- Atlanta's 4th Down Decision Vs. Tampa
By Brian Burke
4th and goals from the 15 might seem impossible, but they're not. The success rate is low but not zero. In fact it's about 14%. That's not a welcome prospect, but neither is handing the ball to an opponent who's up by 3 points with 4 minutes to play. And even if the conversion attempt fails, it's far from fatal. The calculus merely changes from needing a FG to tie, to needing a TD to win. Notice I said needing a FG to tie. Sure, TDs are harder to come by than FGs, but tying is not the object of the game. Put simply, TDs are more than half as likely as FGs in that situation, which makes the gamble for a tying FG a sucker's bet.
FG attempts are successful 88% of the time from the 15. A successful FG gives the Bucs the ball near their own 20 with a 3-point lead, worth 0.19 Win Probability (WP). A missed attempt hands the ball to the Bucs at their own 22, worth 0.17 WP. (If you're paying attention, you noticed that making the field goal is only worth +0.02 WPA.) The total WP for the FG attempt is:
0.88 * 0.19 + (1-0.88) * 0.17 = 0.19 WP
As mentioned, going for it in this situation will be successful about 14% of the time. A TD takes a 1-point lead, handing the ball to Tampa near their own 20, worth 0.51 WP. A failed conversion attempt is worth 0.22 WP--more than a made FG! In total, the WP for the conversion attempt is:
0.14 * 0.51 + (1-0.14) * 0.22 = 0.26 WP
So going for the TD, then and there, is the better decision, all other things being equal. Admittedly, 4th and goal from the 15 is very unusual. There just aren't many examples to use as a foundation for the 14% conversion rate, but 14% is not unreasonable at all. It's mostly based on extrapolated and regressed 3rd down data. To make the FG attempt worthwhile, you'd have to drive the conversion probability down to a break-even point of...well, there is no break-even point. It would never be a good idea to try the field goal, because the way typical coaches tend to call games, it would be better to simply take a knee on the 15 than try the field goal.
As crazy as it sounds, this odd situation can be explained by three heuristic errors. First, FGs are not automatic. Coaches need to get in the habit of saying "send in the FG attempt unit." Second, Atlanta head coach Mike Smith failed to consider that the consequence of a conversion failure is not fatal. In fact, it's better than making a FG. Teams with 6-point leads play more conservative than those with 3-point leads. And teams down by 6 play more aggressively than teams down by 3. Lastly, I think Mike Smith fell to the conjunctive fallacy, a logical error to which Buccaneers coach Raheem Morris has fallen victim in the past. By trying the FG, Smith was counting on:
1. Making the kick
2. Preventing a TB score and getting the ball back
3. Driving back in FG range
4. Making another FG
5. Scoring first in OT, which requires:
a. (Half the time) Making another stop
b. Driving into FG range again, and
c. Making a third FG, or scoring a TD.
That's a lot of things to go right, all in a row.
The difference between the FG miss WP of 0.17 and the failed conversion WP of 0.22 is 0.05, a considerable amount for merely 7 yds of field position. But those 7 yards are critical in terms of making a prospective FG. Assuming you get the ball back, those yards might mean the difference between getting within the mythical 'FG range' or not, or assuming you do, the difference between a 50% kick and a 63% kick.
The conventional thought process is "Let's just try to play for the tie here, and we'll roll the dice in OT." But the right idea is "Let's roll the dice here to take the lead, but if we fail, we've still got about the same chance to win as if we tried a FG."
As it turns out, Atlanta made the FG, but never saw the ball again, falling to the Bucs 16-13.
published on 9/26/2011