The stretch run of the season is about more than just postseason races. It's also milestone watch time.
This year, there are plenty of marks being chased around baseball -- single-season records for today's biggest stars and career plateaus for some generational greats.
Here are 11 major milestones to look for the rest of the 2019 season.
Christian Yelich: First 50-30 player in history
No one in Major League history has ever hit 50 homers and stolen 30 bases in a season. So for Yelich to even have a chance speaks to the incredible year he's having. He's got an MLB-best 39 homers and 23 steals right now, so he needs 11 and seven in the Brewers' final 43 games. Not easy, but not impossible. And with Yeli looking ready to return to the Brewers lineup Tuesday, he's still on a 53-homer, 31-steal pace.
Ronald Acuna Jr.: 40-40 club
Likelihood: Within reach
Acuna enters Tuesday's series opener against the Mets with 33 home runs and a National League-leading 28 stolen bases. He could join the 30-30 club any day now, and at 21 he'll be the second-youngest member, behind only Mike Trout (30-49 in his age-20 season in 2012). But Acuna has a chance for more. He has a real shot at 40-40.
With 42 games left to play, Acuna needs seven more homers and 12 more steals. Just since the All-Star break, he's hit 12 homers and stolen 15 bases in 29 games. If he stays hot, he could become just the fifth, and the youngest, 40-40 club member. The only four players with 40 homers and steals in a season are Alfonso Soriano (46-41 in 2006), Alex Rodriguez (42-46 in 1998), Barry Bonds (42-40 in '96) and Jose Canseco (42-40 in '88). Acuna would be even younger than A-Rod, who did it at age 22.
The Braves phenom has himself on a pace for about 45 homers and 38 steals. So 40-40 looks within the realm of possibility. It will be fun to watch Acuna chase it.
Justin Verlander: 3,000 career strikeouts
Likelihood: Has a chance
Verlander entered the season with 2,706 strikeouts, meaning he'd need to collect a career-high 294 this season to join the Hall of Fame-caliber 3,000-strikeout club. We're now in August, and the Astros' ace has a real shot to get there.
Verlander currently sits at 217 strikeouts for the season and 2,923 in his career. He needs 77 in the Astros' final 42 games -- a span in which he could make about eight more starts if he pitches every fifth day. So he's looking at around 10 strikeouts per start, or close to it, if he's going to get 3,000 in 2019. Well … he's had double-digit K's five games in a row now. If anyone can do it, it's him.
Pete Alonso: NL/MLB rookie HR records
Likelihood: Very likely (NL); Longshot (MLB)
Alonso's only one home run away from tying the NL rookie home run record (Cody Bellinger's 39 in 2017); he should smash through that one. The MLB rookie home run record would take a big power surge. Aaron Judge holds that mark, with the 52 he hit in that same '17 season. Polar Bear Pete would need to crush 15 homers in the Mets' final 44 games to surpass Judge.
Mike Trout: Most WAR through age 28
If the season ended today, Trout would already have amassed the highest Wins Above Replacement total by age 28 for any position player in MLB history. The Angels superstar passed Ty Cobb's record of 69.0 WAR earlier this season, and has 71.8 WAR to date, per Baseball-Reference.com. Trout might well be looking at his fourth career 10 WAR season -- a mark only Babe Ruth, Willie Mays and Rogers Hornsby have hit more than three times.
Now, the fun question is to see which other all-time greats Trout passes in career WAR before the year is out. A 10-WAR season would put Trout at just above 74 WAR for his career. Along the way, he'd pass players like Derek Jeter (72.4), Larry Walker (72.7), Jim Thome (72.9), Frank Thomas (73.9) and Reggie Jackson (74.0). Even if Trout doesn't get to 10, he could still eclipse some of those iconic names this season.
DJ LeMahieu/Fernando Tatis Jr.: Batting title history
Likelihood: Within reach
LeMahieu is hitting .338 to lead the AL batting race (and the MLB batting race) in his first season with the Yankees. He's already won one batting title, in the NL with the Rockies in 2016. If he wins two, he'll make history: No player in the modern era has ever won a batting title in both leagues.
Tatis has a chance for history too. He just qualified for the batting race leaderboard and is hitting .315 through Monday's games. He's 20 points behind Yelich atop the league, but Tatis is within striking distance, and his numbers have more room to jump, since he has logged fewer at-bats. The Padres' electric rookie will be 20 years, 270 days old when the season ends; he'd be 10 days younger than Al Kaline was when he won the American League batting title for the Tigers in 1955.
No NL rookie has ever won a batting title. Tatis could do it. So could the Pirates' Bryan Reynolds, who sits just two points off the league lead at .333. Watch him, too.
Hyun-Jin Ryu: Lowest ERA since the mound was lowered
Likelihood: Fairly low
Ryu has a 1.45 ERA through 22 starts and 142 2/3 innings. He's allowed zero or one earned run in 15 of his past 17 outings. With each passing start, he draws closer to historic territory. Ryu could have the lowest ERA by any qualified starter since MLB lowered the mound in 1969. That mark belongs to Dwight Gooden, who posted a 1.53 ERA for the 1985 Mets.
Yes, Ryu's ERA right now is even lower than '85 Doc's. It's under the 1.50 threshold that only one pitcher in the live-ball era has ever broken -- Bob Gibson in his legendary 1968 season, the 1.12 ERA season that prompted the mound's lowering.
It will be hard for Ryu to keep this up the rest of the way -- remember how dominant Jacob deGrom was last year, and he finished with a 1.70 ERA; or how dominant Dodgers like Clayton Kershaw and Zack Greinke were when they finished with ERAs of 1.77 in 2014 (Kershaw) and 1.66 in '15 (Greinke). But it's been a magical season. Maybe Ryu can do it.
Albert Pujols: Top 5 on the HR list, Top 15 on the hits list
Likelihood: Longshot (HR); High (hits)
Pujols isn't the superstar he once was, but the 37-year-old is still slugging homers, and the highest reaches of the all-time list is coming into view. Pujols (651) is nine home runs away from tying Willie Mays (660) and moving into the Top 5 in MLB history. He might not get there until next year, but one good run of long balls and he could find himself within reach of the Say Hey Kid in the final month of 2019.
As far as hits, Pujols has already cracked the biggest milestone -- 3,000 -- to enter baseball's most famous club. Now he's just marching up the all-time leaderboard. At 3,165 career hits, he's about to pass Adrian Beltre (3,166) and seems likely to pass Iron Man Cal Ripken (3,184) to crack the Top 15 before the season is out.
Gerrit Cole/Chris Sale/Max Scherzer: Historic K rates
Here's the list of qualified pitchers with a single-season strikeout rate higher than Cole's current 36.8 percent: Pedro Martinez (37.5 percent in 1999) and Randy Johnson (37.4 percent in 2001). Those are two of the greatest pitchers of all time at the peak of their Hall of Fame careers. Cole is right there with them. Sale and the sidelined-for-now Scherzer aren't far behind; they're both at 35.3 percent. Cole, Sale and Scherzer would have to keep striking out the world to challenge Pedro and Randy, but they've more than shown they can do just that.
All three pitchers could hit other milestones along the way, too. Cole is going to push for a 300-strikeout season (he has an MLB-leading 226 right now). Sale is about to eclipse 2,000 career strikeouts (he's at 1,995). And Scherzer could lead the NL in strikeouts for a fifth straight season, even with the time he's missing.
Twins/Orioles: Single-season team HR records
Likelihood: Very high
The Twins have 228 home runs through 118 games. The single-season team home run record, set by the Yankees last year, is 267. The Twins look like they'll slug their way past that with room to spare. Heck, the Yankees, who have 214 homers in 119 games, will probably smash their own record, too -- the Twins are just even further ahead of their pace.
The Orioles, meanwhile, just set the AL record for most home runs allowed in a season -- they're at 248 now, and the MLB record is just 11 long balls away (the 2016 Reds allowed 258).
Trout, Yelich, Bellinger, Alonso, Jorge Soler: Franchise HR marks
Likelihood: All on pace
• Trout (39) is on pace for 53 home runs. The Angels' single-season record is 47 (Troy Glaus, 2000).
• Yelich (39) is also on pace for 53. The Brewers' record is 50 (Prince Fielder, 2007).
• Bellinger (38) is on pace for 51. The Dodgers' record is 49 (Shawn Green, 2001).
• Alonso (38) is on pace for 52. The Mets' record is 41 (Carlos Beltran, 2006; Todd Hundley, 1996).
• Soler (35) is already within three of the Royals' record (38 by Mike Moustakas in 2017). He should surpass that with ease.
They probably won't all set new single-season franchise records, but Soler and Alonso almost certainly will, and the other three have a good shot.
David Adler is a reporter for MLB.com based in New York. Follow him on Twitter at @_dadler.