Bear Digest

The problem and beauty of Ben Johnson's new key football statistic

Analysis: Ben Johnson has said he no longer considers turnovers the key statistic in football and he explained Tuesday what is, but there are problems with this.
Gene Chamberlain|
Caleb Williams looks for a target against the Vikings last season. Looking for bigger plays is Ben Johnson's way to impact a key statistic.
Caleb Williams looks for a target against the Vikings last season. Looking for bigger plays is Ben Johnson's way to impact a key statistic. | Jeffrey Becker-Imagn Images

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Chicago Bears

Bears coach Ben Johnson made it clear during his introductory news conference how he no longer regards turnovers as the key number in determining the winner of a football game.

It's easy to see why he feels that way after he had a quarterback, in Jared Goff, who threw five interceptions against Houston and Detroit still won the game.

At the owners meetings Tuesday, Johnson revealed what he actually does regard as the key number, and analytics geeks will love it while traditionalists will say he's been playing around on-line too much.

It's expected points added, or EPA. This is the difference between a team's expected points before and after a play, quantifying the impact of each play on your team's point potential. Before anyone can even figure out EPA on given plays, you need to know the expected points before that play and after the play.

It definitely tends to complicate football when you're counting on that as a key number.

"The way I understand it right now from our analytics team, the EPA in the passing game is really one of the most critical factors in determining wins and losses right now," Johnson told reporters at the owners meetings on Tuesday. "That's probably changed over the last five years or so. I would have said five years ago turnovers, takeaways, that was No. 1. From what I understand now, that EPA for the passing game has now surpassed that.

"So whatever team has the higher passing game EPA at the end of the time, they generally win that game. It's over 80% of the time. So, it's a huge stat."

The critics of this thinking will point out how much more difficult it is to calculate this in a few moments the way a turnover statistic is.

Also, and more importantly, turnovers are plays naturally occurring in and of themselves within a game. EPA is, itself, a measurement determining probability and possibility and not an actual specific single play occurring naturally within a game.

A turnover is based on reality, like stripping the football or intercepting a pass or coughing up the football and throwing an interception.

EPA is calculation-based.

Johnson explained how they take advantage of knowing the importance of this statistic, though. At least in football, inflation is not a bad thing, it seems.

He said the Bears have "...looked to how do we help inflate that number (EPA): higher completion percentage, more run after catch opportunities. That's not to say we're not going to take our shots down the field and look for big, explosive plays and big chunks or touchdowns that way but there's a lot of ways we can get that done."

What is apparent from this is Johnson is trying to be proactive by using EPA. The turnover figure is more of a reactive number. You try to prevent turnovers. It tends to make coaches become more defensive. Using EPA makes them more aggressive, and this definitely fits Johnson's approach.

The real problem with Johnson's thinking here is getting EPA to work for him now, to get that offense being capable of inflating EPA with bigger plays, he will first need to have an actual offense functioning at an NFL level.

He had that in Detroit so it wasn't a problem.They're going to actually need to build it in Chicago before any analytics are beneficial.

Personnel-wise, they have made strides this way in free agency but it's only the practice field and in reality, rather than in analytics, where the entire thing needs to come together first.

Then Johnson can play with his calculator.

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Gene Chamberlain
GENE CHAMBERLAIN

Gene Chamberlain has covered the Chicago Bears full time as a beat writer since 1994 and prior to this on a part-time basis for 10 years. He covered the Bears as a beat writer for Suburban Chicago Newspapers, the Daily Southtown, Copley News Service and has been a contributor for the Daily Herald, the Associated Press, Bear Report, CBS Sports.com and The Sporting News. He also has worked a prep sports writer for Tribune Newspapers and Sun-Times newspapers.