THE POWER RANK

Does Last Season Matter in College Football?

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Plot of Yards Allowed Per Play in College Football

From 2010 to 2011, the correlation coefficient in yards per play allowed by defense was 0.496.

Numbers, especially those spit out of a computer, must pass the stupid test. If you think the results are stupid, then the numbers don’t pass the test.

After four weeks of college football, I was working on rankings that only included games from this year. Here at The Power Rank, we take football statistics like yards per play and adjust them for strength of schedule. But when I looked at the results for defense, Texas Tech had the top ranked defense.

Texas Tech?

The same defense that gave up 39.25 points a game last year, 117th in the nation?

Last year’s Texas Tech defense actually looked better by yards per play, ending the season ranked 75th in our defense rankings. (In the rest of this article, offense and defense rankings refer our calculations that adjust yards per play for strength of schedule.) But head coach Tommy Tuberville just brought in his 3rd defensive coordinator in 3 years. Even with a load of talent, a jump from 75th to 1st is almost impossible.

It doesn’t pass the stupid test.

How to Make The Rankings Better

We use past data to calculate rankings that predict the future. This depends on using variables that correlate from the past to the future. For example, yards per play allowed by a defense in the first 6 games of the season has a correlation coefficient of 0.481 with yards per play the rest of the season. In contrast, fumble recovery rates for a defense have almost no correlation between the first 6 games and the rest of the season. Hence, we look at yards per play but not fumble recovery rates.

But what about last season? Surprisingly, yards allowed per play correlates season to season with a coefficient of 0.496, even larger than the early to late season correlation. We also looked at other statistics, such as points per game and pass yards per attempt, both on offense in defense. In general, the season to season correlations were slightly smaller than the early to late season correlations.

But what’s going on behind these correlations?

During the season, yards per play is affected by injuries and the inherent randomness of football, such as that tipped pass that falls into a receiver’s hands for a long touchdown. Changing the yards gained on a play from 0 to 92 will have a dramatic effect on the game average. These factors make the early to late season correlation coefficient much less than 1.

From season to season, teams can have large turnover in players and coaches. I thought this would lead to a much smaller correlation coefficient. It doesn’t. One reason is the identity of the program. Texas has a huge fan base, lots of money, and a long tradition of recruiting stellar athletes from the Lone Star state. Rice has none of those things.

No perfect rankings early in the season

The strong season to season correlations suggests using last year’s results in this year’s rankings. In fact, we have been doing that so far, using all games last year and counting this year’s games twice. We will continue to do this.

But there are still problems.

For example, Baylor is still the top ranked offense. Given that the Bears lost quarterback Robert Griffin III to the NFL draft, this ranking is most likely too high. However, head coach Art Briles has led successful offenses at both Houston and Baylor. Moreover, senior quarterback Nick Florence has already led the Bears to 7.26 yards per play this year, much higher than the 5.45 average over all FBS and FCS games last season. With only this year’s games, Baylor is the 34th ranked offense due to weak competition. They will probably end the season somewhere in between 1st and 34th.

Last Season Does Matter in College Football

Surprisingly, key football statistics like yards per play correlates from year to year almost as strongly as it does from early to late season. While that certainly affects what games we use in our rankings, it also matters to fans. Reputation, tradition and money matter in college football. These factors don’t change overnight. Consider these 3 programs.

  • Michigan. The Wolverines had 3 horrible years under coach Rich Rodriguez. But in the 23 years before that, Michigan ended each season in the top 25 of our rankings. In the first year of this streak, a guy named Jim Harbaugh started his first game at quarterback. So it shouldn’t be too surprising that Michigan got back to 12th last year under new head coach Brady Hoke.
  • Auburn. The Tigers have almost 2 million fans and pack over 85,000 of them in Jordan-Hare Stadium for home games. Despite the ups and downs of this past decade, Auburn has never finished in the bottom of half of Bowl subdivision teams in our rankings. They won’t fall that low season either, although that won’t make Auburn fans happy with head coach Gene Chizik.
  • Rice. This small private school in Texas, which happens to be my alma mater, just isn’t a very good football program. The Owls have never finished in the top half of teams this decade, not even during their 10-3 season in 2008. Don’t expect much from this program.

Programs don’t change overnight. Keep that in mind as the season progresses.

Is Gene Chizik a good coach? A look at his defensive coordinator positions.

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In a previous article, we asked whether Gene Chizik was a good coach and looked at head coaching positions. Did he run Iowa State into the ground for two years but then get extremely lucky at Auburn with Cam Newton and Nick Fairley to win the national championship in 2010? Or was Auburn’s poor performance in 2011 an inevitable result of losing Newton and Fairley, implying that Chizik will consistently have Auburn in the national championship hunt? In our previous article, we offer an infographic for you to draw your own conclusions.

In this analysis, we looked at a team’s performance relative to how it faired before and after the coach’s tenure. A school’s resources for football remain roughly constant over time. Even T. Boone Pickens couldn’t change Oklahoma State football overnight with his money. Here, we apply this idea to Gene Chizik’s tenure as a defensive coordinator at UCF, Auburn and Texas. Instead of using our team ratings, we apply our algorithm to give a defensive rating that accounts for strength of schedule. Typically, the defensive rating gives how many points the unit gives up against an average FBS offense. However, we shift the rating here so that it gives how many points better the defense is than the average defense. So a rating of +7 in the visual below implies the defense would give up 7 fewer points than the average defense against the average offense.

Is Gene Chizik a good defensive coordinator?

Again, a higher value implies a better defense. So how did Chizik do?

Central Florida. From 1999 through 2001, Chizik worked as the defensive coordinator under head coach Mike Kruczek. While the defense consistently improved during the last 3 years of his tenure, it fell off rapidly after Chizik left for Auburn in 2002. This led to Kruczek’s firing in 2003, paving the way for George O’Leary to take over as head coach. O’Leary is perhaps more famous for lying on his resume, an act that got him fired by Notre Dame after 5 days as head coach. But he has overseen a consistent improvement in defense from 2004 through 2010. UCF’s defense achieved a higher rating in 2010 than in Chizik’s last year as coordinator in 2001.

Over the 16 year period in the visual, UCF never had defenses as good as Auburn and Texas. This is why we evaluate a coach’s tenure relative a team’s performance at the same school. Also, we could have compared a defense to the average defense in the conference. However, the average rating of 12 teams can change significantly from year to year. Instead, we evaluate defenses with respect to a 120 team average.

Auburn. Chizik took over the defense at Auburn under head coach Tommy Tuberville in 2002 and oversaw a rapid rise to excellence. In 2004, Auburn went 13-0 only to be snubbed from the national championship game in favor of Oklahoma and USC. The defense featured future NFL players Carlos Rodgers and Jay Ratcliff and finished with a rating 13.5 points better than average, 2nd best in the country.

Texas. In 2005, Chizik left Auburn to work under head coach Mack Brown at Texas. Chizik served as co-defensive coordinator with Duane Akina. Led by quarterback Vince Young, the 2005 Texas Longhorns went 13-0 and beat USC in an epic national championship game. The defense posted a rating 9.2 points better than average, good for 7th in the nation. According to Wikipedia, this defense had 9 players taken in the next 3 NFL Drafts. Over the next two years, of which Chizik was around for only the first, the defense fell off quite a bit. This led to the demotion of Akina and the hiring of Will Muschamp as coordinator. In Muschamp’s 3 years at the helm, the defensive started strongly in 2008 only to drop in 2010, a performance eerily similar to the 2005-2007 time period.

So is Gene Chizik a good defensive coordinator? We make visuals so you can draw your own conclusions about the data. Please leave us a comment.

For more content, follow The Power Rank on Twitter.

Related Posts:
—Is Gene Chizik a good coach? A look at his head coaching positions.
—Can a defense force turnovers?
—College football rankings.

Is Gene Chizik a good coach? A look at his head coaching positions.

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When Auburn hired Gene Chizik as head coach in 2009, it set off a firestorm of controversy. In the previous two years at Iowa State, Chizik had a 5-19 record as head coach. This angry fan was happy to point this out to Auburn athletic director Jay Jacobs. The fan didn’t even get the memo that one win came against FBS opponent South Dakota State. Moreover, Iowa State lost to lower subdivision opponent Northern Iowa. However, Chizik quickly turned Auburn around. In 2010, the Tigers completed a 14-0 season with a National Championship game win over Oregon. With such contrasting tenures as a head coach, how can we know if Chizik is a good coach?

To answer this question, we’ll use the year end rating given by our algorithm for ranking teams. While we usually use the difference in ratings to give a projected point spread, here we use the absolute value of the rating. This value gives how many points better a team is than the average FBS team. However, we can’t just look at the difference between Iowa State in 2008 (-10.0) and Auburn in 2010 (24.9) and conclude that Chizik improved as a coach. Auburn has vastly more resources for football than Iowa State.

Instead, we look at a coach’s tenure compared with the school’s performance before and after this period. A school’s reputation and monetary resources for football are roughly constant over time. Iowa State will not suddenly turn into the money making machine that is Texas football. Some schools such as Oregon and Oklahoma State have received hundreds of million dollars in donations, but even this infusion of money doesn’t change the football team overnight. Here, we show The Power Rank’s rating for Iowa State and Auburn from 2004 through 2011.

The Power Rank looks at Gene Chizik's tenure at Iowa State and Auburn.

Iowa State had some decent teams under Chizik’s predecessor, Dan McCarney. The Cyclones came within a missed field goal of winning the Big 12 North title in 2005. However, Iowa State dropped off significantly in 2006, paving the way for Chizik’s two rough years in Ames. In defense of Chizik, McCarney didn’t leave the cupboard full of talent. After recruiting top 50 classes from 2002 through 2004, McCarney wasn’t able to replicate this feat afterwards. In fact, Iowa State hasn’t had a top 50 class since 2004, suggesting that Chizik didn’t do much to increase the talent level at Iowa State. Paul Rhodes took over in 2009 and has overseen steady progress in the program over the last 3 years. In 2011, Iowa State upset Oklahoma State, costing the Cowboys a shot at the National Championship game.

At Auburn, Tommy Tuberville led the Tigers to an undefeated season in 2004, a year in which they got snubbed from the National Championship game. This Auburn team ended the year with a 21.9 rating, 3 touchdowns better than the average FBS team. However, the program declined over the next 4 years, leading to Tuberville’s stepping down and Chizik’s hiring. In 2010, Chizik landed the 4th best recruiting class, highlighted by quarterback Cam Newton and defensive tackle Nick Fairley. These two junior college transfers led Auburn to the national title. The TIgers ended that year with 24.9 rating. In 2011, Auburn posted 8-5 record with a bowl win over Virginia. However, The Power Rank assigned them a 3.7 rating, not far above the 2.1 they had in 2008, Tuberville’s last season.

It’s unfair to judge a coach until he’s had 4 years at a school and the opportunity to recruit his own players and install his own system. However, Chizik faces an uphill climb, as 43% of his 2009 and 2010 recruiting signees are no longer with the program. Moreover, both of his coordinators are new this upcoming season.

However, we make visuals so you can draw your own conclusions about Gene Chizik’s coaching abilities. Did a cyclone hit Ames in 2007 that made coaching at Iowa State horrifically difficult? Were there mitigating circumstances that let Utah State almost beat Auburn to open the 2010 season? Please leave us a comment.

For more content, follow The Power Rank on Twitter.

Related Posts:

—Can a defense force turnovers?
—College football rankings.
—College football’s incredibly slow progress towards a playoff.
—The Power Rank featured on KALX Spectrum, the science and technology show on UC Berkeley student radio.

College Football Rankings, Week 11

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Gene Chizik won 5 of 24 games as the head football coach at Iowa State. That kind of record usually gets a coach fired. Dan Hawkins, the recently fired head coach at Colorado, went 7-17 in his last 24 games, notching 2 more wins than Chizik. So it was shocking when Auburn hired Chizik as head coach after his two years at Iowa State. A 5-19 record seems ominous for a coach entering the Southeastern Conference, the league that has won 4 of the last 5 national championships. One fan took things to the extreme, screaming at athletic director Jay Jacobs about not wanting a loser as a coach.

Auburn hired Chizik based on his success as a defensive coordinator in college football. He led both the 2003 undefeated Auburn team that was screwed out of the national championship game as well as the 2005 Texas team that beat USC in an epic national championship game. Last year, Chizik led Auburn to an 8-5 record with a bowl win over Northwestern in his first year. This year, he’s at the helm of a 11-0 team streaking towards the SEC conference title game and possibly the BS Cartel Series (BCS) national championship game. Yet it’s quite easy to forget about the head coach when quarterback Cam Newton gets all the headlines. On the field, Newton has dazzled with his speed of his legs and the precision of his arm. Off the field, there are allegations his father asked for money in exchange for his son’s attending Mississippi State. His father has even admitted to doing it, but he says his son never knew.

Two weeks ago, Auburn was 11th in The Power Rank, much lower than any of the human polls. Our algorithm doesn’t see the superhuman athletic ability of the quarterback but does note the string of close wins. Since then, Auburn handily beat a good lower division Chattanooga team (104 in The Power Rank) and pulled away from a strong 35th ranked Georgia team. But while Auburn is 5th in the Power Rank, their next opponent Alabama is right behind in 6th, a mere 0.61 points behind. Playing on the road in Tuskaloosa, Auburn should be the underdog in the Iron Bowl against Alabama in two weeks.

1. Oregon, 10-0, 41.05
2. Boise State, 9-0, 32.86
3. TCU, 11-0, 32.38
4. Stanford, 9-1, 29.44
5. Auburn, 11-0, 27.63
6. Alabama, 8-2, 27.02
7. Ohio State, 9-1, 26.55
8. Virginia Tech, 8-2, 25.69
9. Nebraska, 9-1, 24.87
10. USC, 7-3, 24.76
11. Arkansas, 8-2, 24.26
12. Nevada, 9-1, 24.25
13. California, 5-5, 23.92
14. Wisconsin, 9-1, 23.82
15. South Carolina, 7-3, 23.23
16. Arizona State, 4-6, 23.08
17. LSU, 9-1, 22.92
18. Oklahoma State, 9-1, 22.66
19. Iowa, 7-3, 22.62
20. Missouri, 8-2, 22.53
21. Miami (FL), 7-3, 22.03
22. Oregon State, 4-5, 21.49
23. Oklahoma, 8-2, 21.46
24. San Diego State, 7-3, 20.75
25. Arizona, 7-3, 20.49