Who are the most crucial players down the stretch for contenders? I'm not necessarily asking which players are the best, but which players will have the greatest impact on which teams wind up playing baseball in October and which ones go on vacation to catch up on some early autumn golf.
To get an idea, using the ZiPS projections for the rest of the season, I projected the 2019 stretch run a million times and in each of these simulations, replaced the best players in baseball with what replacements their teams have available. And with baseball's trade deadline now more strictly a July 31-or-bust proposition without the August waiver period, most team's Plan B options are going to have to come in-house.
So for these players on these contenders, it's now or never.
Christian Yelich, OF, Milwaukee Brewers
If the season ended today, Christian Yelich vs. Cody Bellinger would be one of the most difficult MVP votes I can remember and I'd pity the writers who have to decide who to snub. But in terms of which one will affect the playoff hunt the rest of the way, there's no question that Yelich has the ability to shape the fate of his team far more than Bellinger. With a lead approaching 20 games in the NL West and an eight-game lead for the NL's best team, the Dodgers could replace Bellinger with his dad, 50-year-old former Yankee utility guy Clay, and still not change the outcome of their season.
Over the last calendar year, Yelich has hit .345/.440/.745 with 58 homers and 138 RBIs. Milwaukee's offense isn't the big powerhouse that some believe it to be -- they're eighth in the NL in runs scored -- and Yelich carries an unbelievable load. Without Yelich performing at a peak level, the Brewers won't have much on tap to offer in October.
Francisco Lindor, SS, Cleveland Indians
After not making the barest effort to sign Michael Brantley or doing much of anything to replace his lost offense from an outfield that was below average with Brantley, Cleveland came into the season extremely reliant on getting offense from Francisco Lindor and Jose Ramirez. J-Ram seems to have gotten back on track, but Lindor has had to carry an unbelievable load, and even with offensive upgrades to the rest of the lineup in the form of Yasiel Puig and Franmil Reyes, Lindor is still the team's single most valuable source of offense.
Max Scherzer, starting pitcher, Washington Nationals
The Nationals are currently at the top of the pack of National League wild-card contenders, but half the league is only a few games off the pace. So as cliché-ridden as the "every game counts" stuff can be, there's a real mathematical basis for thinking the Nats are playing in an unbelievably high-leverage environment for the next six weeks. Sure, the team has survived Scherzer's injury so far, but it's not something they want to be testing out over their remaining 39 games.
Matt Chapman, 3B, Oakland Athletics
No, Matt Chapman's 2018 was not a fluke. Like the rest of the league, Chapman has added even more power in 2019, but more importantly he has retained his Gold Glove contender status. In WAR, Chapman is tied with Anthony Rendon for third in baseball at third base and the A's would be hard-pressed to replace his production with some combination/shifting around of Jurickson Profar, Chad Pinder and Corban Joseph.
Shane Bieber, starting pitcher, Cleveland Indians
At 12-5 with a 3.27 ERA while ranking sixth in baseball in WAR among pitchers, Bieber has been one of the most surprising pitchers in baseball -- though not so much to ZiPS which had him 13th in MLB coming into the season, a projection I was worried about. With the health status of Carlos Carrasco and Corey Kluber up in the air and Trevor Bauer in Cincinnati, Bieber is the pitcher the team is most counting on. In a tight race with the Twins, he's the pitcher they can't afford to lose.
Juan Soto, OF, Washington Nationals
Soto has built upon his shocking age-19 season into his age-20 campaign with an almost identical OPS+, adding a 138 so far to his rookie season's 142. Ronald Acuña Jr. has the edge as an overall player among the young NL East phenom outfielders, but Soto is the one playing in the tighter playoff race. In an emergency, the Nats likely would have to replace Soto with some combo of Howie Kendrick and Gerardo Parra and there's little on the farm to take the place of the latter.
Bryce Harper, OF, Philadelphia Phillies
The Phillies have failed to score runs for most of the season and currently rank ninth in the NL in runs scored, despite playing in a slight hitter's park. The team has already lost Andrew McCutchen for the season and Jay Bruce has only been healthy enough to get into a single game since mid-July. The team's paper-thin offensive depth has already forced it to start Adam Haseley. Losing their $300 million man, the Phillies would have to dip into their grab bag of role players you might not be aware are actually on the team unless you've been paying attention: Brad Miller, Logan Morrison and Sean Rodriguez. Even if he's not playing like MVP-level Harper, All-Star Harper is just as urgently needed in Philadelphia.
Jacob deGrom/Noah Syndergaard, starting pitchers, New York Mets
OK, this is kind of a top-11 list, but deGrom and Syndergaard come up right in order for identical reasons: excellent pitchers on a team without a great deal of rotation depth. I never thought I'd bemoan the loss of Jason Vargas, but if the Mets lose a starting pitcher down the stretch, they'd likely resort to using Ervin Santana, Chris Mazza or Walker Lockett, all of whom are obvious downgrades. Seth Lugo remains a theoretical possibility, but the bullpen can't exactly afford to shed one of its most valuable arms either. However far the Mets go, it will depend on this duo down the stretch to get them there.
Kris Bryant, 3B, Chicago Cubs
Now that Yu Darvish has decided to no longer walk batters ever and pitch like the limited-edition gold foil version of Yu, Kris Bryant is the player the Cubs can least afford to lose now that he has mostly re-discovered his missing power. Nicholas Castellano has been white-hot these last couple of weeks, but Bryant is the still the Cub to bet on.
Charlie Morton, starting pitcher, Tampa Bay Rays
The current AL leader in ERA, at least as of Monday morning, isn't Justin Verlander or Gerrit Cole or Wade Miley, but an ex-Astro, Tampa Bay's Charlie Morton, whose two-year, $30 million contract is looking like highway robbery on the Rays' part. At 5.2 WAR (FanGraphs blend), Morton has a chance to double-up on his previous career best of 3.1 from 2017 and is a realistic Cy Young contender. Morton has certainly had one of the more interesting career paths, going from a mediocre oft-injured pitcher with a middling fastball in his 20s to being able to touch the high-90s in his 30s. He doesn't turn 36 until November, so there's still time for him to suddenly learn to pitch left-handed, too.
The Rays have shown a lot of creativity with their pitching staff, but the openers and bullpen games only work if they can squeeze out enough innings from the starting pitching in the "other" games. Without Charlie Morton, it would be a lot harder to hold off Oakland.