Brian Nemhauser·
Advanced Stats
··3 min read

Turnover Margin Not All It’s Cracked Up To Be

Pete Carroll may need to reexamine his mantra. It may, in fact, not be “all about the ball.” Seattle has had an odd season in many regards. One such example is that the Seahawks have lost every game when they have won the turnover battle, and lost three games when they lost the turnover battle. Seattle had been 33-9 during the Carroll era when being positive in turnover margin, good for a 0.786 win percentage. Here’s the thing, though. That has not been the best barometer of Seahawks success, and it is not really even close.

Double-click on turnover margin

Over the past three years, the Seahawks are 16-6 when they enjoy a positive turnover margin. That is healthy 0.727 winning percentage. What may surprise you is that they are 5-2 (0.714) when they have a negative turnover margin. They were 2-2 before this season, but even that is a 0.500 record. That does not exactly paint the picture of a key indicator of team success.

Two new contenders for top stat

I catalog every Seahawks game and track a bunch of stats that are not easily accessible online. Two such stats are explosive play differential and third down percentage differential. They are both exactly what they sound like.

Explosive play differential

Explosive plays, as defined by Carroll, are pass plays of 16+ yards and rush plays of 12+ yards. The differential is simply the +/- of Seattle’s total minus their opponents. Take a look at how Seattle fared when they had a positive explosive play differential:

Year Record Win %
2013 11-2 0.846
2014 11-2 0.846
2015 3-1 0.750
Totals 25-5 0.833

And now look at how they fared when that differential was negative:
Year Record Win %
2013 2-1 0.667
2014 0-2 0.000
2015 0-2 0.000
Totals 2-5 0.286

That is a significantly higher winning percentage, when positive, than when Seattle has had a positive turnover margin, and a significantly reduced winning percentage, when negative, than when Seattle has had a negative turnover margin. It is also far less left to chance. The Seahawks could force a fumble and have it bounce the wrong direction. Teams have put together some incredibly conservative game plans this season that all-but-eliminated the chance of a turnover, but killed their chances to win by never challenging the defense down the field.

This is one I tend to consider the primary barometer of how the team played. It takes a very screwy game for Seattle to have a strongly positive explosive play differential and lose. An example would be in St. Louis last year when the Seahawks were +8 in explosive plays, but lost to the Rams in large part due to special teams. A flaw in explosive play differential is that special teams are not accounted for. It is really a measure of how the offenses are performing versus their opposing defenses. More often than not, that will align with who is winning overall.

Third down percentage differential

A new stat I started tracking in 2013 was third down percentage differential. It simply looks at which team finished the game with a higher third down conversion percentage. It has been surprisingly aligned with Seahawks results.
Seattle is undefeated this year when they finish the game with a higher third down percentage than their opponent. Their overall record in such games since 2013 is astonishing:
Year Record Win %
2013 11-1 0.917
2014 10-2 0.833
2015 3-0 1.000
Totals 24-3 0.889

Consider that during the same period, the Seahawks winning percentage was just 0.727 when they won the turnover battle. This is a nearly 90% win rate when winning the third down percentage battle. Coming up negative in that differential is not quite as damning as a negative explosive play differential, but it is not pretty either.

Year Record Win %
2013 2-3 0.400
2014 2-2 0.500
2015 0-4 0.000
Totals 4-9 0.308

It has, however, been a perfect predictor of this season for the Seahawks so far. They are undefeated when their third down differential is positive, and have yet to win when it is negative.

Deprecating turnover margin

Nobody should expect Carroll to eschew from his “all about the ball” mantra anytime soon. He is a student of the game and a progressive coach who looks at advanced stats. I am certain he already tracks explosive play differential, and it would not surprise me if he does the same with third down differential. 
He spends a lot of time talking about how their language leads their actions. It seems to me that speaking more about third downs, in particular, would be wise. More focus and better results there clearly have a massive impact on the outcome of these games. 

post signature