there's an assumed power rating that only gets ascribed to the seed under consideration.  So they do an analysis for an 8 seed with an assumed power rating of 85, and then do an analysis for a 9 seed with an assumed power rating of 85.  

That seems to be what is yielding the facially counterintuitive results on the graph.