Wednesday, January 28, 2015

Why you often shouldn't go for it on 4th down


It doesn’t matter the distance; kicking has been on a steady upward climb. If we look back even further, we can see indicators that kicking has been on a similar trajectory for the entire history of the league. ...

If you’re reading this site, there’s a good chance you scream at your television a lot when coaches sheepishly kick or punt instead of going for it on fourth down. This is particularly true in the “dead zone” between roughly the 25- and 40-yard lines, where punts accomplish little and field goals are supposedly too long to be good gambles. ...

As of 10 years ago — around when these should-we-go-for-it models rose to prominence — we were still right. But a lot has changed in 10 years. Field-goal kicking is now good enough that many previous calculations are outdated. ...

There’s no one universally agreed-upon system for when you should go for it on fourth down. But a very popular one is The New York Times’ 4th Down Bot...

Comparing those to my model, it looks to me like the bot’s kickers are approximately 2004-quality. (I asked Burke about this, and he agrees that the bot is probably at least a few years behind, and says that its kicking assumptions are based on a fitted model of the most recent eight years of kicking data.) ...

The following table compares “Go or No” charts from the 4th Down Bot as it stands right now, versus how it would look with projected 2015 kickers:
Having better kickers makes a big difference, as you can see from the blue sea on the left versus the red sea on the right. ...

While the updated version still concluded that coaches were too conservative (particularly on fourth-and-short), it found that coaches were (very slightly) making more correct decisions than the 4th Down Bot.
--Benjamin Morris, FiveThirtyEight, on updating our football analytic intuitions