Despite the recent struggles of the team, it’s an exciting time to be a Red Sox fan. The farm system is ready to start producing major-league talent at a rate that this franchise hasn’t seen since around the time Jon Lester, Clay Buchholz, Dustin Pedroia, Jacoby Ellsbury, and the rest of that crew came up and helped lead the team to the 2007 World Series title. The start of the current influx of young talent came last season, when third baseman Will Middlebrooks came up, and he did not disappoint.
Though a broken wrist in August cut his season short, when he was on the field he showed that he’s more than capable of holding his own against major-league pitching. In 286 plate appearances, he put up a .288/.325/.509 slash-line, with a 120 OPS+. Amongst all rookies with at least 250 plate appearances in 2012, his .357 weighted on-base average (wOBA) ranked fourth, with 25 players meeting those qualifications.
Middlebrooks’ offensive value comes from two primary places. Firstly, he does well at converting balls in play to hits. In his minor-league career, he never had a batting average on balls in play (BABIP) under .300 when he had at least 100 plate appearances. In his stint in the majors, his BABIP was .335, with a 21.5-percent line drive rate. The other place his value comes from is his power. His .221 isolated power (ISO) ranked seventh among the 45 third baseman with at least 250 plate appearances.
While he typically made good contact, and showed strong power in his rookie season, he didn’t show a great ability to draw walks. His 4.5-percent walk-rate was 3.5 points below league-average, which is not typical of players who show above-average power. To see what this means, I looked back to 2003-2011, and found every player who had a walk-rate below five-percent, but an ISO of at least .200 in a single season with at least 250 plate appearances. There were 21 seasons that fit this criteria, with the players ranging from the likes of Corey Patterson and Jeff Francoeur, all the way to David Wright and Adrian Beltre.
The first name from that list that jumped out to me was Wright. While he’s had some health issues over his career, his bat has been one of the best in the game when he’s been healthy. Unfortunately for Middlebrooks, the Mets’ third baseman’s rookie year was an anomaly. Other than 2004, he has always had an above-average walk-rate, including his 13-percent clip that he had in his minor-league career. Middlebrooks, on the other hand, had low walk-rates throughout his time in the Red Sox farm system.
Another interesting name on this list was Beltre, who probably represents something close to the best-case scenario for Middlebrooks. Beltre has been an above-average offensive player for the majority of his career, despite his walk-rates consistently coming in below-average. While he has always struck out less than Middlebrooks, he also didn’t possess the rookie’s power when he first reached the big leagues. Middlebrooks will never get to the out-of-this-world defensive level that Beltre has been at, but he’s no slouch with the glove, and could come relatively close to the Rangers’ third baseman in value if everything breaks right.
The worst-case scenario on the list, among the third baseman, is probably Joe Crede. He was never able to sustain the power needed to consistently post an ISO of at least .200, and his walk-rate never substantially improved. In addition, his ability to turn balls in play into hits was always sub-par, something that Middlebrooks should be able to avoid in his career.
Another name on the list was Mark Trumbo, who also met this criteria in his rookie season. Last year, his second in the big leagues, he improved his walk rate while keeping his ISO almost identical. It's obviously just anecdotal evidence, but his second-year adjustment led to big strides offensively, and even earned him an All-Star bid. Middlebrooks taking similar strides would surely boost his offensive value.
In the end, Middlebrooks is only coming off of his rookie year, and he didn’t even get a full season’s worth of playing time. Judging by some comparable seasons, one could put his ceiling to be something near Beltre's career, with a worse - but still good - glove. If he wants to realize the maximum amount of his potential, he is going to need to improve his walk rate at least slightly. With his power, ability to make good contact, and defensive value, he doesn’t even need to draw walks at a league-average rate to be a very good player. Since plate approach is a quality that typically improves as a player progresses through his career, Middlebrooks’ future should be bright.