Statistics lie. They use them against us in all walks of life...just wait for the presidential election.
The answer is, stats lie.
Watch a Patriots game of the Brady era and it becomes clear. The Patriots secondary is under attack..because the Patriots opponent is behind. The statistical jive is a two to one pass to run ratio (which seems to happen in most Patriots games). Da fish and the Chargahs HAD to throw 45 passes each because Brady had already destroyed their secondaries.
Another reason the Patriots give up a ton of pass yards is because they are playing with the lead. Belichick plays with a twelfth defensive back...do you know who he is? He is the Patriots end zone. As Rivers and Henne march down the field, the field gets ....smaller. This leaves less real estate for the assorted defensive backs to cover in the pass happiest NFL in history. Belichick will cough up 14.2 yards willingly if the trade off is avoiding giving up 40 yards.
Don't listen to me, look at the statistics.....well, you know what I mean.