Wednesday, August 20, 2008

The Real Statistical Characteristics of BCS Champions

It’s the Defense, stupid!

After my critique of ESPN’s “analysis” of the commonalities of BCS title winners, I decided to take a look at the real statistical characteristics that make up a BCS champion. Unlike ESPN, I wasn’t looking for any “magic” characteristic and matching number that supposedly decides a champion, rather I was looking for the average national ranking in team statistics, and averages of those statistics. I choose team statistics rather than individual statistics, as I don’t think it makes a significant difference whether a team has a 15 yards per catch receiver or not.

I looked at every BCS title game winner this decade (century, if you will), so our 8 team’s worth of data is more inclusive than ESPN’s last 5 years “analysis”.

The following is the list of statistics, arranged from the highest average ranking to lowest. In this way we can see what statistical measurement the successful teams had in common that ranked highest among their peers in every year since 2000 –

The top 3 highest average ranked categories jump out immediately as defensively oriented, especially Scoring Defense. Over the past 8 years, the eventual BCS title winner has averaged a scoring defense ranked 5.63, and given up only a meager 14.03 points per game. The worst ranking by a team was last year’s LSU Tigers at 17th overall and 19.9 ppg, but that statistic is skewed by the two overtime scorefests in which they participated. LSU in 03’ and Miami in 01’ were 1st ranked in this category.

Pass Efficiency Defense and Total Defense likewise are typically top 10 statistics nationally for BCS winners. The worst in Pass Efficiency Defense over the time period was Ohio State in 02’ (32nd, all others were top 10), and the worst in Total Defense was also the 2002 Buckeyes at 23rd (once again all others were top 10).

Passing Efficiency, Scoring Offense, Rushing Defense and Turnover Margin are all fall within the average top 20 rankings nationally of BCS title teams. After that, the presumed relevance to success becomes less certain. Not surprisingly, Punt Returns and Kickoff Returns don’t appear that important to title winners – very surprisingly passing offense also appears of low importance on a national scale to the eventual BCS Champ (giving somewhat immediate lie to ESPN’s focus on 3000 yards passing as a critical statistic).

In fact when you look at the last 8 BCS winners, not a single one had a passing offense ranked in the top 10 nationally by year’s end. The worst of the time period was Ohio State in 02’ at 92nd nationally, the best USC in 04’ and Oklahoma in 00’ tied at 13th nationally. LSU last year was 58th.

By calculating the standard deviation of ranking for each statistic we can project the range within which 68.27% ( 1 standard deviation) of national champions should rank for each characteristic.

Looking at the chart with Rushing Offense as an example, we can expect that 68% of the time the eventual BCS champion will rank between 9th and 49th nationally, a fairly wide range. However for the more important statistics, like the aforementioned scoring defense, we can expect the BCS winner to rank no worse than 11th overall.

We also see here how irrelevant passing offense has been, as we can expect the eventual champ to range from 14th to 66th. In fact, we can expect that the champ WON’T BE BETTER than 14th, as the top passing offenses usually fail to succeed overall.

So what should we look for in 2008, based on history? Look for a team likely to finish in the top 11 in Scoring Defense, the top 15 in Total Defense, and the top 18 in Passing Efficiency Defense. As for the other statistics, they vary too widely in range to be very predictive. Even for scoring offense, 68% of champion teams need only to be better than 27th nationally.

Who was that last season that met the above defensive ranges? Well LSU did not, but the statistic they failed on, scoring defense, was skewed badly by their overtime games. That aside, teams meeting the top 10 in Scoring Defense, top 15 in Total Defense, and top 18 in Passing Efficiency Defense in 2007 were –

Ohio St.
Southern California
Virginia Tech

An interesting, and mostly successful, bunch. And LSU would be there but for the overtime games.

So if you want to try to project who is going to win the BCS title this year, ignore ESPN’s nonsense, and tell me who will be the top defensive teams. Or, if you like Georgia, do you think the 2008 Georgia defense can improve from their scoring defense in 2007 of 18th nationally to at least 11th, keep their total defense at least as good as last year’s 14th, and really improve their Passing Efficiency Defense from last year’s 36th to better than 18th? If they do all that, the statistics of past winners show they have a fairly decent chance.

1 comment:

chefboyardee said...

Great post. Although it's weird that the only conference with two qualifiers is the ACC. Decent defenses, lousy offenses ?