Coaches will agree the most important statistic of all is the number of wins. Sure, time of possession and turnover differential are important, but one statistic that is very revealing, but highly misunderstood, is passing efficiency.

First, what is it and how is it calculated? Well, the number that results from the calculation measures just what it says–how efficient a QB, or team, is in passing the football. The NFL and the NCAA calculate passing efficiency differently, so much so that a passer rating of 100 is considered outstanding in the NFL, but is barely worth mentioning in the NCAA.

The NCAA formula is as follows:

[{(8.4 X yards) + (330 X touchdowns) – (200 X interceptions) + (100 X completions)}/attempts]

The formula was derived in 1979 using statistics from the previous 14 seasons. Mathematically, the formula was set up this way so that an average passer would have a rating for yards-per-attempt and completion percentage of 100. The multipliers of 330 and 200 were chosen to essentially cancel each other out for the average passer. (Yeah, for more on that, you might want to consult the wonderful world of mathematics. Too much for us here to get into.) So, in 1979 a passer rating of 100 at the NCAA level was average. Nowadays, with the improvement in passing statistics, efficiency ratings have improved and ratings as high, or higher than 180, are common. Baylor’s Robert Griffin III, a Heisman Trophy contender, has a passer rating of 211.3 (a new NCAA record). He has completed 72% of his passes and thrown 38 TDs compared to only 7 INTs. The statistics show that he has been very efficient as a passer. And that efficiency has helped his Baylor team to an outstanding season in which the Bears defeated Oklahoma and Texas for the first time in, well…forever!

Now we all know about teams like Baylor with their spread offenses and how they throw the ball all over the field. But what about teams that rely more on the ground game? Consider Tevin Washington of Georgia Tech and Tim Jefferson of Air Force. Both teams run the triple option offense. Both are near the top of the rankings in team rushing offense per game. But, Washington has a passer rating of 153.5 and Jefferson’s is 155.1. Considering that Brandon Weeden (of pass happy Oklahoma State) has an efficiency rating of 159.1, I’d say that the triple option passers are pretty efficient when they throw the football. Again, their efficiency has something to do with the success of both programs. Georgia Tech finished 8-4 and will play in the Sun Bowl while Air Force went 7-5 and will play in the Military Bowl.

Look at some of the passer ratings that are not so good. Ryan Griffin, QB at Tulane, finished with a rating of 112.8. Not so great a year for Griffin or the Green Wave, who finished 2-11. Chase Rettig, sophomore QB at Boston College, had a rating of 112.4. He completed 54% of his passes, threw 12 TDs and nine interceptions. The Eagles went 4-8. So passing efficiency may have something to say as to team success.

The NFL computation is similar but the big difference is the NFL values are capped. There are caps for completion percentage, 30% on the low end and 77.5% on the high end. What that means is a QB who completes 90% of his passes gets the same score as the QB who completes 77.5%. Likewise, a QB who goes 1-for-10 will have the same score as the QB who completes 30% of his passes. Another difference is the weight for yards per attempt–NFL is 4.17 and the NCAA is 8.4. Because of these disparities, the NFL rating will be lower.

Examine Aaron Rodgers of the defending Super Bowl champion, Green Bay Packers. He is having a phenomenal year leading the NFL is passing efficiency while his Packers are 12-0 and chasing destiny. He has completed 71% of his passes, thrown 37 TDs and just five interceptions. His league-leading passer rating? 125.3. Even Tom Brady, hailed by many as the best QB of the past decade, has a passer rating that may make one scratch his head…105.9. And he is ranked second, behind Rodgers, in the NFL.

So, the numbers may be a little different, but clearly what they measure is right on. Teams with QBs that are efficient in throwing the football have a greater chance at success than those who do not. For more on passing efficiency go here.