TPS Advanced Stats: The Ballhawk Index

NFL broadcasters frequently describe certain players as “ballhawks.” It’s one of those terms that requires almost no explanation; anyone who hears it intuitively understands what it’s trying to convey: a ballhawk is somebody who’s around the football making good things happen for the defense.

Although it’s easy to understand what the word “ballhawk” means, quantifying it is a more difficult matter. What, exactly, does ballhawking entail?

Defining the stat

Thankfully, we don’t have to come up with an answer all on our own. The venerable Bob McGinn has already done it for us with a stat he kept unofficially for years as a beat writer. McGinn trotted out his “ballhawks” stat most recently in his preview of the Packers/Giants Wild Card round game in the 2016 playoffs, identifying Dominique Rodgers-Cromartie as the league leader in the stat.

In McGinn’s calculations, the NFL’s best ballhawk was the leader in the combined totals of interceptions, passes defensed, sacks, and forced fumbles. In equation form, the ballhawk stat looks like this: 

Ballhawks = interceptions + passes defensed + sacks + forced fumbles

What does it mean and why do we like it?

In short, the ballhawk stat measures how often a defensive player is around the football in a quantifiable way.  

Though many defensive stats can have weaknesses, getting to the football is never a bad thing. Granted, sometimes to get interceptions or deflect a pass a quarterback has to believe he could actually complete a throw in your direction, but if you’re a player of a certain level, defensive skill probably cancels that out in the long run. 

We like this stat because it shows who’s making the most statistically meaningful contributions. There is a blind spot in the stat towards players who are assignment sure but don’t necessarily put up big numbers or get their hands on a lot of footballs, and it also weights the contributions of defensive backs more than defensive linemen or linebackers.  

But generally speaking, we think this number does a good job of showing who’s making life difficult for defenses, especially through the air. Three of the four numbers tracked as part of the ballhawk stat are directly related to the passing game.

What does it tell us about the Packers?

According to the 2016 data, the Packers did not have a lot of defenders making consistent plays around the ball. Ha Ha Clinton-Dix was the only player from the Packers to rank in the top 30 on our Ballhawk Index, and he came in 29th.

Six different teams had multiple players rank higher than Clinton-Dix, including the very impressive New York Giants, who featured three players in the top ten.

Creating turnovers, knocking down passes, and sacking the quarterback are huge moments for any defense, and this stat illustrates exactly how infrequently the Packers did that in 2016. The Packers added a lot of talent to the defensive side of the ball this offseason. It will be interesting to see who, if anyone, makes a difference.