Bad Decision Rate (BDR) is a metric from KC Joyner, the Football Scientist, that was recently featured prominently in ESPN The Magazine’s NFL preview issue.

Tennessee Titans quarterback Jake Locker had the lowest bad decision rate in the league in 2012 -- 0.6 percent.

BDR is the rate at which a quarterback makes a mental error that leads to a turnover opportunity for the D.

There is certainly some subjectivity in judging a mental error.

“But there are objective elements in place to reduce the subjectivity,” Joyner said. “Examples of mental errors include not seeing defenders in the passing lane, and throwing the ball while being tackled.”

How significant was Locker’s number last year?

“It's significant in that it is quite rare to see a quarterback post a BDR of less than one percent,” Joyner said. “Tom Brady is the only passer to reach that level on a consistent basis, so it would be quite surprising to see Locker stay at that level but even if he triples his BDR, it would still be below the 2 percent mark that serves as the bar for superior play in this metric.”

So what does Joyner project for Locker this year?

“I have him projected as posting a 0.8 percent BDR this year,” Joyner said. “That is based on his 2012 performance as well as his 2013 schedule, which is the most favorable in the league based on a defensive BDR perspective.”