Week 3, Browns at Dolphins
4th-and-8, 7:36 remaining in 1st quarter, Down by 7
The Browns attempted a field goal on a 4th-and-8 on the Dolphins’ 23. The NYT 4th Down bot is totally on board, although going for it 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 Browns’ chances of converting on fourth down are less than 29 percent. (Based on my analysis, I’d give the Browns a 30 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 8, opp. 23 30% 12% 12% -
Field goal try40 yard kick (est.) 83% 12% 12% -
Punt 12% 10% –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-8 on opp. 23
Down by 7 with 7:36 remaining in the 1st quarter
Behind my field goal number
What coaches usually do
Field goal try 59% of the time
Punt 21% of the time
Go for it 19% of the time
Based on about 1,431 fourth downs in similar situations since 2001.
What happened

41 yard field goal attempt by Cody Parkey is NO GOOD. 41 yard field goal attempt by Cody Parkey is NO GOOD.

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!