You may have noticed this little tidbit in this week's ESPN Numbers Crunching piece.

Philadelphia is No. 1 in the league in offense and defense in third-and-long (seven or more yards to go).

Apparently, this comment has caused some disagreement from the Philadelphia faithful. According to Twitter user @wawarun (a very appropriate Philly username), Philadelphia Daily News correspondent Paul Domowitch (@pdomo) tweeted the following:

Opponents have converted 13 of 43 third downs of 8 yds. or more v. Eagles. FBoutsiders might want to redo their math.

Actually, we don't have to do re-do our math. What we need to do is go inside our math, as this disagreement shows the limits of a quick "here are some tidbits" column like Numbers Crunching.

The first thing you may notice is that FO's definition of third-and-long is different than Paul Domowitch's definition of third-and-long. We include any play with 7+ yards to go. He includes only plays with 8+ yards to go. When we say third down, we're also including passes and runs on fourth down. I assume he is not.

Philadelphia has allowed conversions on just two of nine third-and-7s this year. They've faced one play on fourth-and-long, an incomplete pass by Shaun Hill. In addition, I'm not sure how this is the case, but Domowitch's numbers seem to be wrong. Our database only lists Eagles opponents as 12-of-41. I'm not sure what plays we are missing, or if he's counting one twice. But when you add in our third-and-7 numbers and the single fourth down, we're now at 14-of-51, or 27 percent.

Can you guess what the league-wide conversion rate has been on third or fourth down with 7+ yards to go this year?

Yes, that's right, 27 percent. So if we are only judging by conversion rate, the Eagles haven't been bad on third-and-long. They have been average.

Then again, there is more to football than just conversion rate. Pick the ball off on third-and-long, and now you've gained field position because the other team can't punt the ball on fourth down. (Get a sack and fumble, and things are even better.) And the leader in turnovers in third-and-long situations is... Philadelphia, which has six picks in those 51 plays. (Cincinnati also has six turnovers, but one is a Hail Mary and another was a fumbled handoff by Carolina that they didn't actually force themselves.)

On top of this, let's look at the Eagles' opponents. Atlanta is fourth in DVOA on third downs. Detroit is sixth. Tennessee is eighth. Philly's average opponent has 8.1% DVOA on third downs. So they haven't exactly had it easy.

So the Eagles are average preventing conversions, but excellent on turnovers, and they've done it against a tough schedule. That's how we end up with Philadelphia number one in defense on third-and-long.