When can you say bust?

I came across a stat the other day that took me by surprise. Someone on Twitter was defending Starlin Castro, and made the point that he’s already amassed 1,000 hits before his 25th birthday. I thought, "Surely, that can’t be true. Surely, Starlin Castro isn’t already one-third of the way to a milestone that all but guarantees one’s place in the Hall of Fame."

Turns out that’s not entirely true. But this is:

846 hits! Not bad, Starlin Castro. Especially considering it was around this time just a year ago when many were leaving Castro for dead after one of the worst offensive seasons by a shortstop in recent history. In hindsight, that notion seems like quite the overreaction, given that Castro followed up the dreadful year with the best of his career and has re-cemented himself as the young, exciting Cubs shortstop of both present and future.

But Castro’s case got me wondering: Do we, as a community, take young talent for granted? Are we too quick to write off young players as one-hit wonders who burst onto the scene and then struggle? Especially when those struggles last for a full season or more? Seems to have been the case with Castro. Surely, I thought, there are others like him.

Naturally, my attention then turned to Bryce Harper.

Google the internet for the keywords "Bryce Harper bust" and you’re met with about 492,000 results in less than half a second. Obviously, we all know how Google works, so this isn’t to say that there are nearly half a million instances of people calling Harper a bust, but it doesn’t take long to find countless examples of people ready to write off the 22-year-old as a "bust." Even the players think he’s overrated.

Of course, terms like "overrated" and "bust" are entirely subjective. Maybe, through one person’s eyes, anything less than Mike Trout makes Harper a bust. A player can be considered "overrated" and still be very good. But is it at all fair for Harper, who’s still never faced a pitcher younger than himself, to be hit with a bust label already? After all, he’s still nine months younger than Kris Bryant — who three MLB executives would already choose over Harper to build a franchise around — and Harper has 55 career homers and 10 Wins Above Replacement under his belt.

To be fair: Yes, given the expectations, last year was a disappointment for Harper. Last year was supposed to be the year when he finally stayed on the field for 150 games and put it all together. Instead, he missed 57 games due to thumb surgery and struck out more than ever, while dropping more than 50 points off his isolated slugging percentage. For many bust-labelers, that was the last straw.

But if history is any indication, it’s way too soon to write off a young talent who’s already proven he can hit major-league pitching, and hit it well. In fact, as it turns out, many of the game’s best hitters today went through similar rough patches after early successes.

I enlisted the help of FanGraphs database guru Jeff Zimmerman to construct a pool of comparisons for Harper. I wanted to look for batters, and I wanted to look for batters under the age of 25. We’re looking for good batters, so they needed to have already shown the ability to hit MLB pitching at a league-average-or-better level, and so I set a minimum weighted on-base average of .320. Then, I looked for instances where this young batter dropped at least 30 points off his wOBA, only to regain at least that much the following season. To keep things recent, we’re looking at just 2000 and on.

Those were just words. This is the table:

Name Starting_Year Starting_Age wOBA (Yr1) wOBA (Yr2) wOBA (Yr3)
Bryce Harper 2013 20 .371 .338 ???
Giancarlo Stanton 2012 22 .405 .368 .403
Starlin Castro 2012 22 .323 .280 .341
Eric Hosmer 2011 21 .343 .291 .350
Jason Heyward 2010 20 .377 .313 .351
Matt Kemp 2009 24 .362 .329 .413
Justin Upton 2009 21 .385 .349 .385
Melky Cabrera 2009 24 .329 .292 .350
Asdrubal Cabrera 2009 23 .351 .303 .344
Pablo Sandoval 2009 22 .399 .316 .383
B.J. Upton 2008 23 .351 .306 .328
Troy Tulowitzki 2007 22 .364 .321 .395
Ryan Braun 2007 23 .421 .376 .403
Prince Fielder 2007 23 .419 .371 .422
Jeff Francoeur 2007 23 .338 .288 .315
Robinson Cano 2007 24 .362 .311 .374
Joe Mauer 2006 23 .396 .352 .379
Brian McCann 2006 22 .401 .329 .386
Jhonny Peralta 2005 23 .378 .312 .337
Corey Patterson 2004 24 .329 .261 .322
Juan Pierre 2001 23 .350 .304 .328
Aramis Ramirez 2001 23 .374 .287 .337
Juan Encarnacion 2000 24 .333 .300 .335
Edgar Renteria 2000 23 .337 .298 .349
Andruw Jones 2000 23 .387 .328 .377

As expected, not all of these are perfect matches. Some guys, like Stanton, Fielder, and Braun, were coming from such a high place that their year-two dropoffs weren’t at all worrisome. Some guys, like Pierre, Renteria, or Patterson, were just completely different hitters than Harper. And others, like Francoeur and Encarnacion, were never able to sustain the success they had, lost, and recovered at a young age.

But there’s still a lot to be learned from this table. Back in 2009, a 21-year-old Justin Upton took MLB by storm, going 20-20 with an adjusted batting line 30 percent better than league average. The following year, he plummeted back to earth, posting league-average numbers over 133 games. I think we can all agree that he’s turned out alright.

Or how about in 2007, when 22-year-old Troy Tulowitzki slugged 24 homers in his rookie season, only to experience an injury-riddled season the next year — similar to Harper — with his production suffering immensely. Since then, Tulowitzki’s been one of the 15 best hitters in baseball.

Matt Kemp? Same thing. Awesome at 22 and 24, barely league-average the seasons after. Since then, he’s been an amazing hitter when healthy. Robinson Cano, after three years of crushing big-league hitting, was a below-average hitter in his age-25 season. He rebounded the next year and has been the best second baseman since.

The jury is still out, to an extent, on whether guys like Jason Heyward and Eric Hosmer will sustain long-term hitting success. But both, like Harper, were considered huge prospects when they came up. Both destroyed big-league pitching from the get-go, only to each have absolutely miserable seasons the year following. Both bounced back strong the next year, and the future is as bright as ever for each.

It’s worth noting, too, that not only did Harper debut at a younger age than every player on this list, but that his "down year" is also the sixth best, offensively, of the 25 names in that table. Tulowitzki and Cano were both well below league average at the plate in their down years. Harper’s down year was still 15% better than league average.

The big picture here is far from a revelation. Exceptional talents debut at exceptionally young ages for a reason. They’re often good enough to skip the upper levels of the minor leagues and go straight to the majors, and so they do. Once they get there, their talent sets the world on fire until pitchers adjust. Often it’s the first time in the young hitter’s career that pitchers successfully adjusted to them.

Justin Upton had never seen a pitch above Double-A when he broke into the bigs. Kemp had fewer than 400 plate appearances above A-ball. Harper barely had 200. Instead of these hitters working out the kinks in the high minors, we see them do it on the fly in the big leagues. And because of their exceptional talent, they do. This is why projections peg Harper one of the 15 best hitters in the league this season, despite the down year.

Justin Upton was fine. Matt Kemp was fine. Robinson Cano and Troy Tulowitzki, way more than fine. Jason Heyward and Eric Hosmer look like they’re going to be fine. Bryce Harper? He’s going to be just fine, too. And chances are, using the word "fine" to describe Bryce Harper might end up being an understatement as egregious as already labeling him a bust.