Numbers Game: Nebraska’s 6-Year Turnover Problem

Last October, two weeks after Nebraska had been blown out by Ohio State while committing four turnovers, I wrote a story titled “Nebraska’s 5-Year Turnover Problem.” As the title suggest, it was a long-range look at just how turnover-prone the Huskers had been since 2007.

Now, a week after turnovers cost the Huskers a shot at the 2013 Big Ten title, turnover numbers are a hot topic once again. Nebraska is  on the losing end of the turnover battle this season, again, and will likely have a negative turnover margin at the end of the year for the fourth straight season and the sixth time in the past seven seasons.

So welcome to Nebraska’s 6-year Turnover Problem. It’s still a thing.

And what’s interesting about it — the thing I wished I’d hit on more last year — is the correlation between turnovers and winning. Note that it’s not causation — there are too many factors that contribute to winning or losing a football game for it to always be that simple — but the correlation is still pretty strong.

Over the Huskers’ last 90 games, every game since the start of the 2007 season to now, they are -45 in total turnover margin (-0.5 TO Marg./G). Either way, total or per game average, that ranks 117th out of the 120 teams that have played FBS football for that entire span. Washington State (-0.639 TO Marg./G) is the only BCS conference school below Nebraska.

The strange thing is that, over that same span, Nebraska’s winning percentage is .667, which ranks 25th nationally. To give you an idea of how rare that is, here are two scatter plots showing all 120 teams’ turnover margin per game as well as their winning percentage between 2007 and now. (Hover over the dots to reveal the team name, national rank, turnover margin per game and winning percentage.)


Turnovers and Winning

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The top graph here is sorted by turnover margin per game, meaning it shows winning percentage relative to turnover margin. I divided the 120 teams into thirds to better show how a good (national rank 1-40), average (41-80) or poor (81-120) turnover margin relates to winning games. If you were to apply a trend line to that graph, it would basically conform to what most would expect, sloping right to left with the winning percentage decreasing as the turnover margin moved from positive to negative.

The bottom graph simply changes the sort to show where the top-, middle- and bottom-ranked teams based on winning percentage fall on the turnover margin scale.

Then there’s Nebraska — the red dot — which is an almost total outlier, falling relatively high up on the winning percentage axis but far to the left (i.e. negative) on the turnover axis. The Huskers win more games than you’d expect for a team that consistently loses the turnover battle and it’s not really close.

Of the teams in the bottom-third nationally in turnover margin per game, South Carolina is the one with the closest winning percentage (.670) to Nebraska’s, but the Huskers (-0.5/G) lose the turnover battle at four times the rate the Gamecocks (-0.125/G) do. The next closest team on the winning percentage scale is West Virginia (.663) and the Mountaineers, not surprisingly, have a positive turnover margin (.270).

Approach it from the other direction and things don’t get any closer. There are seven teams, Nebraska included, that have won 60-percent or more of their games with a negative turnover margin. Of that group, only two teams even approach the Huskers’ terrible turnover rate. Fresno State is the closest, winning 62.1 percent of its game while having a -0.425 turnover margin per game. Texas Tech is in the ballpark, winning 64.8 percent of its game while having a -0.341 turnover margin per game. There are only two BCS conference schools, Colorado and Washington State, that actually turn it over as much or more than Nebraska. Their combined record since 2007 is  49-118 (.293).

Some percentages to consider:


Behind the 8-ball

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Using the percentages shows the correlation between losing the turnover battle and losing games, or vice versa, even more clearly. Which begs the question: What would Nebraska — a team with a good winning percentage but horrible turnover margin — be capable of if it could start winning the turnover battle or simply get even?

That’s a question that becomes even more pressing with every passing, and typically turnover-filled, year. Under Bo Pelini the Huskers have succeeded almost in spite of themselves.

It’s a tough way to win football games and you have to think that eventually it will catch up with Nebraska if it hasn’t already.