Testing Matchup Myth #1: the Rematch

Myth #1: It's hard to beat the same team twice in one season
Myth #2: You can throw out the records for a rivalry game

In this first edition of the two part series, I will be taking on myth #1.

Billy Sims and the Sooners would
get revenge and redemption

The principal idea seems to be that the winner of the first game has less to prove in round 2, is overconfident entering the game, and therefore does not prepare as well or play as hard. The game 1 loser is looking for revenge or redemption.

In modern-era college football, teams play a second time in a bowl game or conference championship game. This is important for two reasons: first, it means that the teams are relatively evenly matched; second, it means that there is a whole new set of motivational variables (e.g. if the team is happy or disappointed to be in that particular bowl game) that will dilute the importance of seeking revenge or redemption for the loser.

There is a second countervailing logic: the winner of the first game already divined a game plan that wins. The loser will need to reevaluate its game plan, and faces a degree of uncertainty that the game plan will be effective. In other words, if the two teams are otherwise evenly matched, the team that won the first game has a better chance of winning the second game precisely because it won the first game.

The Choke at Doak: 31-3 to 31-31; The 5th quarter
in the French Quarter was no better for Florida

So, let's look at the numbers. Since 1950, there have been 49 rematches in college football. (Florida State tied in game 1 in 1994 - the infamous Choke at Doak.) The average score in game 1 has been 29.5-16.4, and in game 2, 31.0-17.7. Home teams were 31-16-1 in game 1. Most game 2s were played on neutral fields; home teams were only 4-6.

Game 1 winners were 29-18 in second games (62%). Simplistically, 62% is less than 100%, so game 1 losers did better in game 2, but 62% is also more than 50%, so game 1 winners were still more likely to win game 2.

Thinking about this logically, the team that won the first game was probably the better team, and so we would expect them to win the second game more often than not. Based on their performance throughout the season, we would have expected game 1 winners to win 61% of game 2s. In reality, they won 62%. In other words, game 1 winners improved their chances of winning the rematch by 1 percentage point.

BYU/UCLA 2007

On average, game 1 winners won the rematch 26.4 to 22.5. We would have expected game 1 winners to win 26.6 to 22.0 on average. That means game 1 losers outplayed game 2 expectations by .79 points. Based on game 2 scores and a pythagorean-style win/loss adjustment, game 1 losers should have won 45% of game 2s, but they only won 38%. Game 2 losers played slightly better by the scoreboard, but they were unlucky when it came to actually winning games.

In conclusion, it is not hard to beat a team twice in the same season - winning or losing game 1 has no effect on winning or losing game 2. But it is hard to blow a team out twice in the same season. So Nebraska/Washington Part II might be closer than 55-21, but don't expect Washington to pull off the upset just because they lost the first time around.