Perhaps no single factor in football is determines a game's, or season's, success rate quite the way turnover margin does. Finish plus-three in a game, and it's an almost guaranteed victory. Finish minus-three, and it becomes the opposite. Texas defensive coordinator Manny Diaz was a fan of saying after he took the Texas job that had the Longhorns been plus-12 in the turnover margin for 2010, rather than minus-12, Texas might have had another 10-win season.
In fact, while it isn't a perfect indicator, there's a reason the Big 12's worst team over the last four years (Kansas) hasn't had a single positive turnover ratio for those four seasons. And Kansas State, which often doesn't have the talent of other Big 12 schools, keeps itself afloat on turnovers. Note that the Wildcats' only negative season came in 2008, Ron Prince's last year as a coach. In the four years since Bill Snyder took over, Kansas State has been plus-42 in the turnover margin.
Likewise, look at the league champs each year. Last year, Kansas State won the title while having a plus-19 margin. In 2011, it was Oklahoma State at plus-21. In 2010, Oklahoma was at plus-14. In 2009, Texas was at plus-9. And in 2008, Oklahoma was at plus-23.
So here's everyone's turnover margins for the past five years. The first number is a team's 2012 turnover margin and counts down through each team's 2008 turnover margin. Then, I look at a team's five-year mark.
1) Oklahoma State: +0, +21, +12, +0, +5 — Plus-38
T-2) Kansas State: +19, +12, +4, +7, -7 — Plus-35
T-2) Oklahoma: -4, -2, +14, +4, +23 — Plus-35
4) Baylor: +2, +5, +0, -5, +16 — Plus-18
5) Texas: +5, +0, -12, +9, +2 — Plus-4
6) Iowa State: +0, -11, +6, +4, +4 — Plus-3
7) Texas Tech: -13, +1, -3, -6, +8 — Minus-13
8) Kansas: -3, -5, -8, -5, +3 —Minus-18
No major surprises, right? Texas was a plus turnover team, then went negative for the 2010 season, then was mediocre in 2011 and took a step forward in 2012. One interesting trend to watch: look at the downward spin of Oklahoma. The Sooners were a whopping plus-41 in the three years from 2008-2010, but are just minus-6 since. At the same time, Oklahoma State was plus-35 in its two really strong years in 2010 and 2011, only to fall back to zip last year. Oklahoma State holds an interesting distinction: the Cowboys are the only team not to have a negative turnover margin in any of the last five years.
Gamblers often look at turnover margin when trying to determine which teams will rise, or fall, the next season. While some teams (like Kansas State) are typically good at retaining the ball and forcing mistakes and won't fall off the map, you can look for other outliers, because the average team often falls back to zero (or worse) the next year. Look at Baylor. The Bears threw up plus-16 in 2008, only to come crashing back with a minus-5 the next year. Oklahoma State had two huge years in a row, but bookended those seasons with a pair of years at dead even.
With that in mind, keep an eye on Kansas State this year. The Wildcats will likely still have a positive turnover margin, but should struggle to replicate the plus-19 they threw up this year. On the other side, watch out for a rebound from Texas Tech. The Red Raiders were minus-13 last year, and don't figure to lose the margin by that much (if at all) in 2013.