Tuesday, July 14, 2009

Who Will Go Undefeated This Year?

Going undefeated in college football, even in a season of only 12 games, is extremely difficult. Rare is the season like 2004 when three teams finished undefeated (Auburn, Southern Cal, Oklahoma). More plausible is a scenario like 2007, when LSU got to the championship game with two losses (although to be fair, that was the first time that had happened).

To illustrate the improbability, let's take a quick look at a Top 10 team (according to Steele) expected to be favored in up to 11 of 12 games. Just because Notre Dame could or should win all its games doesn't mean it will. Remember that a team with a 90% probability of winning each of 12 games has a 28% chance of going undefeated, not 90%. That's because all 12 independent outcomes have to occur a certain way, meaning the math is .90 x .90 x.90 etc. (Statistics again on this blog. Who knew?)

I assigned an estimated probability of victory to each of ND's games. You can quibble over the margins but the point remains: despite being the likely favorite against everyone except Southern Cal, ND has only a 2% chance of an undefeated season, not 73%.

Likelihood of Going Undefeated
Game NumberChance We'll WinOpponent
20.65at Michigan
30.80 Michigan State
40.75at Purdue
70.55Boston College
80.90 Washington State
90.85 Navy
100.60at Pittsburgh
120.85 at Stanford
Average: 0.7333Season Total: 1.98%

But that's just an example to ask the question: who will go undefeated in 2009? Probably no one, if history is a guide, but who has a chance? Phil Steele has an idea: he ran the numbers through his Power Ratings system. (No, I don't know how he calculates the ratings--it's part of the proprietary magic that makes Steele Steele.)

For context, look at Phil's list of potential undefeated in 2008: Florida, Ohio State, Southern Cal, Oklahoma, Georgia, Missouri, West Virginia, South Florida, Clemson, Utah, BYU, Virginia Tech, Tulsa, Ball State. You might say that any schmuck could look at the Gators, Sooners and Trojans and say there's a chance they could run the table. (The fact they did not says more about the truth of my first paragraph than failings of the predictions.) What about a 10-4 Tulsa team (in 2007) that lost 3 of those 4 by 19+ points? What about a 7-6 Ball State team that did in fact go 12-0 before falling in their conference championship? How about Utah improving from 9-4 to 12-0?

In the 2009 magazine, Phil lists 17 schools that he thinks has a chance (i.e., one of more of his Power Ratings says so) to go undefeated: Florida, Texas, Southern Cal, Penn State, Pittsburgh, Notre Dame, Ole Miss, Oklahoma, Ohio State, Virginia Tech, Alabama, California, Illinois, Rutgers, Texas Christian, Boise State, Southern Mississippi.

We can winnow that 17 down to a max of 10 possible undefeateds:
  • Ole Miss and Alabama play each other; a perfect SEC West champ would face an undefeated Florida in the conference title game. (minus 2)
  • Texas and Oklahoma face off. (minus 1)
  • One will be eliminated from the Southern Cal/ND/Cal mix, because USC plays both. (minus 1)
  • The three Big Ten teams play round robin. (minus 2)
  • Pitt and Rutgers play each other. (minus 1)
And Virginia Tech plays 'Bama to start the season, so that could get it down to nine. And it's hard to see Cal AND the Irish both beating Southern Cal, so you're down to eight, and so on.

Of course, the vagaries of injuries, turnovers and last second field goals make going undefeated nearly impossible. Phil doesn't say they will, only that they could. But keep an eye on these teams to see if they can pull it off.


Kelly said...

Also, you can safely cross out Virginia Tech and Oklahoma. They both play Nebraska.

Anonymous said...

if you think they have a 50 percent chance of beating southern cal your dreaming and seriously mistaken.

Jim Ashburn said...

Interesting numbers. My list (http://atomicfootball.blogspot.com/2009/08/2009-undefeated-regular-season.html) of 13 averaged 2.08 losses each while Phil's 17 averaged 3.06 losses (through 12/19). His top 13 actually faired worse (3.31) since TCU and Boise missed that cut.

The only team on my list that missed Phil's was Iowa (10-2). Those on Phil's list that missed mine were Notre Dame (6-6), Virginia Tech (9-3), Illinois (3-9), Rutgers (9-4), and Southern Miss (7-5).