By Henry Johnson
December 6 was shaping up to be a perfect end to the regular season for the Oklahoma Sooners football team. OU was coming off of consecutive wins, the rival Oklahoma State Cowboys were in town for the Bedlam game, and it was senior day in Norman. Underclassmen spoke of wanting to send their elders off with a victory. Coach Bob Stoops waxed poetic about time spent with the soon-to-be graduates. Seniors were honored on-field before the game, and fullback Aaron Ripkowski received the Don Key Award, given annually to a departing star.
The spirit of senior day would seem to ignite players’ will to win, and some pre-game analysis agrees with this assertion. While the logic of this argument—that seniors have an added incentive to win on their namesake day—seems sound, it’s worth testing whether it holds up in practice. To do this, I’ve downloaded the last 10 years of betting spread data from Warren Repole’s Sunshine Forecast collection. The hope is that the Las Vegas lines will have accounted for team abilities and home field advantage, so that it’s possible to test the effect of senior day with fewer confounding variables. For the sake of this analysis, “senior day” will be defined as a team’s final home game of the season.
The chart shows that there isn’t a huge difference in whether or not a home team will cover based on the fact that the game occurs on senior day. In fact, teams playing their final home game of the year have covered slightly less often over the last ten seasons. To test whether this inability to beat the spread is significant, we can run a linear regression where covering the spread is the dependent dummy variable and senior day is the independent dummy variable.
It appears that the senior day slump is not a statistically significant phenomenon. As Will Ezekowitz has noted when using the betting line methodology, this doesn’t mean that senior day isn’t helpful or harmful for teams. It simply means that this information may already be factored into the spread. And while this isn’t the most electrifying finding, it at least allows us to take with a grain of salt the betting advice of those who stress the importance of senior day. For Oklahoma Sooners fans, this is a lesson hard-learned.