Belichick goes for it on 4 and 1 from own 29: Is he crazy?

Bill Belichick has received a lot of negative attention for his decision to go for it on 4 and 1 from his own 29 yard line with 2:00 minutes remaining in the game and his team leading by 6 points.

I have found that it's far too easy to judge a decision based on the outcome. If Belichick goes for it on 4 and 1 and gets it, he is a genius and his risk taking is heralded as evidence of his greatness. If Belichcik goes for it on 4 and 1 and doesn't get it, everyone and their brother rails against Belichick for his recklessness and brash decision making.

I think it's more important to examine the thought behind the decision than simply look at the outcome of the decision. My favorite football blog, Smart Football, takes a closer look at Belichick's decision:

The goal is, obviously, to maximize your chance of winning. If you punt, your chances of winning are your odds of stopping a streaking Manning who has just torched your defense the whole fourth quarter. He will have to drive about 70 yards. Because of his excellence in clock management, the two-minute warning, and their timeout, time was not really a factor. (The analysis would be much different if there was only, say, a minute left.)

If you go for it, your chance of winning hinges on two outcomes: (a) if you get the first down, you win the game; and (b) if you don’t get it, you still have a chance to stop manning. So your chance of winning if you go for it is the sum of (a) your chance of converting; and (b) your chance of stopping Manning from the 30 yard line.

My best estimation is that the odds of converting on fourth and two (around 60% for the league, so probably closer to 65% for New England) plus stopping Manning from the thirty are greater than your odds of merely stopping Manning from seventy or so. Remember, the decision is also context specific: Manning was playing great and they had a gassed defense.

But feel free to disagree with me, though if you do I want to hear your reasons, not conclusory statements that it was stupid. I will say this: Agree or disagree, it was the ultimate compliment to Manning and showed similar faith in his own guy. I don’t have a problem with the call. As Herm Edwards says, you play to win the game, not to satisfy someone else’s preconceived notion about what makes a good football call.

A little more on this issue from Advanced NFL Stats:

New England coach Bill Belichick is taking a lot of heat for his decision to attempt a 4th down conversion late in the game against the Colts. Indianapolis came back to win in dramatic fashion. Was the decision a good one?

With 2:00 left and the Colts with only one timeout, a successful conversion wins the game for all practical purposes. A 4th and 2 conversion would be successful 60% of the time. Historically, in a situation with 2:00 left and needing a TD to either win or tie, teams get the TD 53% of the time from that field position. The total WP for the 4th down conversion attempt would therefore be:

(0.60 * 1) + (0.40 * (1-0.53)) = 0.79 WP

A punt from the 28 typically nets 38 yards, starting the Colts at their own 34. Teams historically get the TD 30% of the time in that situation. So the punt gives the Pats about a 0.70 WP.

Statistically, the better decision would be to go for it, and by a good amount. However, these numbers are baselines for the league as a whole. You'd have to expect the Colts had a better than a 30% chance of scoring from their 34, and an accordingly higher chance to score from the Pats' 28. But any adjustment in their likelihood of scoring from either field position increases the advantage of going for it. You can play with the numbers any way you like, but it's pretty hard to come up with a realistic combination of numbers that make punting the better option. At best, you could make it a wash.