The New York times runs a twitter account for a “Fourth Down Bot” (@NYT4thDownBot) that analyzes every 4th down call in NFL football games. The bot gives advice and sometimes a short report summarizing the probability of success associated with each of the choices:
The bot has a lot of personality!
Brian Burke provides the methodology, which is here. The recommendations are based on which actions (going for it, punting, or going for a field goal) yields the most expected points. In the last 10 minutes of a game, the bot selects recommendations based on which yields the highest win probability. These concepts are not equivalent – going for it may maximize your points, but if time is running out and you are down by two, it might be better to go for a field goal than try for a touchdown.
The bot is useful because there is such a huge difference what is the best strategy and what coaches actually do. The picture below illustrates the difference. There are a number of explanations for the difference. One is that fans and owners only remember the times it doesn’t work–following the optimal policy may maximize the number of wins on average, but losing a game could mean losing your job. When the objective is to keep your job and not win games, everyone gets used to more conservative and suboptimal play calling.
Sports nerds have known about this issue for a long time. I’ve even blogged about it before (here and here).
The Fourth Down Bot is so high profile that it has really raised awareness of this issue, possibly to the point that it may change how the game is played. If the fans know that it is better to go for it on fourth down and if the coaches and owners read the scathing fourth down reports questioning their decision-making, then maybe it will be unacceptable for coaches to cling to sub-optimal policies. Maybe I’m too optimistic about the Fourth Down Bot’s chance at improving scientific literacy to the point when the game changes. It’s possible that coaches and owners will be dismissive of math models and the nerds who make them, but I hope the Fourth Down Bot chips away at our society’s distrust of math.
It’s worth noting that the Fourth Down Bot is genderless and does not have a race. Until I blogged about the bot, all of the sports nerds and number crunchers I’ve read and blogged about are men. I can’t be the only women interested in these issues. Please introduce me to other women and minority sports nerds – I am more than willing to promote sports number crunchers from underrepresented groups.
Has the Fourth Down Bot changed the way you think about football? Do you think the Fourth Down Bot has the potential to change the game?
January 6th, 2014 at 8:53 am
That graphic is great, but I think it would be better as a scatter with green, orange and purple points, so I could see which combinations of yards-to-go and field position most frequently occurred; what’s interesting isn’t whether the bot and the coaches disagree over a large portion of phase space, what’s interesting is whether they disagree over a large proportion of actually occurring game situations…
January 6th, 2014 at 4:21 pm
This reminds me of The Coach Who Never Punts – http://www.grantland.com/story/_/id/9970245/grantland-channel-coach-never-punts.
He also always uses the onside kick.
The bias for remembering the failed attempts is unfortunately getting in the way of the math.