By Kurt Bullard
The two-minute drill is one of the most exciting sequences in the NFL. Success in crunch-time can launch Hall of Fame careers, while failure to convert can aid in your becoming one of the most maligned figures in all of sports. Whether it’s fair or not, quarterbacks are heavily judged by their ability to lead offenses with little time on the clock. Every second, therefore, is crucial to a quarterback’s reputation.
It makes sense, then, that teams sometimes spike the ball to stop the clock. This may be one of the least exciting plays in the game, even if its fakes are some of the most exciting. But at its core, it’s a trade: a down for some extra time on the clock and less chaos when lining up at the line of scrimmage. With less time on the clock, the marginal utility of an additional down dwindles, so having two or three downs as opposed to three or four, respectively, is not that big of a deal.
However, there’s an alternative argument: the defensive chaos may outweigh the offensive chaos, and, by extension, an offense’s next play might be more effective in the no-huddle than it would be if both teams got recollect.
To look at this problem, I used NFL Savant play-by-play data from last season and this season though the end of November. To avoid meaningless drives at the end of blowout games, I only looked at the last two minutes of the second quarter. I then filtered through the data to find instances where teams may be inclined to stop the clock, looking at plays on 1st or 2nd down between 2:00 and 0:10 (to filter out spikes to set up field goals) where teams opted not to huddle. In total, I found 421 times where teams decided to no huddle, and only 29 times where teams forfeited a down and spiked the ball.
There are two main questions when it comes to spiking: how much time are you saving by spiking, and is it more effective to reset or keep the defense on its heels?
The first question is simple enough. It’s simply looking at the average length of a play leading up to a spike versus leading up to a no-huddle play.
|Time From Previous Snap to Spike||Time From Previous Snap to No-Huddle Play|
|15.7 seconds||19.3 seconds|
It turns out that this is indeed a statistically significant difference. So, essentially, a team is saving about four seconds of game time and a down by spiking the ball. Is that worth losing a down?
To look at this particular part of the problem, I ran a relatively simple regression. For spikes, I looked at the yards gained on the subsequent play, while, as is common sense, I looked at yards gained on the actual play for no-huddle plays. For my predictors, I looked at the yard-line on which the play took place, how many seconds were left in the half (as a gauge for aggressiveness), and whether or not there was a spike beforehand, and all three possible interactions. I then performed stepwise regression, which yielded the following model:
As you can see, the remaining variables are the yard-line and whether or not the play came after a spike. While the two variables don’t explain a lot of the variance in yardage, the two variables are still significant. And, interestingly enough, the spike term is negative, which is to say that a team, on average, gains more field position-adjusted yards in the no-huddle than it does after a spike. The shortfall of this analysis is that there haven’t been a lot of spikes to stop the clock that don’t come before setting up field goals. So, the magnitude of the coefficients is not very informative. However, it is nonetheless noteworthy that, even with a small sample, teams tend to do better when they catch the defense retreating rather than when the offense takes it time and is able to line up more precisely. Saving three seconds, then, may not be worth it when you both have more effective plays and don’t lose a down.
While Gronk should keep on spiking, maybe teams shouldn’t let the defense off the hook and stop the clock that often.