How Completion Percentages Translate

Successfully scouting an NFL prospect is a task of Herculean proportions, problematic on two fronts. On one front, it is an immensely difficult task to predict how a player will perform once the chaff has been separated from the wheat and he is only facing the nation's best players. In addition, those who do the actual drafting, namely coaches and general managers and owners, allow themselves to overly romanticize the tangible measurements of a player (i.e.,height, weight, bench press, 40-yard dash time, and arm strength) and give those attributes more credence than they deserve. NFL personnel usually do that at the expense of paying attention to the actual productivity the potential NFL player had at the college level. Perhaps no position better exemplifies the trap draftees fall into time and time again than quarterback.

What I have sought to do in this post is to prove that what a quarterback does at his college directly reflects what you can expect the quarterback to do when he is allowed to start an extended number of games. Mostly, I am concerned with the quarterback's college completion percentage in comparison to his NFL completion percentage as I think completion percentage is the most important statistic to describe how good a quarterback is. Yards per pass attempt is nice, but no quarterback story can be told without first mentioning his completion percentage.

Not wanting to look at every single starting quarterback, I chose eight starting quarterbacks in what I have no doubt is a pretty good representative sample of all the quarterbacks who have been starting over the past couple years. The quarterbacks are as follows: Ben Roethlisberger, David Carr, Joey Harrington, Chad Pennington, Marc Bulger, Drew Brees, Tom Brady, and Aaron Brooks. In this sample are four first-round picks, one second-round pick, one fourth-round pick, and two sixth-round picks who have had varying degrees of success in the NFL.

Even though there are apparent differences between the eight quarterbacks, there is one overarching similarity, which is that none of the quarterbacks have put together an NFL completion percentage that is statistically significantly better than the one they amassed while matriculating at his respective university. Only one, David Carr, has an NFL completion percentage that is statistically signifcantly worse than his college one. For the rest, there is no really discernible difference between the rate at which they completed passes in college compared to how they are now doing on the professional level.

Those who find themselves armed with this knowledge will find themselves with a built-in advantage over those who continue to drool over a quarterback's arm strength. This is not to say that there is not a single NFL quarterback who has out-performed his NCAA days, although I think that is extremely unlikely, although the Denver Bronocs no doubt Jay Cutler (proves himself the exception to the rule I proved.

NOTE: The data did not include NFL postseason games or NFL games where the quarterback attempted fewer than 15 pass attempts.