We may look back and think that it means a LOT.
Very few future greats have had excellent years at 19. Mel Ott and one or two others. That made Harper 's '12 stand out a LOT. But many of the best players have errupoted with amazing seasons at 20. If Harper really is one of those players, here are some of the numbers by great players at age 20 __all roughly as good as Mike Trout last year at 20.
Mel Ott: 42 homers, 151 RBI, 113 walks, .328, 1.084 OPS.
The late Vada Pinson: 131 runs, 205 hits, .316.
Frank Robinson (same high school as Vada, long-time friends): 38 homers, 122 runs.
Mantle: .311, 3rd in MVP voting.
Tony Conigliaro: 32 homers (AL champ).
Orlando Cepeda: .312, 38 doubles, 25 HR.
Al Kaline: .340, batting title.
Ted Williams: 131 runs, 31 homers, 145 RBI!, .327.
Ty Cobb .350. Rogers Hornsby .313. Jimmy Foxx .328. Pudge Rodriguez All-Star and Gold Glove.
A-Rod: the amazing 141 runs, 54 doubles, 36 homers, 123 RBI and hit .358 while playing shortstop!
At 20, Babe Ruth went 18-8 with a 2.44 ERA and got into the World Series with the Red Sox. In 92 at bats, he hit .315 with a .952 OPS. So, he was already The Babe.
The list goes on and on. In Harper's last 41 games last year, he hit .327 with a 1.045 OPS __the same EXACT OPS that A-Rod and Ted Willaims had at 20. (Only Ott was higher.) On the other hand, Harper had one terrible long slump last year in mid-season before he got hot that lasted 39 games when he hit .198 with a .547 OPS. So, he can get hot enough to be great at 20. Can he minimize his slumps well enough?
But the possibility of an outlandish season is not outlandish! There is FAR more precepdent for a remarkable season at 20 than there is at 19.
But, of course, a zillion exceptional players have NOT been wonderful at 20. So if he's only slightly better than '12, it doesn't mean he won't be much better by '15 or '16. He's a learner and a worker. As long as he stays that way, and I assume he will, he'll keep getting better.
Vada