The predictive power of the preseason AP poll

preseason_AP_cbb_2013Kentucky started the season #1 in the preseason AP poll in 2013.

Then John Calipari’s young Wildcats struggled during the season, losing 10 games along the way. They dropped out of the AP poll entirely by the end of the season.

However, Kentucky found their stride in the tournament. As an 8 seed, they beat Louisville and Michigan in the regional final to advance to the Final Four.

Could we have learned something from the preseason AP poll? Can the opinion of sports writers months ago tell us something about post season play?

Quite surprisingly, the answer is yes. Research shows that the higher ranked team in the preseason AP college basketball poll wins 72% of tournament winners, the same win percentage as the team with the higher seed in the bracket.

The aggregate opinion of sports writers does a good job evaluating the potential of each team. Kentucky is a prime example, as Calipari brought in one of the most highly touted recruiting classes ever.

What about college football?

My own research shows the same predictive power for the preseason AP football poll.

From 2005 through 2012, I looked at how often a higher ranked team in the preseason poll beat a lower ranked team in a bowl game. I assumed a ranked team would beat an unranked team, but didn’t make a prediction between two ranked teams.

The preseason AP college football predicted 59.8% of bowl game winners (125 of 209). The poll made a prediction in 79% of these games. Remember, this poll comes out before any college football games have been played.

To put this accuracy in perspective, let’s compare it with the Colley Matrix, one of the computer polls in the old BCS system. Given the game results of all college football games before bowl season, the Colley Matrix predicts the winner of 55.1% of bowl games (146 of 265).

During the season, the AP poll loses its predictive power because it reacts to strongly to wins and losses. The higher ranked team in the poll just before bowl season wins 57% of bowl games (106 of 186). This poll makes a prediction in 70.1% of bowl games (186 of 265).

I presume the AP college basketball poll also loses its predictive power as the season progresses.

With only hundreds of games, the uncertainty in these win percentages is about 3%. This implies a 2 in 3 chance the actual accuracy of the Colley Matrix is between 52% and 58%. So while we can’t say with certainty that the preseason AP college football poll is more accurate than the Colley Matrix, it does seem likely.

Will Kentucky beat Wisconsin in the Final Four?

Kentucky excels in two areas: offensive rebounding and getting to the line. Julius Randle, the best college basketball player not named Jabari Parker, leads this attack. He is a physical presence with soft hands to finish around the basketball.

However, Kentucky does not shoot the ball well. They shoot 33% from 3 point range, worse than the Division I average. However, Kentucky has found a hot streak in the tourney, going 8-18 against Wichita State and 7-11 against Michigan. Can this continue?

Wisconsin has the 4th best offense by my points per possession adjusted for strength of schedule. Seven foot center Frank Kaminsky has been a beast the entire tourney. He has hit 3 point shots as well as scored around the basket. As a team, Wisconsin shoots 38% from 3.

However, I’m concerned about their point guard play. Traevon Jackson wanted to be the hero against Arizona. On 3 possessions down the stretch, he ran a pick and roll with Kaminsky and then ignored his dominant center in the post against a guard. Sheer stupidity.

My teams rankings, which do not consider the preseason AP poll, predict a Wisconsin win by 1.8 points. This implies a 55% win probability over Kentucky.

Billy Donovan is a bad tournament coach

billy_donovan_mopyFlorida hired Bill Donovan as coach in 1996. But ten years into his tenure as coach, his tournament record looked poor. Check out this five year stretch of appearances.

  • 2001, lost in 2nd round as a 3 seed
  • 2002, lost in 1st round as a 5 seed
  • 2003, lost in 2nd round as a 2 seed
  • 2004, lost in 1st round as a 5 seed
  • 2005, lost in 2nd round as a 4 seed

You may remember their first round game in 2002. Creighton guard Terrell Taylor hit a cross over, Jordanesque jumper to pull off the 12 over 5 upset.

You can hear the pundits right now as the Gators entered the 2006 tournament.

“Billy Donovan isn’t a good tourney coach.”

“He just doesn’t get his players ready for the moment.”

“Look at how he underperformed the last 5 years as such a high seed each year.”

Florida won consecutive national titles in 2006 and 2007. The pundits shut the fuck up.

The curse of small sample size

You should never make judgements on coaches in a small sample size of tournament games. Florida played 158 games over those 5 years and won enough games to never get seeded lower than 5th. How can you restrict your judgement of Billy Donovan to 5 of those games?

A naive athletic director might have fired Billy Donovan after 2005. Each year, other athletic directors make hires based on success in the tourney, such as Andy Enfield at USC after his run with Florida Gulf Coast last season.

So next March, you’ll hear all kinds of talk about how Michigan State’s Tom Izzo is a great tournament coach. His Spartans just lost an Elite 8 game to Connecticut, a game no thought they should lose.

Next March, you’ll hear even more chatter about how Pittsburgh’s Jamie Dixon stinks it up in the tourney each year. However, Dixon consistently fields good teams at Pittsburgh. They will break through one of these years.

Here’s the truth: Tom Izzo and Jamie Dixon are both great coaches. So is Billy Donovan.

Can Florida win the Final Four in 2014?

After 3 straight years of failures in the Elite 8, Florida advanced to the Final Four this season. It’s not his most talented team. The most highly touted NBA prospect, Chris Walker, barely plays after missing time early this season.

But the Gators bring the defense every game, ranked 2nd in my efficiency rankings that adjust points per possession for strength of schedule. Point guard Scottie Wilbekin gets all the headlines, but watch out for his back court mate Michael Frazier, a 45% shooter from 3 point range.

Their opponent Connecticut also brings the defense, ranked 11th in my efficiency rankings. On offense, point guard Shabazz Napier runs the show, but watch out for their shooters. They don’t take a lot of 3 point shots, but they hit 39% of them. Niels Giffey was hitting over 50% of his 3 pointers until he went 0-5 against Michigan State. Connecticut needs him or DeAndre Daniels to hit some shots to knock off Florida.

Florida has a 66% chance to beat Connecticut (predicted spread of 5.5).

How safe is Warren Buffett’s $1 billion from a perfect bracket?

buffett_screenshotVery safe.

I got interested in the numbers behind a perfect bracket when I saw the existing analysis. A 1 in 128 billion chance for you to pick a perfect bracket? Exactly what assumption does this make?

And no one had looked into the odds that any one of 15 million entrants wins the $1 billion prize. To me, that’s the more interesting question.

Under the most pessimistic assumptions possible for Buffett, he has a 1 in 590,000 chance to lose his money. In reality, the likelihood is more like 1 in a million or more.

To read my analysis, which has very few numbers and references to Floyd Mayweather and the Khardashians, head over to Grantland.

In case you were wondering, I’m not filling out a bracket. There’s no chance of winning, and I don’t want Quicken Loans spam filling up my inbox.

The odds for the 2014 Big Ten Tourney

My buddy Mark Elsesser tweeted me yesterday about whether Nebraska at 16 to 1 odds to win the Big Tourney had value.

Nebraska has been hot lately, with wins over Michigan State and Wisconsin towards the end of the conference schedule. However, my rankings, which consider all games from the season, only rank them as the 8th best Big Ten team.

I calculated the win probability for the Big Ten tourney, which starts in a few hours.

1. Wisconsin, 22.6%
2. Michigan, 20.1%
3. Michigan State, 17.7%
4. Ohio State, 13.7%
5. Iowa, 10.6%
6. Nebraska, 5.5%
7. Minnesota, 3.1%
8. Indiana, 2.9%
9. Illinois, 1.9%
10. Penn State, 0.9%
11. Purdue, 0.8%
12. Northwestern, 0.2%

Nebraska has the benefit of a first round bye, making the 8th best team have the 6th highest win probability.

The Vegas odds of 16 to 1 equates to a 5.8% win probability, which is consistent with my calculation of 5.5%.

Overall, the tourney looks wide open. Five teams have a greater than 10% chance to win.

Will a 16 seed ever beat a 1 seed?

nova_morrisIt will happen. Maybe not this year, maybe not next year, but a 1 seed will fall to a 16 seed.

Just look at the last two seasons. Syracuse needed help from the referees two seasons ago to escape UNC Asheville. Southern took Gonzaga down to the wire before Kevin Pangos hit some shots to put the game away.

Numbers also support the claim that a 1 seed will topple in their first game. Let me explain.

Interactive bracket with win probabilities

Based on CBS’s bracket projection, I used my college basketball rankings to calculate the win probabilities for each team. This interactive bracket displays these 416 numbers, which include the chance that each team advances through each round.

Hover over each game to see the chance that each team has to win that game. Hover over each team to see their probability to advance through each round, as shown for Villanova in the visual.

Clearly, this bracket is more useful after Selection Sunday, a short 10 days from now. However, let’s look at the likelihood that any of the 4 one seeds go down.

The numbers behind the 1 vs 16 matchup

My win probabilities imply a 34.7% chance for 16 seed to beat a 1 seed in the CBS bracket projection.

This chance is too high. My win probabilities for games with big point spreads tend to favor the underdog too much. For example, Florida Gulf Coast has a 8.7% chance to upset Arizona. It’s probably more like 4% (there is no math behind this number).

However, consider the hypothetical world in which each 1 seed had a 99% chance to win over a 16 seed. The next 10 tourneys will feature 40 such games. To determine the chance that all 40 top seeds win, you take 0.99, multiple by 0.99, and do this another 38 times to account for all 40 games.

The answer? There’s a 66.9% chance all 40 teams win. This leaves a 33.1% chance that at least one 16 seed wins a game.

I have a long standing bet with a friend over this. We bet a six pack of beer over whether a 1 seed would lose to a 16 seed over the next ten years. (Neither of us remember when we made this bet, so the 10 years end after I win.)

Based on the 33.1% chance above, you may think I got the bad end of the deal. However, most 16 seeds have a much better than 1% chance to pull the upset. Even if you assume a 2% win probability, my chance of winning over the 10 year period goes up to 55%.

Can this be the year?

Robert Morris against Villanova

The CBS bracket pits 1 seed Villanova against 16 seed Robert Morris, a game that should excite any fan that lives all year for the upsets of the first 2 days of the tourney.

Villanova is overrated as a 1 seed, as my team rankings place them 8th. Moreover, they shoot 3 point shots on 46% of field goal attempts, 6th most in the nation. Live by the 3, die by the 3.

In addition, Robert Morris shoots 39% from 3 point range. If they get hot while Villanova goes cold, I could be collecting my six pack.

Of course, it’s too early to get excited with this mock bracket. Villanova could drop from a 1 seed if they lose early in the Big East tournament. Robert Morris must win their conference tournament to even make the field.

The likelihood of a 16 seed upset is higher if the best teams in the lower ranked conferences win their tournament. For example, if a team like Savannah State, ranked 294th, wins the Mid-Eastern conference tourney, then they would be a 16 seed in the tourney. A team that my numbers consider 7.5 points worse than average will not help my chances of a 1 seed upset.

But one of these years, a 16 seed will beat a 1 seed. You heard it here first.