What Turnovers Really Mean

When I wrote about turnovers before the season started, I promised I would keep a close eye on them as the season progressed. I think it’s time to take another look.

In 2011, OSU gained a turnover on 4.0% of defensive plays (3rd in the country). The NCAA average is around 2.5%, so while it took an average team 40 plays to generate a turnover, our defense produced one every 25 plays.

As it turned out, last season’s offense was also pretty decent at holding on to the ball. We turned it over on 2.3% of offensive plays (49th in the country). Not great, but above average.

This gave us a per-play margin of 1.7% (5th in the country). That alone would give most teams a great chance at winning a lot of games. Look at the chart below. It shows the relationship between a team’s per-play turnover margin and winning percentage. The two have a fairly strong relationship (67% correlation). The line running through is a simple closest-fit linear trendline. It shows that a team with a +1.7% margin should have a winning percentage in the 75% to 80% range based on turnovers alone. Obviously, our team last year overachieved due mostly to our explosive offense.

Okay, so how are we doing this year? (Hint: not as good)

This year, we gain a turnover on 1.6% of defensive plays, or 1-in-62 plays. (104th).

We lose a turnover on 2.7% of offensive plays or 1-in-37 plays. (83rd).

Our per-play margin is -1.1% (104th).

Turnovers have cost us dearly in our losses, but our team is still overachieving the trendline. A -1.1% margin tells us that a team should have a winning percentage in the 35% to 40% area. We are sitting at 67% right now (see the orange dot in the chart).

K-State is having a very similar season to our 2011 adventure. They are leading the nation in per-play turnover margin at 2.8% (the dot closest to the top right — where you want to be — is K-State).

One more thing. I was curious to see if our change in per-play margin from 2011 to 2012 was the largest. It is. Last year we were +1.7%. This year we are -1.1%, so the change is -2.8%. UCONN is tied with us for the largest fall.