Here comes Julio Urias! Nineteen things to know about teenage pitchers

Julio Urías has some striking similarities to Fernando Valenzuela (0:30)

Julio Urías draws comparisons to Dodgers legend Fernando Valenzuela, whose start to 1981 season spawned "Fernandomania." (0:30)

When 19-year-old left-hander Julio Urias starts Friday night for the Los Angeles Dodgers, the baseball world will tune in to one of the most exciting debuts we'll see this season. Urias is regarded as the second-best pitching prospect in the game behind Lucas Giolito of the Nationals, and has dominated at Triple-A Oklahoma City. He enters Friday's start against the Mets riding a 27-inning scoreless streak while posting a season ERA of 1.10 with 24 hits and 44 strikeouts in 41 innings. Given his age, the Dodgers have him on a strict innings limit and he's yet to top 82 pitches in a game, so don't expect him to go too deep into this start.

The Dodgers first scouted Urias in Mexico when he was 15, and he was so polished they started him in Class A ball in 2014 when he was still just 16. That early precociousness means he will be the first teenager to start in the majors since Felix Hernandez of the Mariners, who made 12 starts as a teenager in 2005. With that in mind, I thought it would be fun to look into the history of teenagers pitching in the majors. With help from indispensable Baseball-Reference Play Index, here are 19 things to know about teenage pitchers:

1. Urias will be just the fourth teenage pitcher in the past 25 years:

2. Hernandez made his debut in August 2005, allowing two runs in five innings against the Tigers and taking the loss. But in his second start he pitched eight scoreless innings, and in his third he struck out 11 in eight innings and allowed just one run. That made him the first teenager since Dwight Gooden in 1984 to strike out 10 or more in a game. Gooden did that an amazing 15 times that season, all while 19 years old.

3. Most strikeouts in a game by a teenager:

1. Bob Feller, Oct. 2, 1938: 18 (19 years, 333 days)

2. Feller, Sept. 13, 1936: 17 (17 years, 315 days)

3. Feller, Aug. 25, 1937: 16 (18 years, 295 days)

3. Dwight Gooden, Sept. 12, 1984: 16 (19 years, 301 days)

3. Gooden, Sept. 17, 1984: 16 (19 years, 306 days)

6. Feller, Aug. 23, 1936: 15 (17 years, 294 days)

6. Gary Nolan, June 7, 1967: 15 (19 years 11 days)

4. That's not a misprint: Feller was 17 when he debuted with Cleveland. That fall, he would go back to Iowa to finish up his senior year of high school, and Time magazine put him on its cover the following April. He flew home in May to attend his graduation.

5. You will note that Gooden fanned 16 in consecutive games. How impressive is that? He's the only pitcher of any age to do that. Only Pedro Martinez (who did it three times) and Roger Clemens managed to do even 15 in consecutive games.

6. Not surprisingly, Gooden holds the season mark for strikeouts by a teenager, with 276 in 1984, a total that led the majors. At the time, Gooden set a major league record averaging 11.4 K's per nine innings.

7. Gooden's season does not, however, rank as the best ever by a teenager, at least by WAR. That honor belongs to Nolan, who starred for the Cincinnati Reds in 1967. The comparison:

Nolan: 14-8, 2.58 ERA, 226.2 IP, 5 SHO, 62 BB, 206 SO, 18 HR

Gooden: 17-9, 2.60 ERA, 218 IP, 3 SHO, 73 BB, 276 SO, 7 HR

Nolan rates better primarily because of park effects, I guess. He hurt his shoulder in spring training the following season and battled arm injuries the rest of his career.

8. Sandy Koufax and Don Drysdale both debuted as teenagers with the Brooklyn Dodgers. Koufax was 19 in 1955, when he posted a 3.02 ERA in 41.2 innings. Drysdale came up the next season and had a 2.64 ERA in 99 innings.

9. We actually have pitch counts for those two, as a Dodgers statistician named Allan Roth kept track. Drysdale topped out at 126 pitches and Koufax, who only made five starts, threw 135 pitches in a two-hit shutout in which he fanned 14.

10. Koufax never pitched in the minors, because under the rules of the time he was considered a "bonus baby." The rule existed in various forms from 1947 to 1965 (when the draft was instituted), and stipulated that if a player's signing bonus exceeded a certain amount (originally $4,000) he had to spend an entire season (or two) on the major league roster. Yes, it was a dumb rule and certainly hurt many careers.

11. Four bonus babies turned into Hall of Famers: Koufax, Al Kaline, Harmon Killebrew and Catfish Hunter. Only Killebrew would go back to the minors.

12. As you would then guess, this era was rife with teenage pitchers (and players). Here is the list of teenage pitchers by decade:

2010s: 1

2000s: 1

1990s: 2

1980s: 8

1970s: 14

1960s: 54

1950s: 33

1940s: 33

1930s: 19

1920s: 27

1910s: 28

13. Besides Feller, Koufax, Drysdale and Hunter, other Hall of Fame pitchers (since 1913) who debuted as teenagers: Bert Blyleven, Nolan Ryan, Jim Palmer, Hal Newhouser, Early Wynn, Red Ruffing, Waite Hoyt ... and Babe Ruth. There were others prior to 1913, including Walter Johnson.

14. The single-season wins leader since 1913, however, is not one of those guys. It's Wally Bunker, who went 19-5 for the Orioles in 1964. The Orioles wanted to send Bunker back to the minors, but the Bonus Baby rules of that time said he could be claimed by another team. So Baltimore kept him. Unfortunately, in his final start of the season he hurt his shoulder warming up (probably a rotator cuff) and threw his last major league pitch at 26.

(If you want to go back to the 19th century, John Ward won 47 games at age 19 for the 1879 Providence Grays.)

15. Father and son teenage pitchers: Lew Krausse Sr. (19 years, 3 days when he debuted for the Philadelphia A's in 1931) and Lew Krausse Jr. (18 years, 52 days when he debuted for the Kansas City A's in 1961). Lew Jr. debuted in June, a few weeks after graduating from high school, and spun a three-hit shutout. Though he spent the rest of the season with Kansas City, he was wild and spent most of the next four years in the minors, hurt his elbow and would finish with 68 career wins.

16. Charlie Finley was the owner who signed Lew Jr. and he was still the owner in 1978 when the A's drafted Mike Morgan and Tim Conroy out of high school and promoted both directly to the majors. Morgan threw a complete game, but was shelled his next two outings and was sent down. He would end up with a 22-year career. Conroy made two stars before going down, all part of a wacky season for the A's.

17. The last time two teenagers started on the same day: June 11, 1984, when Gooden and Jose Rijo of the Yankees both started. The last time two teenagers started against each other: Sept. 28, 1965, when Hunter faced Joe Coleman of the Senators. Coleman won 6-1 (it was his major league debut).

18. We can't mention Dodgers teenagers from Mexico without mentioning Fernando Valenzuela. Fernandomania occured in 1981, but Valenzuela pitched 17.2 innings in relief as a 19-year-old in 1980. His ERA was 0.00.

19. Finally, the youngest teenager of them all: Joe Nuxhall, who debuted for the Reds in 1944 when he was 15 years old. (Yes, there was a shortage of talent during World War II.) Nuxhall walked five and allowed five runs in two-thirds of an inning in his only game ... but he would make it back to the majors eight years later and win 135 career games. He later served as a broadcaster for the Reds for 40 years.