Which MLB teams have underperformed or overperformed against expectations?

Significantly better than expected

It would be different franchises each year, but a group like this probably emerges in the first month of every season. It's all to do with the always-hard-to-predict middle of the pack. As you'll soon see, our expectations at the very top and bottom of our Power Rankings have more or less played out, but the middle is a lot harder to judge. The New York Yankees, Chicago Cubs and Boston Red Sox were in that 10-to-20 range to start the season, but they've emerged a bit — the Yankees and Cubs into the top 10, and the Red Sox at least into the top half. The Kansas City Royals are kind of outliers who were expected to remain among the worst teams in baseball but have so far showed themselves to be at least fringe playoff contenders.

For the Yankees, Red Sox and Royals, the reason seems to be pitching. Those three teams rank top five in the majors in ERA. The Yankees have done it without Gerrit Cole (Clay Holmes has been awesome, Carlos Rodón has been resurgent), the Red Sox have done it with five starters on the IL (Tanner Houck and Kutter Crawford have been great and Rule 5 pick Justin Slaten has helped solidify the bullpen), and the Royals have gotten ace-level production out of Seth Lugo and Brady Singer (while second-year closer James McArthur has been effective in the ninth).

The Cubs haven't had the same level of overall pitching, but new ace Shota Imanaga has been elite, new first baseman Michael Busch has raked, and fourth outfielder Mike Tauchman has stepped up big-time in the absence of Cody Bellinger and Seiya Suzuki.

A little better than we thought

Here are similar results from three different situations.

The Cincinnati Reds were always difficult to predict. Their strength is in their youth, and their roster was hit with significant injuries — Nick Lodolo, Matt McLain, TJ Friedl — before the season even began. Elly De La Cruz has been awesome, and the Reds have played pretty well. We're buying them a little bit, but we're not racing them up the charts just yet.

The Detroit Tigers are a more traditional slightly better-than-expected team. Tarik Skubal is, in fact, a stud. Riley Greene, Mark Canha and Kerry Carpenter have hit. Casey Mize, Jason Foley and Shelby Miller have pitched. They clearly have our attention a little more than they did a month ago.

The Oakland A's have been maybe a little better than expected, but there might also be a few more really bad teams than we expected, and that race to the bottom has made them look better by comparison.

Here, we have 13 teams — 43 percent of the league — within two spots of their preseason Power Rankings, and most of them come at the extremes. Five of our bottom seven teams have been stuck there basically from day one, and six of our top 10 were also in the top 10 on Opening Day. (Furthermore, three of our top four are still in their original spots.) There's been some minor fluctuation, but generally speaking, we're pretty convinced about the best of the best and the worst of the worst.

This status quo group includes only two teams that are strictly middle-of-the-pack. The Minnesota Twins and Toronto Blue Jays have basically swapped places in the first month of the season, and it's still pretty hard to know what to make of them. The Twins, in particular, have dipped previously, but a magic sausage and a cushy schedule —sweeping the White Sox and Angels — helped them regain ground.

Also, it's worth noting the White Sox dropped only two places because that's the lowest they could go. If we were allowed to rank the Baltimore Orioles' Triple-A roster ahead of them, we probably would.

A little worse than we thought

Mets

17

20

-3

Cardinals

18

23

-5

Honestly, is there that much difference between the low teens and early 20s? Fighting for .500. Out of the playoff picture. It's just a difference of degrees.

According to FanGraphs, the New York Mets' playoff odds have gone up (though they're still well below 50 percent), while the St. Louis Cardinals' playoff chances have dropped about 15 percent due to their struggles and the emergence of the Cubs and Brewers as early NL Central standouts.

Both the Mets and Cardinals have underperforming lineups. Pete Alonso is basically the only true everyday Mets player with an above-average OPS+, while the Cardinals are getting little out of their supposed-to-be-deep outfield and their used-to-be-superstars corner infielders. Paul Goldschmidt's lack of production has been especially problematic.

Significantly worse than expected

The most notable fall here is surely the Arizona Diamondbacks, who came into the season riding high on a National League pennant and an aggressive offseason. But new starter Eduardo Rodríguez has yet to pitch, Jordan Montgomery was a late arrival, Merrill Kelly got hurt, and Rookie of the Year Corbin Carroll has struggled in his sophomore season. (There's also some bad luck in play because the team's run differential suggests they should be better than sub-.500.)

The Tampa Bay Rays, too, have fallen from near the top of our rankings, in part because their limitless supply of pitching seems to have run out. (They're not hitting much, either.)

The San Diego Padres and San Francisco Giants were anticipated to be on the fringe of playoff contention, but they've so far fallen below that standard. Logan Webb and Jordan Hicks have been great for the Giants, while Dylan Cease and Robert Suarez have been terrific for the Padres, but neither team has really gotten over the hump to keep our voters believing in their chances.

In any other year, the Miami Marlins' terrible start might have knocked them all the way to 30th in our rankings, but alas, the White Sox.

Biggest underachievers

Astros

3

19

-16

The biggest move in our Power Rankings has been the rapid descent of the Houston Astros (and, frankly, there's a case to be made that we're still giving them too much benefit of the doubt given that they were one of just four teams stuck on single-digit wins).

Thanks to Jose Altuve, Kyle Tucker, Yordan Alvarez and Jeremy Peña, Houston has maintained a good offense — enough to overcome Alex Bregman's struggles and Jose Abreu's frankly unplayable production — but the pitching has been a mess, in large part because of injuries throughout the rotation. Their starters have been unavailable, and their key relievers have been unbelievably bad.

If you think you're surprised by the Astros' fall, imagine how we feel after ranking them third on Opening Day.

(Top photos of Jose Altuve and Willy Adames: Mary DeCicco / MLB Photos via Getty Images and John Fisher / Getty Images)

Chad Jennings is a staff writer for The Athletic covering the Boston Red Sox and Major League Baseball. He was on the Red Sox beat previously for the Boston Herald, and before moving to Boston, he covered the New York Yankees for The Journal News and contributed regularly to USA Today. Follow Chad on Twitter @chadjennings22