Yamamoto's stats in Japan compared to Ohtani's

Here are his stats in Japan compared to Ohtani's pitching stats in Japan (both Pacific League)  

Stat    Yam    Oht
ERA    1.82    2.52
IP    897    543
H    633    384
HR    36    24
BB    206    200
IBB    2    0
SO    922    624
HBP    25    23
BF    3488    2187
WHIP    0.935    1.076
H9    6.4    6.4
HR9    0.4    0.4
BB9    2.1    3.3
SO9    9.3    10.3
SO/W    4.48    3.12

Pitchers who led their league in WAR at age 21 or younger (and Britt Burns is one of them)

I looked at the AL/NL since 1900. 

First, I went to the annual leaders page at Baseball Reference. Then sorting each league on the WAR for annual leaders, I found that 5.5 was the lowest leading total not counting 2020, the Covid year.

Then I did the following search at Stathead:   

For single seasons, since 1900, age 21 or younger, Playing in the AL or NL, in the regular season, requiring Wins Above Replacement (WAR) >= 5.5, sorted by descending Wins Above Replacement (WAR).

That guaranteed that I would get all the guys 21 and younger who led their league in WAR since anyone with 5.4 WAR could not have been a league leader. The results put WAR in bold face if the guy was the leader. There were 23 cases. 9 of them were league leaders. Here they are. 

Player	WAR	Year	Age
Christy Mathewson	8.9	1901	20
Bob Feller	9.2	1939	20
Bob Feller	9.9	1940	21
Don Drysdale	6	1957	20
Mark Fidrych	9.6	1976	21
Britt Burns	7	1980	21
Dwight Gooden	5.5	1984	19
Bret Saberhagen	7.1	1985	21
Dwight Gooden	12.2	1985	20

 

Burns is probably, by far, the least known. Mathewson, Feller and Drysdale are Hall of Famers. Gooden and Saberhagen won Cy Young awards. 

Fydrich was famous in his rookie year for his mound antics like talking to the baseball. When he started, Tiger Stadium was usually packed. He started the All-Star game for the AL in 1976. He was also rookie of the year

Burns made the AL All-Star team in 1981 but did not pitch. He was 5th in pitching WAR that year.

His last season was 1985 when he won 18 games at age 26. According to Wikipedia, a chronic, degenerative hip condition pretty much ended his career.

Here are all the guys who won 15+ games in their last season at age 29 or younger since 1900 in the AL/NL:

Player	W	Year	Age	Team
Lefty Williams	22	1920	27	CHW
Britt Burns	18	1985	26	CHW
Ed Doheny	16	1903	29	PIT
Jose Fernandez	16	2016	23	MIA
Ted Lewis	16	1901	28	BOS
Jay Hughes	15	1902	28	BRO
Win Mercer	15	1902	28	DET
Mike Sirotka	15	2000	29	CHW
Monty Stratton	15	1938	26	CHW

4 of the 10 cases are the White Sox. Click here to see the search results from Stathead.

Lefty Williams was banned as part of the Black Sox scandal.

Ed Doheny suffered severe mental health problems according to his SABR bio by Seamus Kearney & Tom Simon.

Jose Fernandez died tragically in a boating crash.

After 1901 "Lewis retired from baseball to devote his full energies to teaching" according to his SABR bio by Rory Costello.

Hughes chose to pitch in the minors according to his SABR bio by Bill Lamb.

Mercer committed suicide according to according to his SABR bio by William Akin.

Sirotka had a shoulder injury that ended his career according to Wikipedia.

Stratton's case is famous (Jimmy Stewart starred in a movie about him). He lost part of his leg in a hunting accident.

There are only 3 guys at age 22 who led their league in pitching WAR since 1900 in the AL/NL:

Sam McDowell 1965 AL 8.2

Bert Blyleven 1973 AL 9.8

Mark Prior 2003 NL 7.4

Click here to see the search results