These are MLB's most improved units

Every season offers a fresh start for teams across the Majors, and we’ve seen a number of clubs take advantage of the opportunity, making significant improvements in areas that were weaknesses for them one year ago.

With the 2024 campaign more than a month old, let’s take a look at some of the most improved units in five different phases of the game -- offense, starting pitching, relief pitching, defense and baserunning. (All stats below are through Friday.)

Offense

Brewers
With ace pitcher Corbin Burnes being traded to the Orioles in February and All-Star closer Devin Williams going down with a serious back injury in March, the Brewers seemed likely to take a step back after reaching the postseason in five of the past six years. Milwaukee, though, is currently in first place in the National League Central once again. And unlike last year, the team’s offense has been the driving force behind its success. Despite getting modest production from top prospect Jackson Chourio and losing former NL MVP Christian Yelich to a back injury after 11 games, the Brewers rank fourth in the Majors in scoring (5.16 runs per game). The trio of William Contreras, Willy Adames and Brice Turang has been particularly impressive, combining for a 151 wRC+.

Guardians
One year after ranking among MLB’s lowest-scoring teams, the Guardians’ offense has fueled a surprising 20-12 start, helping the team overcome a subpar performance from a rotation that lost ace Shane Bieber to Tommy John surgery after two starts and has been without youngster Gavin Williams all season due to an elbow injury of his own. With Steven Kwan (.356 BA, .906 OPS) and Josh Naylor (7 HR, .857 OPS) carrying much of the load, Cleveland entered Saturday averaging the sixth-most runs scored per game (4.91) in the Majors.

Yankees
While Aaron Judge, Gleyber Torres, Anthony Rizzo and Giancarlo Stanton have yet to find their groove, the addition of superstar outfielder Juan Soto has made all the difference in the world for the Yankees’ offense. New York has jumped from 25th in scoring to 14th with 4.59 runs per game, making an especially large improvement when hitting with runners in scoring position. In 2023, the A’s were the only team with a lower OPS with runners in scoring position than the Yankees’ .677 mark. This year, the Yanks have an .834 OPS -- including a 1.317 OPS from Soto -- in those situations.

Starting pitching

Phillies
Philadelphia’s starting staff has gone from a middling unit (15th in ERA) last year to one of baseball’s best in 2024, and the club is running neck and neck with the powerhouse Braves in the NL East as a result. Zack Wheeler, Ranger Suárez and Spencer Turnbull, who joined the Phils on a Minor League deal in February, are all sporting sub-2.00 ERAs, while Aaron Nola has lowered his ERA from 4.46 to 3.32 year over year. The Phillies’ rotation ranks second in the Majors in ERA (2.54) and first in WHIP (1.01), innings (194 2/3), strikeouts (201) and opponents’ batting average (.197).

Red Sox
The performance of Boston’s starting rotation has been one of the biggest surprises of the young season. The Red Sox’s rotation not only has MLB’s best ERA (2.17) this season after ranking 22nd (4.68) a year ago, it has the eighth-lowest ERA through 33 games since earned runs became an official stat in both leagues in 1913. The Red Sox have done that despite losing their marquee free-agent addition, Lucas Giolito, to elbow surgery before the season began and dealing with injuries to Nick Pivetta, Garrett Whitlock and Brayan Bello. Kutter Crawford and Tanner Houck have been at the heart of the turnaround for Boston, combining for a 1.89 ERA with 86 strikeouts over 85 2/3 innings in 14 starts.

Royals
Although there are myriad reasons why the Royals have started off 20-13 this season after losing 106 games in 2023, the team’s rotation deserves a significant amount of credit. Kansas City’s starting staff has posted a 2.96 ERA -- the third lowest in MLB -- through 33 games in 2024, down from 5.12 (fourth highest) a year ago. The roots of that turnaround can be traced back to last summer, when the Royals acquired budding ace Cole Ragans from the Rangers in a trade for veteran reliever Aroldis Chapman. Kansas City’s free-agent deal with Seth Lugo has made a notable difference as well, along with Brady Singer’s rebound season.

Relief pitching

Athletics
Flamethrowing righty Mason Miller will get much of the attention when it comes to the A’s bullpen, and rightfully so, but he’s not the only member of Oakland’s relief corps who’s thriving. The club ranks second in bullpen ERA (2.47) and has MLB’s third-lowest percentage (17%) of inherited runners scored, one year after ranking 28th (5.20) and 29th (40%) in those categories, respectively. The A’s bullpen has been a big reason why they’ve started out 16-17. Oakland didn’t notch its 16th win until June 10 last year, by which point the team already had 50 losses.

Mets
The Mets’ bullpen floundered last season without All-Star closer Edwin Díaz, who missed the entire year after tearing the patellar tendon in his right knee during the World Baseball Classic. With Díaz sidelined, New York’s relief corps ended up ranking 22nd with a 4.45 ERA and 15th with a 23.6% strikeout rate. This year, the Mets’ bullpen is fourth (2.74 ERA) and first (30.8%), respectively, in those departments. While Díaz’s return has certainly helped, the Mets have also received an unlikely boost from 31-year-old journeyman Reed Garrett, who is 5-0 with a 0.54 ERA and 28 K’s over 16 2/3 innings.

Royals
Even with free-agent additions Will Smith and Chris Stratton allowing 20 runs in 23 1/3 innings combined, the Royals’ bullpen is significantly improved from where it was in 2023. Getting a lift from a pair of under-the-radar trade acquisitions -- new closer James McArthur was acquired from the Phillies last June, while setup man John Schreiber was picked up from the Red Sox in February -- Kansas City’s relief corps is tied for eighth in MLB with a 3.28 ERA and has allowed inherited runners to score at the second-lowest rate (16%) in the game. Last year, the Royals ranked 29th in bullpen ERA (5.23) with MLB’s fifth-highest percentage (37%) of inherited runners coming around to score.

Defense

Dodgers
The Dodgers’ defense was a source of consternation for the high-powered club during Spring Training, with Los Angeles deciding to move Mookie Betts to shortstop -- after previously shifting him from right field to second base -- in place of the struggling Gavin Lux. However, Los Angeles’ defense has been just fine, ranking sixth in Outs Above Average (+9) after tying for 17th (-4 OAA) in 2023. First baseman Freddie Freeman (-2 OAA) is the only Dodgers player (minimum 10 attempts) with a negative OAA figure.

Orioles
Although the Orioles won 101 games and the American League East title in 2023, their defense was a weak spot, recording -18 OAA. That’s changed in 2024, with Baltimore tallying +8 OAA (tied for the seventh-best figure in MLB) so far. The biggest difference for the O’s? Their worst defender from 2023, Adam Frazier (-15 OAA), is no longer on the roster, while their second-worst defender, Ramón Urías (-9 OAA), is now in a part-time role.

Twins
Minnesota shored up the right side of its infield by signing veteran first baseman Carlos Santana (+1 OAA in 2024) and making Edouard Julien (+3 OAA in 2024) its starting second baseman in place of Jorge Polanco (-7 OAA in 2023), who was traded to the Mariners in the offseason. Having Santana and Julien handling everyday roles has helped the Twins go from tying for 21st in OAA (-12) overall last year to ranking 10th with +6 OAA in 2024.

Baserunning

Giants
San Francisco had the fewest stolen bases (57) in MLB last season and still isn’t doing much in that department, but the team at least has gone from 26th (-10.1) to tied for 15th (-0.3) in BsR, FanGraphs’ catch-all baserunning stat that takes a number of factors into account, including successful steals, caught stealings, double plays grounded into and extra bases taken.

Nationals
The Nats have gone from being the 17th-best team in FanGraphs’ BsR stat a year ago (-3.2 BsR) to fourth best in 2024 (+3.6), in large part because they are attempting way more steals (2.03 attempts per game vs. 0.96) and succeeding at a higher rate (83% vs. 81%). The Reds (56 steals) are the only team with more steals than Washington (54) this season.

Twins
Like the Giants, the Twins remain one of the most conservative teams when it comes to stealing bases, but they’ve improved their baserunning nonetheless, going from -5.2 BsR (11th worst) to +1.8 (seventh best).