Arizona to me seems a prime candidate for regression, at least on offense.
- Their advanced metrics are not good. They are 22nd in yards/play on offense. and 11th on defense. They were 18th in DVOA last week. They have the lowest offensive play success rate in the league.
- Aaron Schatz at FO pointed out that they have been terrible on first and second downs (ranked 26th and 31st) but great on third/fourth downs (ranked 6th). Converting a lot of 3rd-and-longs is probably unsustainable.
- They have a very boom/bust passing offense. They are 31st in completion % but 4th in yard/completion. That suggests they throw a lot of deep passes, and indeed they are 5th in pass plays of 20+ yards. That sort of offense tends to be very high variance, and they have been riding the hot side of the variance. The Eagles game was an extreme example of this: Palmer was only 20/42, but they hit 80-yard and 75-yard TDs. Eventually they're going to have games where they don't hit the big plays and when that happens they will struggle.
- They have an an unsustainably good turnover rate. Their QBs have thrown only 2 INTs all season, and their INT% is 0.7, both of which are best in the league. They are tied for fewest turnovers. Their INT rate is especially remarkable in light of their down-field passing attack -- their offensive style is the opposite of an Alex Smith making only safe throws to avoid turnovers style. Their INT rate is going to go up.
- For a team that likes to throw deep and has an unheralded offensive line and a non-mobile QB, they have given up surprisingly few sacks. They are 8th in sack rate and 6th in FO's Adjusted Sack Rate. They may not be able to sustain that either.
- Despite having a ton of positive variance, they are not blowing teams out. Even with hitting a lot of big plays while avoiding INTs and having the second highest turnover differential in the league, they haven't won any game by more than 11 points. So they don't have a lot of margin for error once the positive variance swing stops.
If there were a way to short football teams, I would be all over Arizona. Even with their hot start, I think they may struggle to get to 11 wins given how hard their schedule is: STL, DET, @SEA, @ATL, KC, @STL, SEA, @SF.