AP

There’s a reason some teams get bad and stay bad.

And instability at quarterback is one of the quickest ways to get there.

As pointed out by Jim Wyatt of the Tennesseean, the Titans are about to have a different leading passer for the eighth straight season.

They’re back to Jake Locker this week, with the former first-rounder getting a last crack after being replaced by rookie Zach Mettenberger.

But since the end of the Steve McNair era, the Titans have known only such changes over the course of the year. Here’s a list of their leading passers by year since the 2007 season.

2007: Vince Young (238-of-382, 2,546 yards, 9 TDs, 17 INTs, 71.1 rating).

2008: Kerry Collins (242-of-415, 2,676 yards, 12 TDs, 7 INTs, 80.2 rating).

2009: Vince Young (152-of-259, 1,879 yards, 10 TDs, 7 INTs, 82.8 rating).

2010: Kerry Collins (160-of-278, 1,823 yards, 14 TDs, 8 INTs, 82.2 rating).

2011: Matt Hasselbeck (319-of-518, 3,571 yards, 18 TDs, 14 INTs, 82.4 rating).

2012: Jake Locker (177-of-314, 2,176 yards, 10 TDs, 11 INTs, 74.0 rating).

2013: Ryan Fitzpatrick (217-of-350, 2,454 yards, 14 TDs, 12 INTs, 82.0 rating).

2014: Zach Mettenberger (107-of-179, 1,412 yards, 8 TDs, 7 INTs, 83.4 rating).

They’ve also had games started by players from Charlie Whitehurst to Rusty Smith over that span. And there have been a few good seasons. But the lack of a steady answer at the most position is the main reason they’re 30-47 over the last five seasons.