The NFL changed the rules for the point after touchdown this year moving an extra point try from the 2 yard line back to the 15 yard line. Before the season I was convinced this would cause teams to go for 2 more often. To my surprise, teams kept kicking extra points most of the time.
Teams did start going for 2 more often, but not nearly as much as I thought they would. In 2015 NFL teams went for 2 94 times, a big increase of 59% over the 59 times they went for 2 in 2014. Even with the big increase teams still only went for 2 about 7% of the time they scored a touchdown. There were 1.289 touchdowns scored this year. Teams went for the 2 94 times and attempted the extra point 1,198 times.
But should teams still be kicking extra points? Many statisticians say that football coaches are too conservative and would do better if they took more risks. Let’s look at whether going for 2 more would lead to more wins.
Do you score more points if you go for 2?
To figure out if NFL teams should go for 2 instead of kicking extra points we will look at the expected value of each option. The expected value is on average how many points you would expect each option to be worth. The expected value is calculated simply by taking the number of points that could potential be scored by the percentage chance of that score being successful.
Kicking the extra point is worth 1 point. During the 2015 regular season 1,127 out of 1,195 extra point attempts were successful, so we will say the percentage chance of an extra point being successful is 94%. 1 point X 94% tells us that when a team kicks the extra point on average the expected value will be 0.94 points. You can’t score fractions of a point in football of course, but the .94 represents the average over a season.
NFL teams went for 2 94 times in 2015 and were successful 45 times which works out to a success rate of about 48%. 2 points multiplied by the success rate of 48% means that going for 2 will earn teams an average of .96 points.
Not much difference
So the kick is worth .94 points and the 2 point try is worth .96 points. Virtually no difference.
If a coach went for 2 every time it would be lead to endless discussion by football experts and strong options on both sides, but wouldn’t really make a difference. On average NFL teams scored 40 touchdowns during the 2015 season. If they kicked the extra point all 40 times they would expect to score 38 points in extra points in a season. If they were radical and went for 2 each time they would expect to score 39 points after touchdowns, just 1 additional point over the course of a season.