By Kurt Bullard
Kurt is a sophomore at Harvard and a second-year member of the Harvard Sports Analysis Collective. He intends to major in either Economics or Statistics. Go 'Cuse.
Football fans – and sports fans in general – abhor the fact that mistakes made by the referees at the end of games can influence the result of the contest. Nowhere was this seemingly more apparent than in this week’s Monday Night Football game. Indianapolis seemed to have the game all but wrapped up towards the end of the fourth quarter. With a 27-20 lead and the ball at the Eagles 22 with 5:15 remaining, the Colts seemed poised to score – either by capping off the drive with a touchdown or settling for a field goal behind the reliable leg of Adam Vinatieri. However, on a 3rd and 9 call, Luck dropped back and targeted T.Y. Hilton, but was intercepted by Malcolm Jenkins, injecting the Eagles with what seemed to be a second life. The Eagles managed to score quickly to knot up the game behind the legs of Darren Sproles and would go on to win the game in regulation off the leg of Cody Parkey. However, this was all possible due to a missed pass interference call on Brandon Boykin, who held Hilton coming out of his break, allowing the ball to sail past Hilton and into the hands of Jenkins.
How big of a missed call was this? Assuming – based on the (-3) line on the Colts to begin the game – that the pre-game win probability for Indy was 62% (all win probabilities taken from Advanced Football Analytics' Win Probability Calculator), we could look at the win probabilities that could have happened in different possibilities off of that play. Before the Luck interception, there was a 92% probability that the Colts would have prevailed. After the interception, there was only a 87% chance that the Colts would go onto win. So, in retrospect, the interception was not that big of a swing immediately – a mere 5% points. The Colts would be predicted to pull out a victory in 7 out of 8 of these situations.
However, if we examine other possible outcomes of this play, we can take a look at how much of an impact this down could have had if it were called differently or went differently. If pass interference had been called on Boykin – which mostly everyone believes should have been done – then the win probability for the Colts would have risen by 3% to 95%. A first down here would have been nice, but it would have been no means been a clincher – the Eagles could have either forced a turnover later in the drive or held Indy to a field goal and still had time remaining. However, few people would have ventured to bet on that actually happening given a first down in that situation.
In another scenario, if Boykin doesn’t commit pass interference, the result of the play could have been either a first down or an incompletion. A first down by completion would have had the same effect on win probability as if it had been acquired by pass interference. However, an incompletion would have led to a 39 yard field goal attempt by Adam Vinatieri, from which there are two possibilities – he makes, or he misses. If he misses the field goal – and the play took a standard five seconds to complete – the Eagles would have had a remaining win probability of 15%. If Vinatieri had made the clutch field goal – as he seemingly usually does – that win probability would have been reduced to 10%.
Incompletion, Field Goal
Incompletion, Missed FG
In fact, Darren Sproles’ 51 yard catch to bring the Eagles within 6 yards of tying the game – a play on which there were no apparent missed calls – had a far greater impact on the game. Faced with 2nd and 10 at their own 43, the Eagles only had a 16% chance of emerging victorious. But after Sproles’ huge reception, that probability went up to 35% - a twenty point swing on a play that the Colts did indeed have control over.
So, even though the call was questionable at best, the Colts still have to look inward after that loss. It’s tough to blame surrendering a quick touchdown, going 3 and out, and giving up a late drive and game-winning field goal in successive drives on the referees.