The Touts Favor the Colts; the Statistics Favor the Bears
By MICHAEL DAVID SMITH
NY TIMES
If it is true that offense wins games but defense wins championships, Bears Coach Lovie Smith will hoist the Vince Lombardi Trophy tonight.
This season, Smith’s Bears ranked fifth in total defense in the N.F.L., while the Indianapolis Colts ranked 21st. On offense, Chicago ranked 15th and Indianapolis third.
That adage about defense winning championships is supported by the results of past Super Bowls. In 20 of the 40 games, one team had a better defense during the regular season and the other team had a better offense, as judged by how many yards the teams gained and allowed during the regular season. The teams with the better defense won 15 of those 20 Super Bowls.
But Scott Berry, a former statistics professor at Texas A&M who uses statistical models to analyze football games, says there have been so few Super Bowls that it is shortsighted to draw any conclusions. Most of the time, he found, when two good teams play each other, offense wins out.
For an article called “Does Defense Win Championships?” in the academic journal Chance, Berry analyzed 3,316 N.F.L. games from 1993 through 2005.
“When one team has a good offense and the other team has a good defense, the offensive team has a slight advantage most of the time,” Berry said. The same held true in games between average teams.
But a curious thing happened at the top of the league. Berry’s article identified the 10 best offensive and defensive teams in the 13 seasons he examined. Of the teams ranked among the top offenses, only two won the Super Bowl, while another two missed the playoffs. Of the top 10 defenses, four won the Super Bowl, and all 10 made the playoffs.
Although Berry cautioned against drawing conclusions from such a small number of games, N.F.L. history is full of examples of great offenses that have come to a screeching halt when facing great defenses in the Super Bowl.
Four of the last six Super Bowls have paired a team with a superior offense against a team with a superior defense, and in all four, the defenses won: the Pittsburgh Steelers over the Seattle Seahawks last year; the New England Patriots over the Carolina Panthers in 2004; the Tampa Bay Buccaneers over the Oakland Raiders in 2003; and the Baltimore Ravens over the Giants in 2001.
Is this a fluke? Ask Marv Levy and his high-powered Buffalo Bills, who appeared in four consecutive Super Bowls in the 1990s only to lose all four to opponents with better defenses.
Even many Super Bowl champions that fans remember as great offensive teams actually serve as evidence for the importance of defense. San Francisco 49ers Coach Bill Walsh won three Super Bowls with his famous West Coast offense, but in all three of those title games, the 49ers actually ranked worse on offense and better on defense than the opponents they beat in the Super Bowl.
What does this mean for Super Bowl XLI? Berry believes the oddsmakers who installed the Colts as touchdown favorites are putting too much stock in Indianapolis. Berry says that his statistical model and the other mathematical ranking systems he knows of rated the Bears as either equal to or slightly better than the Colts.
“The betting line has Indianapolis by 7,” Berry said. “If you look at any rating system, this game is a statistical tossup.”
Berry said the greatest lesson any statistician could give is that the winner of the Super Bowl should not be anointed as a team of destiny. In reality, Berry said, the teams in this year’s Super Bowl and in most Super Bowls are close to evenly matched. Winning one game does not necessarily make the winning team superior.
“The commentators will speak about the game as though the winner would have won every time,” Berry said. “But the truth is that they would each win about 50 times if they played 100 Super Bowls.”