The postseason showcases the best of the best teams. But even those teams have weaknesses.
Here's the biggest weakness for every playoff contender this season.
(Teams are listed alphabetically. All teams still in the race are included.)
Astros: Catcher offense
Martín Maldonado is a strong defender, but his bat is one of the few holes in the deep Astros lineup. He's batting .173 in over 400 plate appearances with an OPS+ of 59 -- basically, he's barely been half as good as a league-average hitter. The Astros have gotten the least offense from the catcher position of any playoff team. And they have to play the White Sox in the Division Series. Chicago has gotten the most offensive production from its catchers of any team in baseball, led by Yasmani Grandal (159 OPS+). It's a competitive disadvantage for Houston.
Blue Jays: Third base
The Blue Jays are so strong across the rest of the infield: Vladimir Guerrero Jr. at first base, Marcus Semien at second, Bo Bichette at shortstop ... and then you get to the hot corner. The production just hasn't been there, especially in the power-hitting department. Cavan Biggio just returned from the injured list, but he's batting .215 and slugging .350 with seven homers in 77 games. His main replacements, Santiago Espinal and Breyvic Valera, have three homers in 128 games between them. The Guerrero-Semien-Bichette infield trio, by contrast, has 118 home runs.
Mariners: The lineup
Mitch Haniger and Kyle Seager are slugging homers (38 and 35, respectively), and Ty France has been good, but overall, the Mariners' lineup doesn't stack up to other postseason contenders. They rank last in the Majors in team batting average (.226), third-worst in on-base percentage (.302) and fifth-worst in slugging percentage (.386), and their 24.9% strikeout rate is fourth-highest of any team. Seattle's position players have been worth just 11.1 Wins Above Replacement this season, fifth-lowest, ahead of only the Pirates, Orioles, Tigers and D-backs. The Mariners would be the only team in the playoffs with a negative run differential, at minus-48.
Rays: Starting pitching
The Rays have a lot of good hitters, and you know how they deploy their stable of bullpen arms. But the starting rotation is unproven, if talented, especially with ace Tyler Glasnow out for the year. Two of Tampa Bay's postseason starters could be rookies, Shane McClanahan and Shane Baz, and a third, Drew Rasmussen, has only been starting since mid-August. And no matter who fills out the rest of the playoff rotation -- Ryan Yarbrough, Michael Wacha, Luis Patiño -- none of them are likely to go deep in a game. The Rays don't have the ace, or aces, of a lot of other playoff teams. Since Glasnow went down, Tampa Bay starters have the highest ERA of any team in postseason position (4.59), and they've thrown the second-fewest innings of any team (419 1/3).
Red Sox: Defense
The Red Sox can hit, that's for sure. But can they prevent enough runs to win? They're the worst fielding team in baseball. Boston's minus-37 Outs Above Average is the worst of any team, which translates to defense costing the team a Major League-high 28 runs. Third baseman Rafael Devers has been the second-worst fielder in the league (minus-14 OAA), and shortstop Xander Bogaerts has been one of the worst at his position (minus-9 OAA), as has first baseman Bobby Dalbec (minus-8 OAA). In a Jackie Bradley Jr.-less outfield, Alex Verdugo has been one of the weakest defensive outfielders in the game, too (minus-7 OAA).
White Sox: Health
The White Sox should have one of the most complete teams in the playoffs. But their injuries have made that a lot more complicated. The biggest question is whether Carlos Rodón, dealing with a sore left arm, will be the X-factor he was for most of the season. Chicago's three other top starters have also all dealt with injuries in September -- Lucas Giolito (left hamstring strain), Lance Lynn (right knee inflammation) and Dylan Cease (right triceps contusion). There's also reliever Evan Marshall trying to work his way back from right forearm soreness, and the revolving door in right field with injuries to Adam Engel (leg tightness) and Brian Goodwin (back tightness). Luckily stars Luis Robert and Eloy Jiménez are back from the injuries that kept them out for a lot of the year.
Yankees: Bringing baserunners home
The Yankees have a lot of home run threats. But when they're trying to push runs across, they've had two big problems: hitting with runners in scoring position and running into outs. With runners in scoring position, the Yankees' .236 batting average this season is fifth-lowest of any team, and their .697 OPS is fourth-lowest, ahead of only the 100-loss Pirates, Orioles and D-backs. With two outs and RISP, their .215 batting average is seventh-lowest, and their .643 OPS is fifth-lowest. Then there's the baserunning. The Yankees are the second-worst baserunning team in baseball this year (minus-15.2 baserunning runs, per FanGraphs, ahead of only the Nationals). They've made 50 outs on the bases, tied for sixth-most, including a league-high 22 outs at the plate.
Braves: Outfield defense
The Braves are making a tradeoff for bats over gloves in the corner outfield. Their deal for Jorge Soler has paid off in power (13 home runs, 125 OPS+), but he's one of the worse defensive outfielders in the league in right (minus-6 Outs Above Average, ranking in the bottom fifth percentile of MLB). In left field, Eddie Rosario has been raking (125 OPS+ with Atlanta), but his defense is average at best. And if the Braves want Joc Pederson's lefty power bat in the lineup, that's another drain on the outfield (minus-5 OAA). Only Adam Duvall has been capable.
Brewers: Power hitting
Home runs win in October … and the Brewers aren't getting very many from some key bats. Christian Yelich has nine homers all season, in 115 games, after averaging 40 a season in his first two years with the team. And trade acquisition Eduardo Escobar, who hit 22 home runs in 98 games with the D-backs, has only six in 45 games with Milwaukee. The Brewers' team slugging percentage is just .397, in the bottom 10 in the Majors and worst among the postseason teams that have clinched a spot. Yelich's .374 slugging is a career low. That's not good from your star hitter.
Cardinals: Too many walks, not enough strikeouts
Strikeouts go up in the playoffs, and it's no accident -- teams use their nastiest pitchers to get the biggest outs. The 2021 St. Louis pitching staff is not a strikeout staff, and has also issued a lot of free passes. The Cards have the third-lowest strikeout rate of any team (20.2%), and the lowest K/9 (7.77). They have the highest walk rate of any team (10.0%), and the third-highest BB/9 (3.85). Put it together, and you get a strikeout-to-walk ratio of just 2.02 that ranks last in the Majors. The Cardinals make up for it by playing elite defense (their +50 Outs Above Average is No. 1 in MLB), but that's still a risky combination.
Dodgers: Center field
It's hard to find a weakness on the Dodgers, but center field might be the closest thing to it. If Cody Bellinger is Cody Bellinger, forget about this. But Bellinger's season has been a nightmare. He's batting .162 -- the very lowest of any player with 300 or more plate appearances this season. His .539 OPS is third-lowest, higher only than Jackie Bradley Jr. and Austin Hedges. He's the third-worst hitter in the league by wRC+. And if Bellinger doesn't play an everyday center field in the postseason, then who? Los Angeles has been playing Gavin Lux, who had zero big league experience in center until a week ago, and has also been a below-average hitter this year. Maybe Chris Taylor is the answer? But he's been slumping through the second half, hitting .188 with a .559 OPS since August.
Giants: First base
This is just bad luck. Brandon Belt was the Giants' unofficial/self-proclaimed team captain, and they just lost him for at least a big chunk of the postseason after he broke his left thumb when he was hit by a pitch this week. Belt was having a huge season -- his 29 home runs were a career high -- and he was red-hot since returning from the injured list on Aug. 5. In fact, he was the fourth-best hitter in baseball over that time (183 wRC+, behind only Juan Soto, Paul Goldschmidt and Bryce Harper). How do you replace that? The Giants will have to try with some combination of Wilmer Flores, LaMonte Wade Jr. and Darin Ruf. None of those players is Brandon Belt.