When wondering how Eric Hosmer and Mike Moustakas will perform next season and beyond, it might be instructive to look back on the early years of Billy Ray Butler. Like Hosmer and Moose, Butler was a first-round, high school draftee, who became a highly touted prospect and made his Major League debut at a very young age. Heading into the 2007 season Baseball America rated Butler the #25 prospect in baseball.
Butler's career should offer some perspective when it comes to forecasting Moustakas and Hosmer in 2012. Sometimes, whether we want it or not, players take time.
Here are Butler's first three seasons:
Butler's composite line in his first three seasons ended up being .291/.346/.451, which ends up very near his rookie year performance. However, to get to that composite, Butler languished through a rough sophomore season (which included a demotion), when his power trailed off. That age 23 slugging percentage of .492, is still the highest of Butler's career. In 2010-11, Butler remained near his 2009 level, which it now seems, may be his peak. (Jeff had a great post on Butler's future a few months back. Read it.)
Butler's groundball rate is much discussed, both as a limit to his power and as a problematic source of double plays. In his first three seasons, his GB rate bounced around between 48-51 percent. Curiously, that is similar to what Eric Hosmer did last season, hitting ground balls 50.9% of the time (according to Stat Corner). Hosmer's 19 homers in a partial season as a rookie suggests that he has greater power potential than Butler (who has a career high of 21 HRs) but he may have also benefited from some HR/FB luck. The Hos homered in 8.7% of his balls in the air, a tick or two above the Major League average of 6.5%. Along the same lines, I expected Moose to have a high ground ball rate, since he was seemingly making weak contact for two months straight to begin his career, but his GB rate was much lower, at just 39.2%.
Last season, Hosmer hit an encouraging .293/.334/.465, a slash line that is actually very close to what Butler posted as a 21 year old his rookie year. Just as Hosmer's power was encouraging, his unintentional walk rate was a little discouraging. Hosmer earned a true walk in just 4.8% of his PAs, (MLB average 8%). This figure was actually lower than Moose's 6.0%, despite the respective reputations for each player. Although Moose was less of a hacker than we expected, his .263/.309/.367 line as a 22 year old didn't set the league aflame. I called for the Royals to demote Moose in mid August, but basically from that point forward, he hit much better.
Analysis by anecdotal comparison is generally awful, and that isn't what I mean to do here. Butler is one player amongst thousands, and while he does have some traits in common with both The Hos & The Moose, any true projection would factor in thousands of data points (as they already do). However, I think what Butler can illustrate, and this is an important point, is that prospect development and player careers in general, are not linear. Hosmer might simply keep getting better and better and better for years to come, but he might not. With extremely young players, there are still potentially major changes to come in their skillsets and approaches, and there's also more initial room for pitchers and scouting reports to gain the upper hand for the next few months or years.
Just look at Butler. From the beginning, because he's really a classic hitting prospect who has had constant playing time (so unlike Gordon there's no complicating factors) we've tried to graft some narrative onto his career. He's been hyped and critiqued, over-rated and under-rated, and points in between. Butler has had his ups and downs, and despite his physique, it now seems like he's just not going to be an extreme power hitter. He's a doubles machine who can hit for average despite being slow. But the crazy thing is, he's still young enough that that could change again.
Just something to keep in mind with Moose and Hosmer...