Boston Red Sox first base prospect Lars Anderson entered 2009 as the top overall prospect in the system, according to Kevin Goldstein at Baseball Prospectus. Anderson, 21, had originally been signed to an over-slot deal after being selected out of high school in the 18th round of the 2006 amateur draft.
In pre-2009 comments, Goldstein stated, “He projects for big numbers in all triple-slash categories, and should come lumbering into the middle of the Boston lineup by 2010.”
I was even more aggressive in my adoration of Anderson prior to 2009 and said, “Lars Anderson is the club’s top prospect and he could be knocking on the big-league door by mid-2009… He had an impressive walk rate of 17.9 BB%, but struck out at a rate of 32.3 K%.”
Interestingly, it wasn’t Anderson’s strikeout rate that doomed his 2009 season. It actually dropped from 32.3 K% in 133 double-A at-bats in 2008 to 25.5 K% this season. His walk rate was lower, but it remained more than respectable at 12.4 BB%. The most glaring drop was in the batting average. It dipped from .317 in high-A/double-A in 2008 to .233 in double-A in 2009. His BABIP played a huge part in the shift as it went from .367 (A+) and .435 (AA) to .293. His line-drive rate went from 19.9% (cumulative) last year to 13.0% in ’09.
It’s clear that Anderson’s small sample size numbers at double-A in ’08 (.316/.436/.526 in 133 at-bats) helped to gloss over the impact that the launching-pad-known-as-Lancaster had on his numbers (.921 OPS). That success may have very well buoyed his confidence for his late-season promotion. Even so, a .250 drop in OPS is shocking to the system. After slugging five homers in 133 double-A at-bats in 2008, Anderson hit just nine all year in ’09 in 447 at-bats. His ISO dropped from .200 to .112.
The good news is that Anderson’s plate rates held strong despite his struggles. His pre- and post-All-Star numbers are so different that it’s easy to speculate that a hidden injury may have been the root cause for the steep decline (.272/.366/.413 vs .154/.250/.208). The really good news is that Anderson played the season at the age of 21, so he has plenty of time to turn things around. Incumbent first baseman Kevin Youkilis or even Casey Kotchman can easily hold down the fort until the youngster is ready. He’ll just have to watch over his shoulder for Anthony Rizzo.
Marc Hulet has been writing at FanGraphs since 2008. His work focuses on prospects and fantasy. Follow him on Twitter @marchulet.