In his age 20 season, 2010, Jason Heyward produced 5.2 Wins Above Replacement, according to baseball-reference’s formula (5.1 using the fangraphs formula). That’s All-Star level production for a player of any age, and extremely high production for a twenty-year-old. More on high-WAR 20-year-olds, and their future, after the jump.
All-Time Highest bWAR in Age 20 Season, Non-Pitchers:
1. Alex Rodriguez (1996) 9.4
2. Al Kaline (1955) 9.0
3. Ty Cobb (1907) 8.4
4. Mel Ott (1929) 8.0
5. Ted Williams (1939) 6.8
6. Mickey Mantle (1952) 6.6
7. Vada Pinson (1959) 6.3
8. Frank Robinson (1956) 6.2
9. Sherry Magee (1905) 6.0
10. Jayson Heyward (2010) 5.2
11. Rogers Hornsby (1916) 4.8
12. Johnny Bench (1968) 4.7
13. Ken Griffey, Jr. (1990) 4.6
14. Claudell Washington (1975) 4.6
15. Jimmie Foxx (1928) 4.6
How did these young stars do in their next season — their age 21 year? 13 of these 15 players were again over 4.5 WAR in their age 21 season. The only two of these guys who fell to less-than-star level in their age 21 season were Jayson Heyward (2.0 WAR in 2011) and Claudell Washington (0.3 WAR in 1976). In terms of full careers, here are how the guys above have done in terms of career WAR (not counting Heyward, who is only 22):
1. Ty Cobb 159.4
2. Rogers Hornsby 127.8
3. Ted Williams 125.3
4. Mickey Mantle 120.2
5. Mel Ott 109.3
6. Frank Robinson 107.4
7. Alex Rodriguez 104.6
8. Jimmie Foxx 94.1
9. Al Kaline 91.0
10. Ken Griffey, Jr. 78.6
11. Johnny Bench 71.3
12. Sherry Magee 59.1
13. Vada Pinson 49.3
14. Claudell Washington 18.2
Again, Claudell Washington is the one obvious outlier of the group, the one who fell seriously short of major stardom. Claudell was a fine player, who played seventeen years in the majors combining speed with decent power. He was extremely athletic, lean and muscular, the classic multi-tool guy. While his strike zone judgment wan’t great, he was injured often, and he was one of many caught in the cocaine scandals of his era, he was usually a productive player. Bill James ranked him 84th among right fielders all-time in his New Historical Abstract and pointed out that despite his decent productivity Claudell was considered a disappointment throughout his career because he never lived up to the promise of that season he had as a 20-year-old. Can Jayson Heyward, who is apparently now being platooned, recover the level of performance he achieved in 2010, or will he suffer a fate similar to Claudell’s?