According Advanced NFL Stats (http://www.advancednflstats.com/2009/09/4th-down-study-part-4.html) it is a net positive when you go for it when you have a 4th down with 10 yards to go or less between the opponent 39 and 43 yard line.
Lets look at Seattle’s opportunities so far this year and the result.
4th and 5 at Dallas 41 – Punt – downed at 5 yard line
Green Bay Game
4th and 4 at Green Bay 44 – Punt – downed at 1 yard line
4th and 3 at Carolina 39 – Punt – downed at 5 yard line
4th and 1 at Carolina 43 – Punt – downed at 9 yard line
San Francisco Game
4th and 2 at SF 43 – Punt – downed at 14 yard line
5 total punts.
Lets look at the effect of going for it on fourth down. The probabilities are from the website mentioned above. It measures each possession with the Expected Points (EP) resulting from that possession.
The average is 4th and 3, which is a 56% success rate. This adds 2.8 possessions based on 5 attempts. The Expected Points is 2.8 per possession from this distance, which adds 7.8 points or 1.6 points per 4th down attempt.
But we have to think about the defense also.
If we give up the ball to the other team at their own 40 yard line they have 1.3 EP and if we punt it to them they have 0 EP from the 15 yard line and -0.6 EP from the 7 yard line. Lets assume that long term they will start on the 10 yard line on average, which is -0.2 EP. So each time we go for it and don’t get it the other team has a positive swing of 1.5 EP. With 2.2 failed 4th down attempts (5-2.8) the other team will have scored a total of 3.3 points or 0.7 per 4thdown attempt.
Adding the offense (1.6) and subtracting the effect on the defense (0.7) results in a positive effect of 0.9 EP per 4thdown attempt. This nets to a total of 4.5 additional points this season through 7 games. Who wouldn’t take another 4-5 points in one of these barnburners?
People will say that the Seahawks have such a good defense that we should just punt. I say, we have such a good defense so we should risk giving the ball back on the opponent 40 yard line because the other team will likely still punt.
People will say that the punts were very successful with an average downed punt at the 7 yard line. It is true, they have been successful, credit given to Jon Ryan, but it doesn’t make sense to punt even if the starting field position averages the 7 yard line.
Another positive is that this will give the Seahawks more plays per game (4% more), which will result in more passes for Russell and more runs for Marshawn. It may mean one more pass to Sydney Rice per game, which may keep him from throwing his mouth guard on the turf.
Another positive is this keeps our defense off the field longer keeping them rested.
Many other coaches in the league punt in this situation as well. The Seahawks aren’t the only ones. Nevertheless, I think the coaches are wrong in assessing the risk in these situations. The effect is not so substantial, but the Seahawks should take these risks because they are worth it. And we will grab our seats and hold on for the ride.