Week 6, Dolphins at Titans
4th-and-21, 11:44 remaining in 3rd quarter, Down by 14
The Titans punted on a 4th-and-21 on the Dolphins’ 48. The NYT 4th Down Bot mentally high-fives that call.
If you disagree

The coach and I agree that punting is the thing to do here, but you may be thinking it makes sense to go for it. That would be the right call if you think the Titans’ chances of converting on fourth down are greater than 29 percent. But based on my analysis, I’d give the Titans only a 10 percent chance to get a first down here.

Here's the full breakdown of my calculations:

Option Chance of converting
Chance of winning
Before play
After play Change
Punt 6% 6% -
Go for it4th and 21, opp. 48 10% 6% 5% –1%
Field goal try65 yard kick (est.) <1% 6% 4% –2%
My decision in context

Along with some circuitry to come up with a win probability for every game situation, all you need to figure out what you should do next is an estimate of how likely you are to make a field goal or convert a first down.

My estimates for these are based on the results of thousands of similar plays, but you may think you're smarter than I am. This chart shows you how changing those estimates would change my recommendation.

What to do on 4th-and-21 on opp. 48
Down by 14 with 11:44 remaining in the 3rd quarter
What coaches usually do
Punt 90% of the time
Go for it 10% of the time
Field goal try -
Based on about 1,925 fourth downs in similar situations since 2001.
What happened

Brett Kern punts for 27 yards to Mia21.

Where did these numbers come from?

To estimate a team’s chances of winning, I use a mathematical model that accounts for a whole lot of variables — including the difference in score, the time remaining in the game, and the number of timeouts each team has left. On top of that, I have models for the likelihood that a team makes a field goal and the likelihood that it will convert a first down.

By combining all of this information, I can come up with the best decision a team can make, according to math.

If you want even more details about the numbers behind my decisions, my full model is available on GitHub. Help make me better!