Week 17, Vikings at Packers
4th-and-4, 1:19 remaining in 3rd quarter, Down by 17
The Packers went for it on a 4th-and-4 on the Vikings’ 37. The NYT 4th Down bot would have done the same thing, although attempting a field goal would have been fine, too.
If you disagree

I lean slightly towards going for it, but I don’t have strong feelings here – my numbers tell me that either going for it or attempting a field goal could be the best play. Specifically, attempting a field goal would be the right call if you think the Packers’ chances of converting on fourth down are less than 24 percent. (Based on my analysis, I’d give the Packers a 48 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
Go for it4th and 4, opp. 37 48% 5% 6% +1%
Field goal try54 yard kick (est.) 36% 5% 5% -
Punt 5% 5% -
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-4 on opp. 37
Down by 17 with 1:19 remaining in the 3rd quarter
Behind my field goal number
What coaches usually do
Field goal try 50% of the time
Go for it 36% of the time
Punt 15% of the time
Based on about 889 fourth downs in similar situations since 2001.
What happened

Aaron Rodgers pass to the left to Randall Cobb for 4 yards to the Min33. Aaron Rodgers pass to the left to Randall Cobb for 4 yards to the Min33.

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!