In the three previous posts, I have discussed my philosophy on how offense should be evaluated. This post will synthesize my past discussions and introduce what I have deemed Turnover Adjusted Offensive Efficiency (TAOE). TAOE is a calculation of all that can happen on a football field presented in the currency of yardage. Simply put TAEO adds penalty yards and turnovers to the box score to create what I feel is the most accurate measure of a team’s offensive performance. It also allows for the calculation of Turnover Adjusted Defensive Efficiency (TADE) which is calculated by taking 100-TAOE. TAOE like yards can be calculated game by game, the game totals can be summed to create a season long state. Again, we start with Yards Required to Score, (the distance from the end zone that the offense starts with the ball) and yards gained plus penalty yards gained or lost, essentially the endpoint of any given drive. This later calculation is divided by the former to give the raw offensive efficiency calculation on a given drive, and for the aggregate game itself. Next turnovers are considered. Using my previously mentioned turnover to yardage equivalency calculation (-Net Punting Average – Yards Beyond Original Line of Scrimmage Returned) (If the return does not pass the original line of scrimmage, the calculation is simply (-Net Punting Average + Distance to Original Line of Scrimmage) the yards gained plus penalty yards figure is adjusted for each drive. If there are no turnovers in a given game, then the figure is made the same, if not, the turnover adjustment is added or subtracted to the calculation. This new is then divided by the original yards required to score a touchdown number, giving us the Turnover Adjusted Offensive Efficiency.
We turn one last time to the Cowboys Bears Box score:
|Yards Required to score||Yards gained + penalty yards||Offensive Efficiency||Turnover Yardage Conversion||Adjusted Yards Gained||Turnover Adjusted Offensive Efficiency|
As you can see, the Cowboys gained 414 yards in the game, a nominally good outcome. This outcome shifts from good to average when Offensive Efficiency is considered, as the Cowboys gained less than half the yards necessary to score a touchdown every given drive. Next we consider turnovers, in this game Tony Romo threw five interceptions, so the adjustment is rather extreme, but it illustrates the point well. When turnovers are factored in the Cowboys performed as if they gained only 174 yards of total offense, which as any casual football fan can tell you is a putrid performance. The Adjust Yards Gained is then divided by the Yards Required to Score, giving a Turnover Adjusted Offensive Efficiency rating of 20.66508314 to Dallas. For a point of reference Baltimore in their season opener against Cincinnati had an TAOE of 74 and in their blowout loss to Houston had a TAOE of just under 10. By measuring TAOE against (1-TAOE) TADE can be calculated in this case Chicago had a TADE of 79.33 (the maximum being 100) a number that far better reflects their defensive performance than yards allowed, the stat the NFL uses to measure total defense. Further a Turnover Adjusted Efficiency (TAE) rating can be calculated by taking (TAOE – (100-TADE)). Throughout the course of the upcoming NFL season I will calculate TAE, and use it to create my power rankings. Note that it like any mathematical calculation is not effective until the sample size is large enough, and is not an effective gambling tool until all teams have played six games.