In 2015, to make extra point plays after touchdowns more uncertain, the NFL moved the extra point distance from the 2-yard line to the 15-yard line. Since the rule change, the expected points from an extra point attempt has fallen from 0.99 (averaging between the 2002 and 2014 NFL seasons) to 0.94 (averaging the 2015 and 2016 NFL seasons) while the expected points from the two point conversion remains 0.95 (averaging between 2002 and 2016 NFL seasons). While the total number of two point conversion attempts per season has almost doubled, most coaches still rarely attempt 2 point conversions when it would be point maximizing (and win maximizing under risk neutral or risk seeking preferences). Using dynamic programming, this paper argues that this result is evidence of a conservative bias and that teams could improve expected wins by attempting more two point conversions.
Hartley is at the Wharton School, here is the link (pdf).