Week 16, Packers at Cardinals
4th-and-2, 4:49 remaining in 2nd quarter, Down by 10
The Packers went for it on a 4th-and-2 on their 45. The NYT 4th Down bot thinks that’s a great idea, although punting 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 punting could be the best play. Specifically, punting would be the right call if you think the Packers’ chances of converting on fourth down are less than 50 percent. (Based on my analysis, I’d give the Packers a 56 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 2, own 45 56% 14% 14% -
Punt 14% 14% -
Field goal try72 yard kick (est.) <1% 14% 9% –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-2 on own 45
Down by 10 with 4:49 remaining in the 2nd quarter
What coaches usually do
Punt 62% of the time
Go for it 38% of the time
Field goal try -
Based on about 1,237 fourth downs in similar situations since 2001.
What happened

Tim Masthay rush to the left for 7 yards to the Ari48. Tim Masthay rush to the left for 7 yards to the Ari48.

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!