One of my favorite topics on which to write is football theory–why teams make the decisions they do and if they could become more efficient in their choices. In the past, I’ve completed studies detailing why teams should go for it more often on fourth down, run more on third down, throw more deep passes, run more frequently to the weak side, pass out of ‘running’ formations, be far more aggressive on 2nd and short, and so on.
It is my view that, if a coach was to implement a perfect understanding of advanced statistics and game theory into his in-game decisions, the potential impact would far outweigh that of any single player. A “perfect” record of fourth down decisions, for example, could be “worth” a handful of points to a team in any individual game. With all of the statistically inefficient choices NFL head coaches make each and every game, there is an enormous opportunity for less talented teams to outperform superior ones based solely on statistics. Now is truly a golden age for the NFL in that teams are just beginning to crack the surface of advanced statistics that baseball uncovered years ago.
One such statistical issue about which I feel very strongly is the use of two-point conversions. I talked about this issue at length during the 2010 season, particularly after the Cowboys’ Week Seven loss to the Giants and their Week 16 loss to the Cardinals. From the New York post-game review:
Later, the Cowboys did score a touchdown to close within 12 points. They decided to go for a two-point conversion, and Tirico immediately went off about “awful” the decision was. I normally like Tirico, but he needs to stick to play-by-play and keep his nose out of matters of football theory. On this topic, he was again as wrong as could be.
You’ll often hear announcers say it’s “too early to go for two.” But what does that even mean? How is it ever “too early?” The decision to go for a two-point conversion should be based on a variety of factors, including the score, a coach’s confidence in his two-point play, and so on. Actually, if the probability of Team X converting on a two-point attempt is 50.1 percent, they should almost always go for two. The expected points of 1.002 is greater than that of an extra point (which can obviously only be as high as 1, even with 100 percent accuracy).
Thus, you’d only want to go for an extra point in non-normal game situations. Suppose Team X scores a late touchdown to tie the game. They’d clearly want to attempt the extra point to secure the win. Going for two points would be quite disadvantageous in that scenario. If football commentators knew the statistics and theory behind two-point attempts, perhaps they’d be saying “It’s too early to try the extra point.”
There are more reasons that Tirico was unjustified in his stance. Down 12, the decision of whether or not to attempt a two-point try is indeed a “no-brainer,” but Tirico is on the wrong side of the debate. If you go for two points and succeed, you’re down 10 points and now know that a touchdown and field goal will tie the game. If you go for two and fail, you now know that you need two touchdowns to win. If you kick the extra point, however, you might later kick a field goal that will turn out to be meaningless.
The idea that you want to “keep yourself in the game” by kicking an extra point is preposterous. You actually want to determine what scores you’ll need as early as possible. If you kick the extra point, then a field goal, you’re down eight points. If you then score a touchdown and fail on the two-point attempt, you’re still another score away from winning the game. The field goal attempt in between touchdowns becomes all but meaningless, and this is due solely to the fact that you didn’t attempt the two-point conversion as early as possible. Failing the two-point try earlier, as I said above, provides you with the knowledge that you need two touchdowns to win.
Tirico and Jaws used the outcome of the game as justification for their view, but that’s wrong as well. If you roll a six-sided die and bet even money on a specific number coming up, your bet is a dumb one regardless of the outcome of the roll. The fact that you will win money one time out of six doesn’t justify the decision ex post facto. When I listen to the Monday Night Football crew, I feel like I am betting that an even number will come up on my roll of the die–but all the commentators, I mean numbers, are odd.
Later in the season, I criticzed Jason Garrett for his failure to attempt a two-point conversion in the third quarter of a game:
- Down 21-19 in the third quarter, Garrett decided to kick an extra point. Huge mistake. I’ve talked all season about why teams should try way, way more two-point conversions. Over the course of any given season, kickers make around 98 percent of extra points, while two-point conversions are successful around 48-49 percent of the time. While the expected points of extra points is higher (.98 x 1 is greater than .48 x 2), the difference isn’t great enough that it should overcome all game situations. For example, Garrett never would have kicked the extra point in the fourth quarter, as he doesn’t know if the Cowboys will score again.
- Further, two-point conversions are only statistically inferior to extra points because coaches tend to call the wrong plays down by the goal line. Over the last 20 seasons, rushing the ball has yielded a successful two-point conversion over 60 percent of the time. Even if a team went for two points after nearly every score and rushed the ball each time, I doubt the success rate would jump below 50 percent (the break-even level at which two-point tries are statistically equivalent to extra points, assuming a 100 percent success rate on the latter). Thus, extra points should actually only be attempted in very specific situations, such as a tied game in the fourth quarter.
- On top of all of that, let’s not forget Buehler is about as erratic as kickers come. His extra point success rate is nowhere near 98 percent (probably closer to 94 or so), meaning the Cowboys would only need to convert on 47 percent of two-point tries to yield the same expected points. And if you’re correctly running the ball, what does it matter if Stephen McGee is at quarterback?
- I assume Garrett attempted the extra point because he figured Dallas would score again anyway. That’s faulty logic, however. Even if we assume two-point conversions yield less expected points than extra points, and we take into account McGee’s presence in the lineup, the difference between a two-point try and extra point is still small enough that, for an extra point to be the right call, we’d have to assume there’s less than a one percent chance the Cowboys wouldn’t score again. While it’s likely the offense was going to put more points on the board, it certainly wasn’t greater than 99 percent.
- I updated live from the game last night on Twitter, and a few followers claimed that it was “too early to go for two and the chart says the extra point is the right call.” While I appreciate everyone who took the time on Christmas to read my thoughts, that reasoning is simply incorrect. What does it even mean to be “too early to go for two”? While you certainly have less of an idea of the final score in the first quarter as compared to late in the game, you should always side with statistics. If the numbers say attempting a two-point conversion is the right call (which they did for the Cowboys in the third quarter–and it wasn’t even close), then kicking an extra point is the risky move. Further, NFL coaches are just tapping the surface of advanced statistics and game theory, meaning most of their “infallible” charts are dead wrong. It’s Garrett’s job to give the team the highest probability of victory, and whether a decision seems “risky” or not to the public, it needs to be made.
Later, Garrett issued a statement on his decision to kick the extra point (below). I responded with this:
According to Jason Garrett, he didn’t go for two points when down 21-19 in the third quarter of Saturday night’s game because “What happens when you start making those decisions is sometimes you get a little hasty and say, ‘OK, if we get two here that will tie us up.’ But typically, what happens when you have another quarter to play, there are a couple more scores and the whole thing kind of plays itself out a little bit.”
Although I’d wager that the majority of NFL coaches agree with Garrett’s assessment, it is the wrong one. I hate to be so blunt about it (secretly I love it), but he’s just dead wrong. Garrett points out that there will typically be more points scored after the third quarter, which is correct, but somewhat irrelevant.
First of all, as I’ve already pointed out, two-point conversions may not even yield less expected points than extra points. If that’s the case (which would be a virtual certainty if teams ran the ball more on two-point attempts), then going for two points should be the status quo, with an extra point only being attempted in specific game situations (such as tied late in the contest).
Even if extra points are generally statistically superior to two-point tries, however, Garrett still made the wrong decision. While I agree with his notion that more points were likely to be scored, that fact is far from certain. Actually, for an extra point to be the right decision in that scenario, we would have to assume that the chances of neither team scoring again was small enough that it wouldn’t account for the disparity between the expected points of an extra point (about .98) and a two-point attempt (.96 at worst).
As it turns out, Garrett would have to assume either that the chances of neither team scoring again were below one percent or that the offense’s chances of converting on their two-point try were closer to 25 percent than 50 percent. Anyone believe either scenario to be the case?
I used a lot of old material here because I feel like actual game situations are the most effective way to state my case. We can see real-world situations in which forgoing a two-point try has dire consequences for a club.
Ultimately, I believe an NFL team could secure a significant number of “extra” points by attempting two-point conversions after the majority of touchdowns. As I stated above, NFL teams convert two-point attempts about 60 percent of the time when they run the football. That number would certainly decline with increased rushing attempts, but the efficiency of two-point pass attempts would subsequently increase. I see no reason why an NFL team (particularly one with an offense as potent as that of Dallas) wouldn’t be able to convert a minimum of 55 percent of two-point tries if they focused on improving their efforts.
Assuming the Cowboys score three touchdowns per game in 2011 (they scored 43 in 2009 and 46 last season), the “increase” in expected points would be 6.24 (assuming 97 percent accuracy on extra points, which is a stretch if David Buehler is still the kicker). That might not sound like a lot, but there’s a solid chance those “extra” points would result in another win for the ‘Boys. Assume a 60 percent conversion rate and that number jumps to 11.04. Not too shabby for a philosophical decision that would require relatively little practice time.