Looking Back on Brandon Belt's 2010 Season

"Brandon Belt, opening day first baseman for the San Francisco Giants."

I didn't think I'd hear that 'till 2012, to be honest. I figured the Giants would have him begin the year in Fresno and call him up the same way they did with Buster Posey last season. But when you produce in the Minors the way he did, rake in the Arizona Fall League, rank 23rd on Baseball America's Top 100 Prospects list, and hold your own in Spring Training...well, you're going to stand a pretty good chance at making the Major League roster.

Belt really opened a lot of eyes with his swift ascent through the minors last year - I mean, he really hit the snot out of the ball.  A .352/.455/.620 batting line is outstanding by pretty much any standards. That's just awesome production. He hit about 82% better than the league average in 2010- to give you some perspective, Ted Williams hit approximately 89% greater than the league throughout the course of his entire career.  And when you hit like Teddy Ballgame, you're going to get noticed.

Just how good was that season, though?  And does this mean he'll hit just as well in the majors?

I think one of the most important principles of sabermetrics is context.  It's extremely important to know - I mean, if you think about it, hitting .240 back in 1968 really wasn't such a bad thing when you realize that the league hit .237. And hitting .300 in 1894 really wasn't all that special, especially when you consider the average ballplayer hit .309.  This holds especially true for Minor League statistics. Remember how Eugenio Velez hit .315/.369/.557 in A Ball back in 2006, and quite a few people got excited?  Yeah, he was 24. The average hitter in that league was about 22 years old. It was a good season, sure, but not nearly as impressive as it might look at first glance.

As we all know, not all levels of the minors are equally difficult. Double-A is more difficult than High-A, of course, just as High-A is more difficult than, say, short-season ball. So when we begin to look at the statistical performance of players in the minors, we have to consider the relative difficulty of the league the player was in when he posted his numbers. This is where Major League Equivalencies (MLEs) are quite useful. MLEs look at how performance typically translates from one league to another, while "correcting" for the effects of the player's home park, and then estimate the impact of their new park on their batting (or pitching) line. 

There are a few different online calculations of League Equivalencies- one being Baseball Prospectus' Davenport Translations, Brian Cartwright's MLEs, Dan Szymborski's ZMLEs (I think I got the name right- sorry, Dan, if I'm off), and Jeff Sackmann's Minor League Splits, which have recently been brought back to life by Driveline Mechanics.  For the purposes of this little exercise, I'll only be looking at Sackmann's MLEs.  There's no particular reason why - Sackmann's have always been pretty popular, and I guess I feel like going with the crowd.

Context, context, context.  Here's some for ya- below is a chart of the "difficulty ratings" of the different leagues used by Sackmann in his MLEs:

These figures suggest that a player from the International League retains about 73% of his IL performance when he reaches the Major Leagues, and that a player from the PCL only produces at 68% of his Minor League production. I believe Sackmann's way of deriving figures for the mid to lower minor leagues is through a process called "chaining," which looks at the production of players moving from one league to the next.  What this allows us to do is really take into consideration the difficulty of the league the player was in. A guy that hits .320 in AA isn't as impressive as a guy that hits .320 in AAA, but this begins to give us some semblance of an idea about just how different they really are.

Belt's untranslated batting line - assuming he hit in the Majors the same way he did in the Minors- would translate to a wOBA of about .463; approximately +66 runs above an average hitter. That's a Pujolsian season. His translated line suggests he hit the equivalent of a .244/.329/.406 hitter in the majors. His overall line:

These numbers are park-neutral, meaning there's no estimate being made for the impact of AT&T Park.  This is actually a pretty good line- despite the lower average, the MLE suggests Belt would still produce with more power than a league average hitter and still walk 10% of the time. That makes me quite happy. For wOBA fans, this equals a .328 wOBA (league set to .330), essentially a league average hitter. For a 22-year-old, that's not bad at all.

Of course, this got me thinking: what about some other players with gigantic minor league campaigns?  How does Belt compare?  Because Minor League splits only goes back to 2005, I'm limited to only those years- and since Belt was in the running for Baseball America's Minor League Player of the Year, I thought it would be interesting to compare his season to previous winners of the award. This group consists of Atlanta's Jason Heyward, Baltimore's Matt Wieters, Cincinnati's Jay Bruce, Kansas City's Alex Gordon and Minnesota's Delmon Young.  All very highly-rated prospects; all with monster seasons.

Belt was 22 last year, which makes his closest comparables in terms of age both Matt Wieters and Alex Gordon. Of the group, Wieters posted the most impressive season, with Gordon not far behind. Heyward, Bruce and Young represent the younger group. Belt's season was second-to-last. So while he still had a phenomenal year, the quality of the leagues he was playing in suggests his performance may not have been at the same level as some of the very top minor league prospects of the past five years. This doesn't take away from Belt's season, of course.  Young, Gordon and Wieters haven't exactly performed as well as many thought they would, while Bruce and Heyward are still coming in to their own.

The main lesson to be learned? Brandon Belt had one heckuva season, but it was less impressive than prospects that were rated higher than he, and with performances estimated to be more impressive. And that having a phenomenal season in the minors doesn't necessarily mean that it will immediately translate into Major League success. As we've seen with Young, Gordon and Wieters, having big seasons, remarkable tools, and high rankings on prospects lists doesn't always mean much. And to expect Belt to light the world on fire right off the bat might be a bit much.

I have to say that I agree with what the major forecasting systems predict for Belt in 2011:

The overall average forecast for Belt has him at .267/.353/.447.  PECOTA lists his closest comparables as Wieters, Jeremy Hermida, Jason Thompson, Nick Markakis, Willie McCovey, Gordon, Frank Robinson, James Loney, Brian McCann, and Darryl Strawberry. There are some reasons to be optimistic from some of the players listed, but there are reasons to be a bit worried as well. Having Wieters and Hermida back to back as his closest comparable players may make you want to temper your expectations a bit.

The season is still young, of course, and there's always the matter of small sample size - I mean, heck, we're not even a quarter of the way through the season - but Belt is showing a very disciplined approach at the plate and hasn't seemed overwhelmed by big league pitchers so far.  I think he stands a better chance at having a Jason Heyward type of rookie campaign than he does an Alex Gordon.  But maybe that's just the optimist in me.