How bad was Philip Rivers' day?

I was going to look up this anyway, for my own curiosity, so I decided to make a post out of it.

If you listen to the Squadcast (the weekly podcast I do with Ben Higgins), you know that I like ESPN's QBR stat. We're going to focus on it here.

Against the Vikings, Rivers' had a QBR of 30.4. That's bad. Really bad. An average NFL QB this season is somewhere around 60 on the QBR scale, so imagine 30 being way before that.

When's the last time Rivers had a QBR of 30? Is it possible the game against the Vikings was his worst ever (or, at least, worst since QBR was invented)?

The short answer is no. In fact, we don't have to go very far back at all to find an even worse game: Week 17 against the Kansas City Chiefs last season, when he posted a QBR of 18.8 (throwing 2 interceptions and zero touchdowns).

But...that's just a throwaway game, right? Last game of the season, let caution fly into the wind! What about before that?

Ummm, the picture doesn't look much better. Actually, it makes a lot more sense if we look at the big picture here. Let's look at Philip's last seven regular season games by QBR, starting with the game against the Vikings and working backwards.

30.4
44.4
73.1
18.8
58.6
29.0
15.1

Yikes.

It gets better if you look at the first half of last year, so you could argue either that Rivers' offensive line has fallen apart since then, his back has fallen apart since then, or Frank Reich has been figured out since then. None of those options are very good.

Elite QBs have bad games all the time. Peyton Manning had a QBR under 30 against the Ravens in Week 1, and did it in Week 16 (and as well as in the playoffs) last year. Aaron Rodgers did it once last year, posting a paltry 12.4 QBR against the Buffalo Bills.

So, the Vikings game was not Rivers' worst game ever, but having 4 really bad games out of his last 7? That is more bad games than good ones. That is not what elite QBs do. Rivers has to find a way to make it right over the next couple of weeks.