But for most NFL teams, it's not that easy. The typical NFL team sees ups and downs over the course of a 10-year period, with multiple quarterbacks, multiple head coaches and multiple defensive stars coming and going.
Sometimes you can see the gradual growth of a top unit as stars get drafted and signed and then jell over the course of a couple of seasons. Other times, teams randomly hop to the top of the league with no warning.
What did the past 10 years of team trends look like for the NFL? We examined the biggest takeaways from a decade's worth of top-level data for every team. Below, we list the regular-season offensive and defensive DVOA for all 32 teams over the past decade.
DVOA measures how efficient offenses are at producing yards and points, with zero representing league average in each year. Since better defenses are preventing yards and points, defensive DVOA is better when it is negative, not positive. You can read more about how DVOA works here.
One of the most important discoveries of football analytics is that defense is less consistent from year to year than offense is. So one thing you'll find in the tables below is that the defensive numbers bounce around a lot more than the offensive numbers, and sometimes it is harder to find a good explanation for why defenses suddenly got much better or worse. Still, it's the NFL, so the offenses can be pretty inconsistent too. There's a lot of year-to-year change in this league!
Offense: For one shining year in 2015, it all came together for Bruce Arians and the Arizona offense. The Cardinals finished 13-3, scoring 30 points nine times during the regular season. Quarterback Carson Palmer was No. 1 that year in passing DVOA. The offense finished fourth, but that's partly because of a Week 17 game that meant nothing. Take that game out and the Cardinals would have finished with our No. 1 offense.
For most of the rest of the decade, though, the Cardinals' offense was below average, even in the other years when Palmer was the starting quarterback (2013-17). Early in the decade, the Cardinals were getting poor performance out of late-round or undrafted quarterbacks such as John Skelton, Ryan Lindley and Max Hall. Later in the decade, Josh Rosen in 2018 had the worst quarterback value of the past 35 years, according to Football Outsiders' DYAR metric. The contrast between these years and the Palmer years resulted in the Cardinals having the biggest standard deviation of any offense this decade.
Things finally bounced back again with the arrival of Kliff Kingsbury and Kyler Murray in 2019. The Cardinals ranked 13th in offensive DVOA for the season, including seventh from Week 10 on.
Offensive outlook for 2020: The bad news for the Cardinals is that better offensive performance in the second half of one season doesn't tend to carry over to the next. The good news is that quarterbacks tend to improve the most in their second season, meaning Murray is trending upward anyway. The chances of Murray having a breakout season got even stronger when the Cardinals traded for wide receiver DeAndre Hopkins.
Defense: The Arizona defense was unimpressive at the beginning of the decade and then took a huge leap forward into our top 10 in 2012. Some of this was the maturation of young stars including Calais Campbell and Daryl Washington. Some of it was the arrival of rookie cornerback Patrick Peterson. It wasn't a change in scheme, as Ray Horton coordinated the defense in both 2011 and 2012.
Horton was swept out with Ken Whisenhunt in 2013, but the Cardinals' defense continued to excel. Under the leadership of Todd Bowles and then James Bettcher, the Cardinals ranked in the top seven for the next five years, through their winning seasons in the middle of the 2010s. Chandler Jones and Peterson are still excellent, but the Cardinals lost a lot of the talent around them and the defense began to struggle again in 2018.
Defensive outlook for 2020: Things are looking up again for the Arizona defense, which acquired a lot of new talent this offseason. That includes free agents De'Vondre Campbell and Jordan Phillips as well as eighth overall draft pick Isaiah Simmons. A low turnover rate in 2019 is another harbinger of positive defensive improvement in 2020.