Bartolo Colon turned 45 today.At an age when most successful players have been retired long enough to be eligible for the Hall of Fame, Colon is still going strong. In 10 games (eight starts) for the Rangers this season, the right-hander has a 3.51 ERA despite allowing six runs in

Bartolo Colon turned 45 today.

At an age when most successful players have been retired long enough to be eligible for the Hall of Fame, Colon is still going strong. In 10 games (eight starts) for the Rangers this season, the right-hander has a 3.51 ERA despite allowing six runs in 5 1/3 innings against the powerful Yankees on Monday night.

In celebration of Bart's birthday, and in his 21st MLB season, here are 21 amazing facts about a pitcher who continues to defy the aging curve:

1. With Ichiro Suzuki no longer active for the Mariners, Colon (born May 24, 1973) is one of just two players 40 or older on an MLB roster, and he is nearly four years older than 41-year-old Twins reliever Fernando Rodney (born March 18, 1977). Colon and Adrian Beltre (who turned 39 in April) are the only two active players who appeared in a game in the 1990s.

2. Colon is the first player since 2012 to play in his age-45 season. That year, Omar Vizquel suited up for the Blue Jays at 45 and Jamie Moyer for the Rockies at 49. Colon is only the sixth player to do it since 1995, also joining Randy Johnson, Julio Franco and Jesse Orosco.

3. The youngest player to appear in the Majors so far is recent Nationals callup Juan Soto, who was born on Oct. 25, 1998. By that point, Colon already had pitched two seasons in the Majors, starting 48 games for the Indians (plus two in the postseason) and making an American League All-Star team.

4. When Colon made his Major League debut on April 4, 1997, starting for the Indians in Anaheim, there were only 28 MLB teams (no D-backs or Rays). The Tigers were in the AL East, the Brewers in the AL Central, the Astros in the National League Central, and the Nationals had a different name and home city. The players had been on strike only a few years before, and the reigning AL and NL MVP Award winners were Juan Gonzalez and Ken Caminiti, respectively.

5. In that debut, Colon allowed a hit to his first batter, Darin Erstad, and recorded his first out by striking out Jim Edmonds. He also faced Eddie Murray, who was born on Feb. 24, 1956. In his most recent start, on Monday, Colon faced the Yankees' Gleyber Torres , who was born nearly 41 years later, on Dec. 13, 1996.

6. Colon has been around long enough that one of his 11 teams hasn't existed for 14 years. That, of course, was the Montreal Expos, for whom he pitched 17 games in 2002. The franchise moved to Washington and became the Nationals for the '05 season, and Colon is the last remaining active player to have been an Expo.

7. The Rookie of the Year Award winners for Colon's rookie season (1997) were Nomar Garciaparra (AL) and Scott Rolen (NL), who last played in 2009 and '12, respectively. In fact, of the 18 players to win that award from 1997-2005, only Ichiro and Jose Pujols have played in the Majors this year, with only Pujols also remaining active.

8. Colon was already 32 years old during his 2005 AL Cy Young Award-winning season with the Angels. Yet of the 12 other pitchers who received Cy Young Award votes that year, in either league, none remains active. In fact, none has been active since 2015, when Mark Buehrle pitched his final season.

9. Colon is older than six MLB managers: the Mets' Mickey Callaway, the Rays' Kevin Cash, the Red Sox's Alex Cora, the Padres' Andy Green, the Astros' AJ Hinch and the Phillies' Gabe Kapler. Two more -- the Yankees' Aaron Boone and the Dodgers' Dave Roberts -- are older than Colon by less than a year. To pick out just one example, consider the case of Green. Now in his third season as a skipper, Green was drafted by the D-backs (a team that had yet to play a game when Colon debuted) and didn't make the Majors as a player until June 12, 2004 -- the same day Colon was making his 224th big league start.

10. Boone, Cora, Hinch, Kapler and Roberts all batted against Colon during their playing careers. Other current managers who faced Colon: the Brewers' Craig Counsell, the Nationals' Dave Martinez, the Cardinals' Mike Matheny and the Twins' Paul Molitor.

11. Colon is also older than his current boss, Rangers president of baseball operations and general manager Jon Daniels, who is 40.

12. There are 18 Hall of Famers who stepped to the plate against Colon during their careers. Frank Thomas did it the most (38 plate appearances) and made Colon miserable, going 14-for-29 (.483) with two home runs and a 1.433 OPS.

13. If not Thomas, then Colon's toughest opponent has been Alex Rodriguez, whose eight home runs off Colon are two more than any other player. A-Rod torched Colon for a .411/.429/1.000 batting line and 20 RBIs over 63 plate appearances between 1997-2012. In '05, when Rodriguez won the AL MVP Award with the Yankees and Colon took home the AL Cy Young Award with the Angels, Rodriguez homered in each of his first four trips to the plate against Colon -- in all three of their matchups on April 26, and then their first on July 21.

14. On the other hand, Colon dominated David Ortiz. He held Big Papi to a .154/.228/.250 line across 57 plate appearances from 1997-2015, allowing just one home run and two RBIs, while striking him out 15 times -- tied for his most against any opponent.

15. Ichiro has been Colon's most common foe, with the two facing off 118 times -- or 38 more than the next closest, Beltre. Ichiro batted .299/.305/.419 against Colon, with three home runs, walking only once and striking out eight times.

16. Colon has faced all 30 teams, making his most starts against the Mariners (39) and his fewest against the D-backs and Rockies (five apiece). He has at least one win against all 30 as well, and his 21 victories against his current club (the Rangers) are tied with the Mariners for his most against anyone.

17. Colon has pitched in 45 big league ballparks, including all 30 active parks and many defunct ones -- including Tiger Stadium and the Astrodome -- plus the Tokyo Dome during a season-opening series for the A's in 2012. His 88 games at Progressive Field still rank as his most at any stadium, even though he has pitched there just four times in the past 15 seasons. Colon's favorite visiting park has to be Seattle's Safeco Field, where he has gone 14-1 with a 1.98 ERA in 16 starts between 1999 and this season, when he tossed 7 2/3 scoreless innings there on May 16.

18. Colon has played with 669 teammates in his career, with his longest-tenured teammate being Hall of Famer Jim Thome (seven seasons).

19. Colon was an AL Cy Young Award winner with the Angels in 2005, but how many degrees of separation does he have from Hall of Famer Cy Young? According to Baseball-Reference.com, only six. Young, who pitched from 1890-1911, played with Hank Gowdy on the '11 Boston Rustlers (later Braves); Gowdy played with Johnny Cooney on the '30 Boston Braves; Cooney played with Warren Spahn on the '42 Braves; Spahn played with Phil Niekro on the '64 Milwaukee Braves; Niekro played with Tom Candiotti on the '86 Indians; and finally, Candiotti and Colon were Cleveland teammates in '99.

20. Colon made his professional debut in 1994 with the Burlington Indians of the Rookie-level Appalachian League, a year after signing with the Indians as an amateur free agent out of the Dominican Republic. In other words, it's now been about 24 years since Colon first suited up for an MLB organization. To put that in context, we're now nearly as far from Colon's pro debut as that event was from 1969, when the Royals, Padres, Brewers (then the Seattle Pilots) and Expos played their first games, and the postseason expanded to include the first AL and NL League Championship Series.

21. Colon's next start will be his 153rd since turning 40, tying Gaylord Perry for ninth most all time. Should he remain in the rotation all season, Colon could pass Perry, Spahn (155), Tommy John (157), Randy Johnson (162) and Jack Quinn (169) for fifth place. Niekro (294) is the all-time leader, and Colon would need to pitch another four full seasons after this one to catch him. That seems unlikely, but if recent years have taught us anything, it's this: Don't count out Bartolo Colon.