We don't see teams going back-to-back atop their divisions much anymore. If you're trying to understand baseball's current landscape, this is a good place to start.
In the past five seasons, 22 of 30 teams have played at least one playoff series. The American League has had five champions in six seasons, the National League four.
In the past 10 seasons, 13 franchises have been to the World Series. In that time, the Giants have won three times, the Cardinals twice and five other teams once apiece.
This is competitive balance in action. It stands to reason that it would be difficult for a team to win its division two straight years.
True that. The Rangers and Dodgers were repeat champs in 2016. Meanwhile, the Indians finished first for the first time in nine years, and the Cubs for the first time in eight.
Having said all that -- eloquently, I might add -- five of six 2016 division winners are very solid picks to win again in '17.
Let's line 'em up in the order of their likelihood of finishing first again:
1. Boston Red Sox
The Red Sox won 93 games and then added the most dominant player to change teams this offseason (Chris Sale). Got any other questions? Sure, there are some. Can Rick Porcello and Steven Wright repeat their 2016 performances? Can Mitch Moreland come close to replacing David Ortiz at first? In the end, though, there's no case to be made for any other AL East team. The Blue Jays and Orioles did not get better, and the Yankees are in transition. The Rays have a chance to be competitive, but they're not yet in the conversation with the Red Sox.

2. Cleveland Indians
This isn't a slam dunk. But it's close. Are Carlos Carrasco and Danny Salazar completely recovered from injuries that interrupted their 2016 seasons? When will left fielder Michael Brantley be back, and how good will he be? Will third baseman Jose Ramirez come close to repeating his amazing '16 season? The Indians are so good they don't need positive answers to all those questions. Fresh off playing Game 7 of the World Series, the Tribe added Edwin Encarnacion to play first and DH. The Tigers are good enough to push the Indians in the AL Central, and the Royals might be, too. In the end, though, it would be silly to pick anyone except Cleveland to win.

3. Los Angeles Dodgers
Press your nose against the glass and you can find a couple of reasons to doubt them. How many starts will Rich Hill, Scott Kazmir and Brandon McCarthy make? On the other hand, president of baseball operations Andrew Friedman has accumulated so much depth that manager Dave Roberts won't be counting on anyone (other than Clayton Kershaw) to carry a heavy workload. Shortstop Corey Seager may be the preseason NL MVP Award pick. The Giants have a chance to be very good, especially if Player Page for Matt Cain has a bounceback season and the young relievers get lined up behind new closer Mark Melancon. Meanwhile, the Rockies and D-backs are excellent candidates to be the surprises of baseball. For now, though, it's difficult to see the Dodgers not winning a fifth straight NL West title.

4. Chicago Cubs
If you would like to be cynical, you start here: The Cubs have a group of young position players and older starting pitchers. For instance, we just don't know yet how good Javier Baez, Kyle Schwarber, etc., are going to be. We also don't know when the workload will begin to take its toll on a rotation that was baseball's best in 2016. And the Cardinals and Pirates could both be good enough to play October baseball. But for every unknown the Cubs have, the Cards and Bucs have two or three. Until further notice, the Cubs are an easy pick in the NL Central.

5. Washington Nationals
There's no question the Nationals should be favored to win the NL East for the fourth time in six seasons. But unlike, say, the Red Sox and Indians, it's slightly less comfortable. For instance, what if all those Mets starters bounce back? What does the NL East look like then? Besides that, Nats general manager Mike Rizzo did not land a proven closer. OK, having dispensed with the required cynicism, let's be honest: This is the best team in the division. Best lineup. Very good rotation. Probably a really solid bullpen. Since Opening Day in 2012, Washington has been baseball's second-winningest team. The Nats have some unfulfilled postseason business, but they're looking to give it another try in '17.

6. Texas Rangers
The Rangers have not gotten better this offseason. The Astros, Angels and Mariners have. And Texas has so many questions, it's impossible to pick it higher than third or fourth. Can Yu Darvish stay healthy? The front three of the rotation -- Cole Hamels, Darvish and Martin Perez -- is solid, but another starter or two needs to emerge from a group that includes Tyson Ross, Andrew Cashner and A.J. Griffin. If the Rangers win again, it should surprise no one. They've been to the postseason five times in the past seven seasons and are fresh off a season when they overcame an assortment of doubts and injuries. But of last season's six division winners, Texas appears to be the least likely to repeat.