I haven’t really seen many serious articles on this topic, which is really good (because it’s a dumb question). However, I feel like some fans are starting to have doubts about how good he is after this year. I’ve seen people point out a number of ways that he hasn’t “lived up to the hype” so far, though.
Again, it’s usually more from commenters than writers (I have long speculated I would be a happier person on the whole if I refrained from reading internet comments). But I’ve still seen the gamut of complaints, from people criticizing his selection to the All-Star Game (already his second, mind you) to “only” hitting .273 with 49 RBIs.
In some ways, it legitimately feels like a step back from his 2012 debut. He’s only managed 102 games this year thanks to injuries, while he played in 139 last year even with a late call-up. That actually is a legitimate concern; if there is anything that’s going to keep him from a Hall of Fame career,* it will be his own body.
*Note: he’s already on his way to the Hall of Fame median for career WAR...for someone four years older than him.
There are other reasons to feel some level of disappointment, though. For example, 6 of ESPN’s 43 experts predicted him to be the MVP this season. I don’t think I went that far (I can’t find an article I wrote predicting that either way), but I also don’t think I put it out of the realm of possibility. Both Baseball-Reference (5.2 WAR to 3.2+) and Fangraphs (4.5 WAR to 3.4+) say he’s been less valuable overall this year than last year.
It’s worth considering what’s gone in to that calculation, though. For example, he’s been playing hurt all year. On a rate basis, he’s almost identical to last season (Fangraphs says .033 WAR/G in 2012 versus .032 this year, while B-R stands at a not too overwhelming .037-.031 difference). And what’s almost as important is the composition of that value.
Last year, every fielding metric was a huge fan of Harper’s play in left and center, with both forms of WAR giving him over a win. This year though? Fangraphs has him as a slight positive, while B-R has him on the negative side (possibly due to playing more of left field and less of center, which means more of a positional hit). And really, that’s been almost the entire difference between his value last year and his value this year. He’s actually hit so much better this year that it’s almost offset the lower playing time. While Harper was a good hitter last year (.817 OPS, 118 OPS+, 121 weighted Runs Created+), he’s hit better in just about every way imaginable way this year (.878 OPS, 140 OPS+, 144 wRC+).
A 20-year old hitting 40% better than league average is always something to get excited for. His 144 wRC+ would rank eleventh all-time for someone 20 or under, just behind Frank Robinson in 1956. Granted, there’s a good chance Harper falls just short of qualifying for the batting title, but he’ll miss by just a little, and it’s impressive regardless. The ten players with better 20 and under batting seasons are all Hall of Famers (or Mike Trout or Alex Rodriguez), in case you needed another reason to be excited about what’s to come from him.
Really, if Harper's been a disappointment, it's only because baseball fans were spoiled last year by Trout. So maybe Harper didn’t follow in Mike Trout’s footsteps in being the best player in the league as a 20 year old. He could always follow Trout’s legacy of being the best in the league at 21. More realistically, even if he doesn’t put up a 10-WAR season next year, that doesn’t mean that we can’t also appreciate just how historically good he’s been already. And don’t let any nay-sayers tell you he hasn’t been already.