Week 17, Raiders at Chiefs
4th-and-21, 3:23 remaining in 4th quarter, Up by 13
The Chiefs went for it on a 4th-and-21 on the Raiders’ 31. The NYT 4th Down Bot would have punted or attempted a field goal.
If you disagree

I lean slightly towards attempting a field goal, but I don’t have strong feelings here – my numbers tell me that either attempting a field goal or punting could be the best play. Specifically, punting would be the right call if you think the Chiefs’ chances of making a field goal are less than 39 percent. (Based on my analysis of over 13,000 field goal attempts since 2001, I give the average kicker a 62 percent chance to make a kick from this distance in a outdoor stadium.)

Here's the full breakdown of my calculations:

Option Chance of converting
Chance of winning
Before play
After play Change
Field goal try48 yard kick (est.) 62% 95% 96% +1%
Punt 95% 95% -
Go for it4th and 21, opp. 31 10% 95% 94% –1%
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. 31
Up by 13 with 3:23 remaining in the 4th quarter
Behind my field goal number
How important was this call?

If the coach had attempted a field goal instead of going for it, I estimate the Chiefs’ chances of winning would be about 96 percent instead of 94 percent.

What coaches usually do
Field goal try 64% of the time
Punt 32% of the time
Go for it 5% of the time
Based on about 1,135 fourth downs in similar situations since 2001.
What happened

Cairo Santos pass to the middle to Anthony Sherman for 3 yards to the Oak28. Cairo Santos pass to the middle to Anthony Sherman for 3 yards to the Oak28.

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!