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Statistically Speaking: Winning the Close Ones

Monday, June 04, 2007

Winning the Close Ones


A team's record in close games is a topic I have examined several times here at Statistically Speaking. Not to beat an old horse, but the off-season is very long, so here's another look. If you want a refresher on the other findings regarding close games, you can read about them here, here, here, and here.

This post will examine how well six different team statistics correlate with a team's record in close games. The sample size for this test is every Division IA team that played at least three close games in 2006 (100 teams). The independent variable is always the team statistic that is being evaluated and the dependent variable is a team's winning percentage in close games.

Turnover Margin

The first statistic we'll examine is turnover margin. Turnover margin can be positive or negative and is simply the number of turnovers a team commits subtracted from the number of turnovers it gains. It is calculated on a per game basis. I am using turnover margin instead of the more familiar (to NFL fans) plus minus ratio because college football teams do not play the same number of games. The best team in terms of turnover margin in 2006 was the Minnesota Golden Gophers. They played 13 games during which they lost 14 turnovers and gained 32. Their turnover margin was +1.38 per game. This means they averaged close to one and a half fewer turnovers per game than their opponents. The worst team in 2006 was the Army Black Knights. They played 12 games and committed 37 turnovers while gaining only 19 for a turnover margin of -1.50.

Turnover margin has a positive relationship with a team's record in close games. This means that as a team's turnover margin improves, a team's record in close games should also improve. However, the relationship is very weak. The r squared value is only .0502 meaning that only about 5% of the variation in a team's record in close games is explained by their turnover margin. The weakness in this relationship is best illustrated by Minnesota. Despite leading the nation in turnover margin, they finished 1-3 in close games.

3rd Down %

3rd down % is the percentage of times a team converts 3rd downs into first downs by picking up the necessary yardage. The NCAA leader in this category in 2006 was the Hawaii Warriors. They converted almost 58% of their 3rd downs into 1st downs (77 out of 133). The worst team at converting 3rd downs was Florida International. The winless Golden Panthers converted 23.5% of their 3rd downs into 1st downs (39 out of 166).

3rd down % also has a positive relationship with a team's record in close games. As a team improves it's conversion percentage it should see improvement in it's record in close games. However, this relationship is even weaker than the one for turnover margin. The r squared value of .025 is less than half that for turnover margin.

3rd Down % Defense

The mirror image of 3rd down %; this is the percentage of times a team prevents their opponent from gaining the necessary yardage to move the sticks on third down. The best team at preventing their opponents from converting 3rd downs in 2006 was the Virginia Tech Hokies. Opponents converted only 27% of their 3rd downs into first downs (50 out of 185). The easiest team to convert 3rd downs on was the Air Force Falcons. Opponents converted over 56% of their 3rd downs into first downs (79 out of 141). The Falcons were the only team to allow a conversion rate greater than 50% in 2006.

3rd down % defense has a negative relationship with a team's record in close games. As a team allows a higher conversion rate, their record in close games should decline. Once again this relationship is also weak with an r squared value of only .0963.

FG%

Clutch kickers should help a team pull out close games. Field goal % is simply the number of made field goal divided by the number of field goal attempts. The North Carolina Tar Heels made all ten of their field goal attempts in 2006. For teams with more than ten attempts, the Southern California Trojans made 16 of their 17 field goal attempts on the year (94.1%). The Kent State Golden Flashes had the worst accuracy, converting only two of their ten field goal attempts. For teams with more than ten attempts (barely), the Duke Blue Devils made four out of eleven (36.4%) to finish last.

Field goal % has a positive relationship with a team's record in close games. This means as field goal percentage improves, a team's record in close games should also improve. However, this relationship is nearly non-existent. The r squared value is a paltry .009. How can something that seems so vital to a team's success in close games have no relationship? One need only look at the 2006 Florida Gators to devine an answer. The immediate thought that comes to mind when discussing field goal % and close games is that a team with a good kicker will win those games more often because of their kicker. What if they win those games more often in spite of their kicker. In 2006, Christ Hetland attempted all of Florida's 15 field goals. He made six of them (40%). In 2006, Florida played five close games and had a 5-0 record (discounting the Auburn game that was a ten point margin thanks to the games final play). In their one-point win over Tennessee, Hetland missed both his field goal attempts. In their seven-point win over Georgia, he was again 0 for 2. In their one-point win over South Carolina, he did manage to make one of his two attempts. In their seven-point win over Florida State he missed both his attempts. Even if he had made both against Tennessee, that game would have come down to the wire, but leaving points on the board against Georgia and Florida State made those games much closer than they should have been. Another make against South Carolina and it wouldn't have take a block party from Jarvis Moss and Ray McDonald to squeak out a win. Despite his best efforts, Chris Hetland failed to sabotage the Gators national title dreams.

Scoring Offense

Scoring offense is simply the number of points scored divided by the number of games played. Hawaii led the nation in scoring in 2006, averaging 46.86 points per game. Once again Florida International brought up the rear averaging only 9.58 points per game.

Scoring offense has a positive relationship with a team's record in close games. As a team scores more points, their record in close games should improve. Once again, the relationship is weak. The r squared value for the correlation is only .0479.

Scoring Defense

Scoring defense is the number of points allowed divided by the number of games played. Virginia Tech allowed the fewest points per game in 2006 (11 per game). At the other end of the spectrum was Louisiana Tech. The Bulldogs allowed 41.7 points per game.

Scoring defense has a negative correlation with a team's record in close games. As a team allows more points, their record in close games should decline. Th relationship is still relatively weak with an r squared value of .1214.

None of the six team statistics examined here is highly adept at predicting a team's record in close games. This seems to be further proof that close games are nothing more than coin flips or crap shoots. However, something interesting does show up when you take a second look at the r squared values.

Scoring Defense: .1214
3rd Down % Defense: .0963
Turnover Margin: .0502
Scoring Offense: .0479
3rd Down % Offense: .025
FG %: .009

Both defensive statistics have a much stronger correlation (although still relatively weak) than any other statistic, especially the offensive statistics. This seems to reiterate a finding I posted about a year ago that good defensive teams tend to win more than their fair share of close games. Just some examples off the top of my head are Ohio State in 2002 and my beloved Demon Deacons in 2006.

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