As one of the ones that's been saying that we had a top 10 defense the last 13 games (when looking at yardage), I went back and re-checked my numbers. I had gotten my original numbers from the game by game stats from NFL.com. But after checking on that, it looks like I might have been picking up the NET passing yardage instead of the GROSS.
This time, I took the totals from NFL.com and then got the rushing and (GROSS) passing numbers from the game by game pages for the first 3 games only. I removed those totals, got the averages, and then calculated for 16 games.
I come up with 190 ypg passing and 112 ypg rushing. Those would have ranked us 9th against the pass, 12th against the run, and 11th overall. JUST outside the top 10. But much better than where we ended up.
Now, the question of whether using yardage as the standard because it's not the best indication of a winning team is irrelevant to me. When comparing defenses, yardage and points are what's usually used. Those are the standards. The Raiders had a strong defense and it shows in their stats even though they were a bad team overall and they got no help from their offense.
On the points side, we averaged 20.6 ppg the last 13 games of the season and 32.7 ppg the first three. But if you mix everything together, we averaged 22.9. Although that's better, we ended up just in the middle of the pack. Of course, that doesn't take into account points given up by the offense (3 td's, iirc) or special teams (1 td, iirc.) But everyone has those sorts of things in their stats and the defense is the driving factor, so I'm not too worried about that (although it would be interesting to see the scoring averages with non-defensive scores removed.)