Should NFL Teams Go For 2?

     For the entirety of its existence, the NFL's two-point conversion rule has been used in obvious late-game situations and little more.  In fact, three situations probably account for over 95% of two-point attempts.  Scenario 1: a team scores a touchdown late in the fourth quarter and is down two points.  They go for the tie.  Scenario 2: A team scores a touchdown to go up one or five with just a few minutes (if that) remaining.  They attempt the conversion to put them up either a field goal or a touchdown.  Scenario 3: A team is down in the fourth quarter by 11 or 16 points.  After putting up six, they go for two to reduce the deficit to either three or eight points- meaning they now only need a field goal to tie, or they make it a one-score game. However, with the NFL's new rules regarding extra points, should teams be rethinking their strategy of defaulting to a PAT?

     It's classic game theory, and I love that sort of thing.  The main idea here is simple: teams want to score points.  Naturally, this means they make the decision on whether to kick an extra point or go for two based upon what will bring them the greatest amount of points.  Since the actual kicking of extra points has been largely a formality with make rates above 99%, and the league's two-point success rate fluctuates between 45 and 50 percent, extra points have been mathematically more effective.  Additionally, the PAT is viewed as the much safer choice.  It's easy to criticize a coach for a missed two-point attempt.

     However, for years people complained about extra points being too easy, and this year the NFL finally made a change, increasing the PAT distance from 19 to 33 yards.  So with extra points now significantly harder, does the math actually lean in favor of going for two?

     Well, through the first six weeks of this season, 438 extra points have been attempted, and 417 have been made, for a 95.2% success rate.  While still very high, this mark is a large decrease from the nearly 99.5% of extra points made over the previous two seasons (2538/2551).  Extra points are now being missed at nearly ten times higher of a frequency.  Two-point conversions have been successful in 17 of 41 tries this year, a 43.9% rate.  Hold on.  This means that on average, a team going for two gets a return of just .878 points (.439x2). That's significantly below the extra point expected value (EV) of .952.

     The problem here is sample size.  We're looking at a small number of attempts, and so far it's been a poor year for the two.  Since 2010, 330 two-point tries have occurred, and 157 have been converted.  In every season the conversion percentage has been between 46 and 50 percent, with the overall average being 47.6%.  Now here's where it gets fun.  During this span, what has the EV of going for two been?  .952, the exact same as for the new 33-yard extra point.

     The decision to go for two has now become one of coaching philosophy.  One interesting thing to note is how many times teams have already gone for two this season.  During the 2010-2014 seasons, an average of 57.8 two-point attempts occurred league-wide per year.  This year, we're pacing for 115.3 attempts, almost exactly twice as many.  There are two reasons for this.

     First, teams are simply more willing to go for two at points where it isn't necessary.  If a team's offense has had an efficient drive, the positive momentum could increase their odds at the two.  It's risky, but if you string three together, you've bought yourself a free field goal.  It could also simply catch the defense off guard.  The Pittsburgh Steelers were doing this before Ben Roethlisberger's injury.

     The other reason is that teams are straying away from the concept that there are times "too early" to go for two.  For whatever reason, coaches have always seemed to think that going for two is too risky unless it occurs near the end of the game.  Down 21-19 in the third quarter?  Kick the extra point, it would be dumb to go for two.  I never really understood the logic behind this, so I'm happy it's a fading idea.  Let's think about it.  If you elect to go down one point, you need to score again to take the lead, and if you kick a field goal, the other team can just kick a field goal and retake the lead.  There is basically no difference in being down one or two, so I've always believed it's worth the risk to go for the tie.
     So since the PAT/2-pt decision is so mathematically close, what is my personal opinion?  Well maybe I'm old school, but I think generally the right call is to play it safe and kick the extra point.  I love the two when it would tie the game or bring a lead to an important number like three or seven, but more times than not (scoring a TD on the first drive of the game, for example), there really isn't much reason to go for two unless you think the opposing defense is so bad you are almost guaranteed success.  Again, it's easy to criticize a botched two-point conversion, and missing it and if you just so happen to lose by one point...well it won't be pretty.
     But hey, to each their own, and expect to see more teams going for two in the future.