With the postseason set to begin Tuesday, it’s time to take stock of which players led Major League Baseball, or their respective leagues, in notable statistical categories for the 2019 regular season -- from traditional stats to Statcast metrics.

Here's a look at the leaders in each category this season:

BATTING
Home runs

NL/MLB -- Pete Alonso (NYM): 53
No rookie had ever led his league in home runs outright before 2019. Enter Alonso. The Polar Bear did it all in the home run department in 2019, setting the Mets’ single-season franchise mark, as well as the all-time rookie record. He’s also the first Mets player to take home the Major League home run title. Entering 2019, the Mets were one of nine teams to never have a player lead the Majors in home runs.

AL -- Jorge Soler (KC): 48
Soler’s impressive campaign is the first 40-homer season in Royals history, but that’s not all. Soler became the first Kansas City player to claim the home run title, while his 48 homers are also the most by any Cuban-born player in Major League history.

Batting average

AL/MLB -- Tim Anderson (CWS): .335
Anderson hit .381 in September en route to leading the Majors in batting average. He’s the first White Sox player to win a batting title since Frank Thomas in 1997 and the second White Sox player to lead the Majors in hitting, joining Luke Appling in '36. Anderson’s 15 walks are the fewest by any player to win a batting title, just edging out Zack Wheat, who walked 16 times in '18.

NL -- Christian Yelich (MIL): .329
Last year, Yelich became the first player in Brewers history to win a batting title. Now, he’s notched it two years in a row, as he had already racked up enough plate appearances to qualify when he broke his right kneecap. Ketel Marte also hit .329, but his mark was lower than Yelich's when rounding to a third decimal place (Yelich .3292 compared to Marte's .3286). Yelich is the first NL player to win back-to-back batting titles since Larry Walker in 1998-99.

RBIs

NL/MLB -- Anthony Rendon (WSH): 126
In the Nationals’ first year without Bryce Harper, Rendon helped pave the way to a postseason appearance for Washington. He’s the first Nats player to lead the NL in RBIs since the team moved to Washington in 2005, and first for the franchise overall since Expos catcher Gary Carter shared the NL lead with Mike Schmidt in 1984. Rendon is the first-ever player from the franchise to lead the Majors in RBIs.

AL -- José Abreu (CWS): 123
Abreu is just the second White Sox player to lead the AL in RBIs, joining Dick Allen in 1972. It’s Abreu’s fifth 100-RBI season in his first six Major League seasons. He’s one of just 13 players with at least five 100-RBI seasons within his first six seasons, and one of just two White Sox players to do so, joiningThomas.

Stolen bases

AL/MLB -- Mallex Smith (SEA): 46
Smith has racked up consecutive 40-steal seasons, with his 46 this season representing a career high. He’s the third Mariners player to lead the AL in the category, joining Ichiro Suzuki in 2001 and Harold Reynolds in 1987. Ichiro is the only other Seattle player to lead the Majors overall.

NL -- Ronald Acuña Jr. (ATL): 37
Acuña’s bid for a 40-40 season fell short when he sustained a groin injury Tuesday that ended his season prematurely, but he still racked up 37 stolen bases. He’s the first Braves player to lead the NL in the stat since Bill Bruton in 1955, when the team was in Milwaukee.

On-base percentage

AL/MLB -- Mike Trout (LAA): .438
This is nothing new for Trout, who has led the AL in on-base percentage for four straight seasons. He’s the first player to lead his league in OBP in four straight seasons since Joey Votto from 2010-13, and the first in the AL since Wade Boggs did so in five straight from 1985-89.

NL -- Christian Yelich (MIL): .429
Yelich’s first time leading the league in on-base percentage snaps Votto's streak of three straight years leading the NL. As with his batting title last year, Yelich is the first Brewers player to lead the league in on-base percentage.

Slugging percentage

NL/MLB -- Christian Yelich (MIL): .671
This is Yelich’s second straight year leading the NL in slugging, and his first year leading the Majors. The only other Brewers player to lead the Majors in slugging was Robin Yount in 1982, when he led the AL -- before the Brewers moved over to the Senior Circuit. Yelich’s .671 slugging percentage is the highest in a single season in franchise history. It’s also the highest by any player in a qualified season since Albert Pujols slugged .671 in 2006 for the Cardinals.

AL -- Mike Trout (LAA): .645
Trout’s .645 slugging percentage was the highest of his career. It’s the third time he’s led the AL in slugging, also doing so in 2017 and '15. The only other Angels player to lead the AL in slugging was Bobby Grich in 1981. Trout’s .645 slugging percentage was the highest by an AL player in a qualified season since Alex Rodriguez slugged .645 in 2007, en route to winning the Most Valuable Player Award.

Statcast barrels

AL/MLB -- Jorge Soler (KC): 70
Soler’s high-powered season can be encapsulated by his leading the Majors in barrels, which are batted balls with the ideal combination of launch angle and exit velocity, typically resulting in extra-base hits. Since Statcast began tracking in 2015, no Royals player had ever had more than 48 in a season (Kendrys Morales in 2016). Soler’s campaign is one of nine 70-barrel seasons since 2015.

NL -- Pete Alonso (NYM) / Ronald Acuña Jr. (ATL): 66

Alonso and Acuña each posted seasons with the most barrels by any player from their respective teams since the stat has been tracked by Statcast. Forty-eight of Alonso’s 53 home runs were barreled, just five shy of the most barreled homers in a year -- 53 by Giancarlo Stanton in 2017.

PITCHING

Wins

AL/MLB -- Justin Verlander (HOU): 21
Verlander became a 20-game winner for the first time since 2011, the season he won both the AL Cy Young and MVP Awards with the Tigers. In his final start of the season, not only did he lock up the MLB wins title with No. 21, he also reached a pair of milestones: 3,000 career strikeouts and 300 strikeouts for the season.

NL -- Stephen Strasburg (WSH): 18
The Nationals' starting trio of Strasburg, Max Scherzer and Patrick Corbin was a big reason why they made it back to the postseason. Strasburg had a career year in several categories, setting personal bests in wins, innings pitched (209) and strikeouts (251).

ERA

NL/MLB -- Hyun-Jin Ryu (LAD): 2.32
It was Ryu, not either of his fellow star Dodgers pitchers in Clayton Kershaw or Walker Buehler, who won the 2019 ERA title. Ryu's amazing All-Star season included an MLB-high 10 starts in which he went at least seven innings without allowing an earned run.

AL -- Gerrit Cole (HOU): 2.50
Cole and Verlander made the AL Cy Young competition a two-ace race. The Houston teammates dominated all year long, with each leading the league in different categories. The AL ERA title goes to Cole, who finished at 2.50 to Verlander's 2.58.

Strikeouts

AL/MLB -- Gerrit Cole (HOU): 326
Like ERA, strikeouts go to Cole. He and Verlander both reached the 300-strikeout mark, becoming just the second pair of teammates to do so in MLB history (Randy Johnson and Curt Schilling for the 2002 D-backs). But Cole finished 26 strikeouts ahead of Verlander's even 300, including an MLB-high 21 games with double-digit whiffs. Cole closed the regular season with an MLB record nine consecutive 10-strikeout performances.

NL -- Jacob deGrom (NYM): 255
deGrom finished strong in his quest for a second straight NL Cy Young Award. He led the league in strikeouts for the first time and reached the 250-K mark for a second consecutive season, to go along with his 2.43 ERA (second in the NL) and 204 innings pitched (third in NL).

Saves

NL/MLB -- Kirby Yates (SD): 41
Entering 2019, Yates had 14 saves in 21 career opportunities. This season, however, he went 41-for-44 in save chances, leading the Majors. He’s the first Padres pitcher to lead the NL in saves since Heath Bell in 2009, and the first to lead the Majors in saves since Hall of Famer Trevor Hoffman in 1998.

AL -- Roberto Osuna (HOU): 38
In his first full season with the Astros after heading to Houston in a July deal in 2018, Osuna went 38-for-44 in save chances, racking up his second-most saves in any season of his career. He’s the first Astros pitcher to lead the league in saves since José Valverde in 2008, when the Astros were in the NL.

FIELDING

Outs Above Average (outfielders)

NL/MLB -- Victor Robles (WSH): +21
Statcast's Outs Above Average is pretty straightforward -- it takes the catch probability of every ball hit to an outfielder, then credits them for the plays they make and debits them for the ones they miss. No one was better this season than Robles, who was seven OAA above the next-closest NL outfielder (Milwaukee's Lorenzo Cain).

AL -- Kevin Kiermaier (TB): +17
Kiermaier covers tons of ground in center field, and his OAA total shows it. One of the keys to his range? Kiermaier gets the best jumps of any MLB outfielder.