One bad hitter can drag down a lineup. Or the ball always finds the weakest defender. Sometimes, the best thing teams can do is shore up their biggest holes.

With the All-Star break approaching, we have a good sense of which teams have done the best at fixing their positional problems.

The following six teams feature positions that have improved the most from 2021 to '22 -- vaulting them either into contending status or to the top of their division.

Braves: Catcher

The defending World Series champion Braves’ catching corps has gone from worst to almost first this year, helping Atlanta keep pace with the Mets in the NL East.

The Braves sent out seven different starting catchers throughout the 2021 season, which was tied for the most in the Majors. As a whole, Braves catchers ranked second to last in the Majors and worst in the NL with a -0.6 WAR, per FanGraphs. They didn’t settle on a catcher until Travis d'Arnaud came back from injury in August.

This year, thanks to a solid d'Arnaud season and the emergence of William Contreras, the Braves' catching position not only has been a strong point but also one of the best all-around units in baseball. The Braves have jumped to second in MLB in FanGraphs WAR this season, behind the Alejandro Kirk-led Blue Jays and just ahead of the Cubs (fronted by William’s older brother, Willson Contreras).

Atlanta's doing it with the bat and glove. Their 21 combined home runs and 125 wRC+ are tied for second and second in MLB, respectively. They’ve also taken their framing to another level. Braves catchers -- thanks, in large part, to d’Arnaud -- are tied for sixth in the Majors in framing runs (3), per Statcast. Last year, they had exactly 0 catcher framing runs, which tied for 14th in baseball with five other teams.

The Braves are on pace for even more wins than in their World Series-winning season last year, and their catchers are a big part of why.

Cardinals: Second base

The Cardinals have trotted out an ensemble of second basemen this season, and it's paid off big time. Tommy Edman was the Cardinals’ primary starter at the position last season, putting up a solid 2.7 fWAR, and he remained there for the first month or so this season until shortstop Paul DeJong was sent down in mid-May. When Edman took over the Cardinals’ shortstop position full-time on May 20, he was putting up a 131 wRC+ with four home runs, nine stolen bases and excellent defense -- some of the top overall production for a second baseman in MLB.

Since then, his replacements -- Nolan Gorman with a sprinkling of Brendan Donovan -- have picked up right where he left off. Since debuting on May 20, Gorman has hit .252/.329/.450 while putting up a 1.1 bWAR in only 42 games. Donovan, who has played all over the field for the Cardinals, has an on-base percentage of .398 in 241 total plate appearances this season.

Cardinals second basemen have already hit as many home runs as they did last season (14) and have improved their slash line statistics significantly. The team’s second base trio has been the best group in baseball, according to FanGraphs WAR. That’s after finishing 20th last season. Edman’s improvement and standout rookie seasons from Gorman and Donovan have helped the Cardinals stay in the thick of things in the NL Central.

Padres: Starting rotation

After coming into last season with high expectations, the Padres' starting rotation fell apart. Blake Snell disappointed. Yu Darvish was inconsistent. Everyone, save for Joe Musgrove, dealt with injuries at times. Before the Padres knew it, they were trotting out Jake Arrieta and Vince Velasquez in September. After finishing below .500, San Diego had to improve its starting rotation in order to compete for the NL West crown in 2022.

That they have. The Padres didn’t sit on their hands -- they went out and added Sean Manaea, who’s provided stability and solid innings.

It’s their incumbents who have shined the most, though. Musgrove is pitching like a Cy Young Award candidate. Darvish has cut back on his walks and home runs allowed, posting a 3.53 ERA so far. After struggling in the Minors last year, MacKenzie Gore is pitching his way into the National League Rookie of the Year Award race. Mike Clevinger has only made seven starts, but he’s posted a 3.34 ERA in those outings after missing all of 2021.

As a whole, the Padres’ starters have a 3.54 ERA through July 8 -- a run lower than last year’s 4.54 ERA. That’s about as improved as you can get for a five-man rotation.

Guardians: Second base

The Guardians’ competitiveness in the AL Central has been one of the first half's biggest surprises. José Ramírez has a lot to do with that, but a fellow infielder has kept Cleveland in the hunt as well.

After a tough first year in Cleveland, Andrés Giménez has turned into one of the best second basemen in MLB. Giménez is slashing .298/.350/.484 with 22 extra-base hits after having just 15 last season in roughly the same number of games played. The 23-year-old second baseman has also cut down on his strikeout rate, which has fallen from 25.7% to 20.1%.

He’s done it by hitting a ton more line drives and making much better contact. Giménez has upped his line-drive rate to 27.7% from 14.5% while his hard-hit rate has gone from 30.4% to 41.3%. On the defensive side, Giménez continues to play a solid second base for a slick-fielding Cleveland team.

If the Guardians do, in fact, shock the baseball world by sneaking into the American League playoffs, you can thank Giménez. Cleveland’s offense has been solid after some dire preseason projections. Giménez hasn’t hit near the top of their order, but he’s provided some length behind the thump of Ramírez and Josh Naylor.

Mets: Outfield

The Mets spent big last winter to improve their outfield, and it’s paying off. Last season, manager Luis Rojas gave 1,319 plate appearances to outfielders Michael Conforto, Kevin Pillar and Dominic Smith. The trio combined to hit just 40 home runs and none of the three hit over .244, while Smith (a natural first baseman) also struggled defensively (-10 Outs Above Average).

The Mets replaced Conforto and Pillar with free agents Starling Marte and Mark Canha last offseason, while new manager Buck Showalter has limited Smith to first base and DH duties. The two newcomers are getting on base at a solid rate (.345 and .362 OBP, respectively) and providing a bit of pop (15 home runs combined). The pairing has added length to the Mets' lineup -- nearly every spot in the order features someone who can do damage.

The health of Brandon Nimmo and a rebound from Jeff McNeil have also been important. After being limited to 92 games last season due to various injuries, Nimmo has played in 75 of the Mets’ 84 games this season, posting a .363 OBP from the leadoff spot. McNeil is having his best season since 2019. He’s hitting .316 while splitting time between the outfield and second base.

As a group, the Mets' outfield has posted 8.2 fWAR, which is second only to the Astros. Last year, it put up just 5.2 WAR. The Mets' outfielders have everything to do with their division lead.

Twins: Shortstop

Free agency solved the Twins’ shortstop problem as well. Last year, Minnesota trotted out Andrelton Simmons for 131 games. It didn’t go well, in spite of his excellent defense. Simmons hit .223/.283/.274 with just three home runs in 451 plate appearances -- a big issue for a Twins lineup that struggled to score runs at times.

Minnesota went out and made, perhaps, the biggest upgrade of the winter by signing Carlos Correa to lead its infield. Despite a slow start, the gamble has paid off. Correa is having another terrific season, slashing .286/.360/.453, putting up a 134 wRC+.

While he hasn’t matched Simmons’ defense (-2 Outs Above Average), Correa's bat has more than made up for it. He has settled in nicely ahead of Byron Buxton in the Twins’ lineup, combining for one of the best middle-of-the-order pairs in baseball.

Correa has helped the Twins rebound from a disappointing 2021 season. They are, surprisingly, leading the AL Central by a few games over the Guardians. Minnesota’s offense has been a big reason why, too. It's scored 386 runs this season, which ranks fourth in the American League. There’s no telling if Correa will remain with the Twins after this season, but it's worked out for this one.