The Fifth Down blog features an article about a new phone app, one that says it will give you the winning chances of every play during the game. In the article, we get this little gem:
According to his analysis, a team that returns a kickoff to its 40-yard line can be expected to score an average of 3 more points on the drive than if it had started at the 20-yard line.
“If you make it to the 40, you essentially just made a field goal, even if you don’t realize that immediately,” Bessire said.
I seriously doubt this. 3 points * 100 yards / 20 yards = 15 points. I don’t know of anyone who scales an expected points curve to be worth 15 points. I don’t know of a single reliable EP solution with slopes routinely greater than 0.08 points per yard in between the 20 yard lines.
You pay your money, and you take your chances. Simply put, I can’t recommend this app.
September 12, 2012 at 8:59 am
Looks like it’s worth slightly more than one point. http://www.advancednflstats.com/2008/08/expected-points.html
September 12, 2012 at 8:59 am
That’s really bizarre. Our expected points model says 1st-and-10 at the 20 is worth about 0.3 EP, and 1st-and-10 at the 40 is worth 1.6 EP (a difference of 1.3). Now, that’s in net points, but Keith Goldner’s Markov rest-of-drive model says the offense’s exp pts go from about 1.4 to 2.1, a difference of 0.7 (I attribute the difference between that and our EP to a simultaneous decrease in the defense’s expected pts when they get the ball back). At any rate, that’s nowhere near 3 points. I have no clue how he came up with that.
September 12, 2012 at 9:06 am
If I were to hazard a guess, someone multiplied by 2 by accident. This is assuming an off the cuff review. However, if the statement is accurate of the app, they have a problem.
October 8, 2012 at 9:24 pm
could it be that making it to the 40 proxies some unobserved determinants of getting a field goal for which you have failed to account in your calculation of expected points? 1st and ten at the 40 is not the same as 1st and ten at the 40 given a you just returned a kickoff to the 40.
October 8, 2012 at 9:25 pm
sorry not fieldgoal, scoring
October 9, 2012 at 7:23 am
In short, no. All that gets factored into the play-by-play data. The most likely cause of an error like this someone getting the opponent’s 40 and his own 40 mixed up. The 40 yard difference from your own 20 and the opponent’s 40 yard line is worth about 3 points.
D-