They're 13-3 and average 34 points a game while only giving up 21 points a game. Drew Brees is averaging 342 yards per game this season. Looks impressive, but let's go inside those numbers a little bit.
Home vs. Away
At home, the Saints are monsters. In their eight home games, they average a whopping 41 points a game, while their opponents only manage 18! (good luck with that Detroit). Surprisingly, Brees is averaging 328 yards in his home games, 14 yards less than his season average. I guess they're getting such big leads early in the game that he doesn't need to throw it late. The Saints are 8-0 at home.
On the road, it's a bit of a different story. Where they're ONLY averaging 27 points a game BUT their opponents are averaging 24.5. That's only a +2.5 differential compared to the +23 advantage they have at home. Brees is averaging a sick 356.5 yards per game in their away games, where the Saints have sustained all three of their losses this year.
Turf/ Dome vs. Outdoors
I was going to split this out with their Dome games vs. Outdoor turf games vs. Outdoor grass - but the only turf games they played this year came in a dome (no visits to the Giants, Bills, Pats, etc.).
Their dome game averages don't differ too much from their home averages. Their ppg drops to 38 and their opponents average about 20 (still good for a nasty +18). Brees in a dome throws for around 330 a game. Again not too different from their home games
Now, they've only played five TRUE road games, or games outside: Green Bay (opening night), Jacksonville, Carolina, Tampa and Tennessee. It's important to note: the weather conditions in all of these games were superb. I think the Tampa game might have had a little rain, but nothing too bad. Also the competition here isn't exactly elite either: only one playoff team in the bunch. In these outdoor road games is where they start to suffer. They're averaging 25.8 ppg and their opponents are at 24.4 - the closest differential so far at +1.4. Brees is averaging 370 yards, but they're 3-2 in these games.
Sure, they still have to annilhate the Lions next weekend before this is totally relevant. But just based on the numbers (before we even get to the part where we have a great defense and etc.) we should have a decent shot against these guys in SF.