Using the Spread and Over/Under to Predict Super Bowl Scores

Every year, millions of dollars are poured into betting on the Super Bowl. The two most prominent things you can bet on are the points spread and the over/under. By combining where these two things end up, one can approximate what score might have been expected based on these lines.

For instance, in Super Bowl II, the Packers were favored to beat the Raiders by 13.5 points with an over/under of 43. The “expected” score for this game based on these factors was Packers 28.25, Raiders 14.75: the Packers win by 13.5 points and the teams combine for 43. By winning 33-14, the Packers exceeded the expectation by 4.75 points while the Raiders fell 0.75 points short (though we all know fractional scores are impossible).

By clicking this link (I don’t know how to add tables to WordPress, maybe someone can help me on that) you can see these calculations for every Super Bowl from II to XLIX. (I cannot find an over/under for Super Bowl I.) The table is sorted by how much each team exceeded their “expected” score (e.g., for the Packers in SB II the figure is 4.75). That specific “statistic” will be the basis for the rest of this post. The scare quotes around expected are going to be dropped too. It’s just easier that way.

The average team exceeded their expected points total by 1.08 points per game. That seems to suggest the Vegas lines, while they may slightly overstate scoring, are overall okay at prognosticating the score.

The 2002 Buccaneers were expected to lose to the Raiders by a score of about 24-20, but won 48-21. The 27.75 points they beat their expectation by are the most ever.

Unsurprisingly, the 1968 Colts posted the worst score. They were supposed to win 29-11 and lost 16-7, falling 22 points short of expectation.

The second worst game looking at things this way was 18-0 New England’s performance against the Giants in 2007. While 21 out of 98 teams have scored 14 or fewer points in a Super Bowl, New England was expected to put up 33.5 points–fewer than they had scored beating the Giants 38-35 to conclude their 16-0 regular season, but 19.5 more than they did manage.

Even though the 2013 Broncos outscored the 2007 Patriots 606-589, and mustered just 8 points in Super Bowl XLVIII, they fell “only” 17 points short of the expectation. The 25.0-22.5 score the line indicated certainly had something to do with the quality of the 2013 Seahawks defense.

But on to happier things. The list of teams to exceed their expectation by the most is not surprising at all: rounding out the top 5 after the 2002 Bucs were the 1992 Cowboys (won 52-17), 1989 49ers (won 55-10), 1985 Bears (won 46-10), and 2013 Seahawks (won 43-8).

None of those teams had the highest expected score. That belongs to the 1994 49ers, who were supposed to score 35.5 points against the Chargers. They got 49.

Meanwhile, the 1968 Jets were the most maligned by the oddsmakers, expected to score 11 points, which they of course outdid by five.

I’m loathe to use these numbers to judge quarterbacks, mostly because of defensive and special teams touchdowns producing a lot of noise. But if you’re looking for ammo against Peyton Manning, his teams have under-performed by 9.4 points, the worst among QB’s with three or more starts in the Super Bowl.

With the current lines for Super Bowl 50 at Panthers by 5.5 and an over/under of 45, the Broncos are expected to put up roughly 20 points. (The exact projected score is Carolina 25.25, Denver 19.75, so you might expect a score like 24-20 or 27-20.) They would have to score 49 for Manning’s teams break even.

If you’re a Patriots fan, don’t get too cocky about this. New England’s 2007 performance is the worst of Manning and Brady’s nine Super Bowls to date. New England’s -3.2 points per game with Brady is worse than even the expectations put on Jim Kelly’s Bills, who scored only 2.4 points fewer per game from 1990-93 than the Vegas lines would have indicated.

Quarterbacks whose teams over-performed include Joe Montana’s 49ers, of course, at +7.4 and, somewhat surprisingly, Roger Staubach’s Cowboys at +6.3 points per game. (Super Bowl XIII with Bradshaw and Staubach was, in fact, the most that teams have ever exceeded the over/under: the 35-31 final score was 27 points higher than the meager over/under of 39. Dallas was only supposed to score 14.25 points in the game.)

Enough from me though. Anything strike you about the list?