The best baseball players born on Dec. 23

Who are the best players born on each day of the year? We have a list for every day on the calendar.

Here’s a subjective ranking of the top five for Dec. 23.

1. Jerry Koosman (1942)
Koosman went 222-209 in a 19-year career with the Mets, Twins, White Sox and Phillies, compiling a 53.7 bWAR that is not only tops among players born on this day but also leads all pitchers born in Minnesota (only Hall of Famers Paul Molitor and Dave Winfield and Joe Mauer are ahead of him overall; Hall of Famers Jack Morris and Charles Bender are the pitchers just behind him).

In his rookie year of 1968, Koosman set two Modern Era NL rookie records: most strikeouts by as a batter by a pitcher (62), which he still holds, and most shutouts (seven, broken by Fernando Valenzuela’s eight in 1981). He finished second to Johnny Bench in a close NL Rookie of the Year vote. Pitching for the Mets in the 1969 World Series, Koosman started and won Game 2 (one run in 8 2/3 innings) and the clinching Game 5 (three runs in a complete game). In 2021, the left-hander became the third Mets player to have his number retired.

2. Sam Leever (1871)
A turn-of-the-20th-century right-hander, Leever was a four-time 20-game winner, with his best season coming in the Pirates’ 1903 NL championship season (he went 25-7 with a 2.06 ERA). With his entire career occurring during the Dead Ball Era, Leever went 194-100 with a 2.47 ERA, starting 299 games and completing 241 of them. Leever didn’t make his big league debut until 1898, when he was 26, because after graduating from Goshen High School in Ohio, he taught there for seven years before signing a contract. That earned him the nickname “The Goshen Schoolmaster.”

3. Hanley Ramirez (1983)
The highest-ranked hitter born on this date, Ramirez won the 2006 NL Rookie of the Year Award after batting .292/.353/.480 with 46 doubles, 11 triples, 17 home runs, 59 RBIs and 51 stolen bases for the Marlins. He followed up that season with three top-11 MVP seasons, including 2009, when he finished second to Albert Pujols. Originally a switch-hitter when he signed with the Red Sox at the age of 16, Ramirez gave up batting from the left side in 2005, when he made his MLB debut by getting two September at-bats with Boston. In the offseason, he was the prospect centerpiece of the trade that brought Josh Beckett and Mike Lowell (plus Guillermo Mota) to Boston. Ramirez made three All-Star teams with the Marlins before he was traded to the Dodgers in 2012. His 25 career leadoff homers for the Marlins from 2006-12 are still the franchise record.

4. Victor Martinez (1978)
A switch-hitting catcher-turned-DH with a strong batting eye, Martinez made five All-Star teams and won two Silver Slugger Awards in a 16-year career. At the age of 35 in 2014, he finished second to Mike Trout in AL MVP voting by hitting .335/.409/.565 with an MLB-best .974 OPS. He hit 32 home runs and drove in 103 runs and walked nearly twice as much as he struck out (70 to 42). His 103 home runs with Cleveland are the most by a catcher in franchise history, 11 more than Sandy Alomar Jr.

5. Mitch Haniger (1990)
A supplemental first-round pick (No. 38 overall) by the Brewers in 2012, Haniger was dealt to the D-backs in 2014 and made his MLB debut two years later. Following the 2016 season, he was traded again, along with Zac Curtis and Jean Segura, to the Mariners for Ketel Marte and Taijuan Walker. A good hitter when healthy, Haniger has had some bad injury luck, missing significant time in 2017 and ’19 and all of the truncated 2020 season. But in 2018 and ’21, he played in 157 games each time, averaging 32 home runs and 96 RBIs and making the AL All-Star team in ’18 and receiving MVP votes each time. After five seasons with the Mariners, Haniger joined the Giants in 2023, then returned to the Mariners in a trade in '24.

Others of note:

Tommy Thomas (1899)
A right-handed pitcher out of Baltimore, Alphonse “Tommy” Thomas made his professional debut with the Triple-A Buffalo Bisons in May 1918 while still in high school. He pitched the third game of the season in his hometown as a sort of tryout, defeating the Orioles and earning a full contract with Buffalo, though he wouldn’t join the team until the school year was over. Waived by the Bisons in 1921, Thomas was claimed by the Orioles and went 24-10 for the 119-win club, one of the best in Minor League history (Hall of Famer Lefty Grove went 25-10 for that team). Baltimore sold Thomas’ contract to the White Sox in 1925, and he went 15-12 as a rookie in ’26, second on the team in wins behind Hall of Famer Ted Lyons (18-16). In a 12-year career with the White Sox, Senators, Phillies, Browns and Red Sox, Thomas went 117-128 with a 4.11 ERA and 25.3 bWAR.

Brad Lidge (1976)
The 17th overall pick by the Astros in 1998, Lidge is tied with outfielder AJ Pollock as the highest-drafted players out of the University of Notre Dame. Known in part for giving up Albert Pujols’ go-ahead home run in Game 5 of the 2005 NLCS, Lidge nonetheless saved 123 games in six seasons in Houston, leaving him third in franchise history behind Billy Wagner and Dave Smith. Traded to the Phillies before the 2008 season, Lidge saved 41 games in 41 chances in the regular season, then added seven more without a blown save in the postseason. He closed out each of Philadelphia’s clinching games that October, including the World Series victory over Tampa Bay. Lidge’s 18 postseason saves ranked second all-time at the end of his career, second to Mariano Rivera’s 42. Kenley Jansen tied Lidge in 2020 and passed him in ’21.

Jerry Manuel (1953)
Primarily a second baseman in his five-year career, Manuel played only 96 games with a lifetime OPS of .498. Named the manager of the White Sox in 1998, he led the team to four second-place finishes and one AL Central title (2000) in six seasons at the helm, going 500-471-2 from ’98 to 2003. He joined manager Willie Randolph’s Mets staff in 2005, becoming bench coach in ’06. When Randolph was fired in June 2008 after starting out 34-35, Manuel led a turnaround, guiding the Mets to a 55-38 mark the rest of the way. That finish earned him a two-year deal, but after the Mets won 70 and 79 games in those seasons, Manuel’s contract option was not picked up, and he hasn’t managed since.

Want to see more baseball birthdays for Dec. 23? Find the complete list on Baseball Reference.