Wednesday, October 26, 2005

Delta Force

In separating the wheat from the chaff in college football, one useful tool is a team's delta points. Determining the delta points for a team is not rocket science. Delta points are simply net points. That is, points scored minus points allowed. If team has positive delta points, they have scored more over the course of a season than their opponents. If they have negative delta points, they have been outscored over this same span. Teams that play for the national championship not only win all their games (most of the time); they also dominate their opponents. To demonstrate this fact lets look at the delta points for each team that played for the BCS national title (plus the co-champion Southern Cal Trojans from 2003), and their average scoring margins per game. All data is before the BCS title game.

Tennessee: 235 19.58 per game
Florida State: 247 20.58 per game

Florida State: 238 21.64 per game
Virginia Tech: 339 30.82 per game

Oklahoma: 276 23 per game
Florida State: 386 32.17 per game

Miami: 372 33.82 per game
Nebraska: 260 21.67 per game

Ohio State: 220 16.92 per game
Miami: 286 23.83 per game

LSU: 314 24.15 per game
Oklahoma: 394 30.31 per game
Southern Cal: 281 23.42 per game

Southern Cal: 291 24.25 per game
Oklahoma: 269 22.42 per game

First some caveats:
1. Scoring margin is not the end-all statistic. It does not take into account strength of schedule. Therefore, Virginia Tech in 1999 and Miami in 2001, are not as dominant as their 30+ scoring margins would indicate as they dominated a relatively weak Big East.
2. Scoring margin does a very poor job in predicting the head-to-head winner of the BCS championship game. Teams with the higher scoring margin are 2-5 in the 7 BCS title games. Again this likely relates back to schedule strength not being accounted for.

So, what can we conclude from this data? Basically, a team needs to outscore its opponents by at least 16 points per game to earn a shot at the national title. Contrary to popular belief, even Ohio State in 2002 had several blowout wins to add to their scoring total. Although they played 6 games decided by 7 points or less, they still blitzed some good teams (a 24 point win over 9-5 Texas Tech, an 18 point win over 10-3 Washinton State, and a 31 point win over 8-5 Minnesota). Now lets look at 2005 data and see if we can determine which undefeated (and 1-loss) teams are for real, and which are just pretending. It should also be noted, that each teams schedules (with the exception of Texas and possibly Southern Cal) will only get more difficult so their scoring margin per game will likely go down.

Undefeated Contenders:
Texas: 225 32.14 per game
Southern Cal: 192 27.43 per game
Virginia Tech: 201 28.71 per game

The usual suspects here. The consensus Top 3 have been dominating opponents so far.

Undefeated Pretenders:
Georgia: 120 17.14 per game
UCLA: 119 17 per game
Alabama: 96 13.71 per game

Neither of these teams are likely to go undefeated. Aside from their low scoring margin, Georgia also lost their starting quarterback for the 'Cocktail Party'. UCLA has already won 3 conference games in the final minute or OT. That luck is likely to run dry soon (maybe this week against rejuvenated Stanford?) as their defense has yet to stop anyone. Alabama has seen their scoring margin per game drop from 18 per game before Prothro's injury to a little under 14 in only 2 games. They have also only scored one touchdown since their top wide receiver went down. Will surely fall to either LSU or Auburn if not both.

The 1-loss bunch:
Texas Tech: 188 26.86 per game
Miami: 119 19.83 per game
Penn State: 158 19.75 per game
Florida State: 133 19 per game
Wisconsin: 120 15 per game
Boston College: 100 14.29 per game
LSU: 66 11 per game
Oregon: 87 10.88 per game
West Virgina: 51 7.29 per game

Take Texas Tech's numbers with a grain of salt. If we remove their 2 games against non-Division I competition, they drop down to 14.6 per game. Miami is quietly creeping around and may be the 1-loss team in best shape should two of the Big 3 stumble (they will have a say in whether Virginia Tech makes it through unscathed). Penn State and Florida State are also very good and seem to have recovered from their recent road losses. I'm not sure what to make of Wisconsin. I think their schedule has been relatively easy when compared to the other 1-loss teams. Wisconsin's season will be defined by their November 5th date with Penn State. If they win, they are likely to be Big 10 champs in Barry Alvarez's final season. Boston College is likely to drop from this list as they play at Virginia Tech tomorrow night. LSU is another team I am not quite sure of. Auburn did just enough to lose to them this past weekend and their scoring margin is very low. However, LSU has yet to play any non-conference cream puffs as their other NCAA brethren have thanks to Hurrican Katrina. That will change in the next 2 weekends as they host North Texas and Appalachian State. Oregon's return has been a nice story, but with their low scoring margin and injury to starting quarterback Kellen Clemons, they are likely to lose at least once and perhaps twice more before the season is out. West Virginia is obviously the weakest 1-loss team, as their marquee victory is probably 2-loss Louisville.

Delta points and scoring margin seem to back up convential wisdom. There are 3 teams that appear to be head-and-shoulders above the competition. The last 3 undefeated teams are hanging on by the thinnest of margins either because of inept defenses or injuries to key offensive players. One surprising thing is that the best 1-loss team may in fact be Miami or Penn State instead of LSU.

No comments: