Michael Bourn is in a hitting slump. In his last seven games, he has a triple slash line of .172, .226, .172. Most likely this is a just a blip on the radar screen, one of those valleys in the season of peaks and valleys. As I wrote previously, Bourn's BABIP suggests that the Astros' graceful centerfielder is likely to rebound offensively as some point in the future.
However, whenever Michael falls into a hitting valley, I look over his batting splits. Bourn has struggled during his career to maintain an acceptable offensive performance against lefthanded pitching. Over his career, Bourn's differential between hitting LH and RH pitching is 41 points of batting average (.269 vs. .228) and nearly 100 points of OPS (.693 vs. .595). To be fair, I can't say that Bourn's current slump is caused by LHP, since the Astros haven't faced an abnormal number (2 of 7) of lefthanded starting pitching in that time frame. But, if one were to look for areas to improve Bourn's overall offensive performance, his hitting against LHP is one place to turn. Two possible actions which could improve his overall offensive numbers: (1) starting Bourn less against LHP; or (2) asking the new hitting coach, Jeff Bagwell, to help him work on this part of his offense.
At this point of the 2010 season, Bourn's offensive splits against LHPs are horrendous. However, a "sample size" warning is always helpful when we examine mid-season batting splits. Bourn only has 65 plate appearances against LHP this season, and that's not enough to tell us anything definitive. Below are Bourn's stat line against LH and RH pitching this season:
Michael Bourn 2010 Platoon Splits
BA, OBP, SLG, OPS [BABIP]
vs. RHP .264, .336, .342, .678 [.323]
vs. LHP .196, .286, .250, .536 [.278]
Bourn's only HR was hit against a lefthander, by the way. The Astros' broadcasters have suggested that Bourn bunt against LHP, even to the point of bunting against a LHP with 2 outs and runners on 2d and 3d. While the suggestion may be worth considering, the opposing team is likely to be looking for a bunt when Bourn faces LHP. The opposing team may not be as prepared for a bunt in a 2 out RISP situation, however; so that strategy may have merit. In the first game of the Pirates' series, when Bourn came to bat with the runner on third and 2 outs, the Pirates' LFer played extremely shallow, presumably because Bourn isn't likely to drive the ball to LF with a LHP on the mound.
As a slight diversion from the platoon split issue, Michael's home and road splits this season are nearly as starkly contrasting as his left/right splits. Bourn's batting average is 35 points higher at home, and his OPS is .707 at home and .596 on the road. Because Bourn was a much better hitter on the road than at Minute Maid Park last year, I am skeptical that the home/road differential this year is meaningful. And, in case you are wondering, the Astros as a team are hitting better at Minute Maid than on the road (15 points of batting average and 50 points of OPS).
Returning to Bourn's platoon splits, let's consider one of the options I mentioned earlier. Now that Jason Bourgeois has replaced Cory Sullivan on the big league roster, the Astros now have a more intriguing possibility if they give Bourn more days off when the team faces LHP. The sample size warning applies to Jason, too, since he only has a career total of 76 plate appearances in the big leagues. But Bourgeois' splits at the major league level have been eye popping:
Jason Bourgeois Batting Splits (ML)
(BA, OBP, SLG, OPS)
vs. RHP .148, .258, .185, .443
vs. LHP .306, .390, .417, .807
Bourgeois also has large splits over his minor league career. In more than 2000 at bats, Bourgeois's offensive advantage vs. LHP is approximately 80 points of OPS and 15 points of batting average. Since Bourgeois can play CF well and is speedy, the Astros don't lose so much, in terms of base stealing and defense, if he replaces Bourn against LHP.
I realize that Michael Bourn is the Astros' all star representative and gold glove player. I would be reluctant to take too much starting time away from him. I'm not advocating that the Astros turn Bourn into strictly a platoon center fielder. However, I think it may be worthwhile to consider giving him more days off when lefthanders (particularly tough ones, with larger platoon splits) are the starting pitcher. This may provide benefit to Bourn, by raising his full season offensive stats, as well as providing the Astros with a better opportunity to evaluate Bourgeois' usefulness as a reserve outfielder.
Lefthanded hitters have some natural advantages at the major league level; in fact, many of the best hitters in history have been lefthanded. (As a lefthander, myself, I like to say that.) But, lefthanded hitters are more likely to have greater variation in their platoon splits than righhanders. As Rob Neyer has noted, this is an empirical fact. Neyer speculates on the reason for that difference:
Here's one theory (not my own, by the way) ... Growing up, right-handed batters face mostly right-handed pitchers, and so they get used to them. When they reach the minor leagues, it's not easy to hit a curveball or slider thrown by a right-handed pitcher ... but at least they've seen those pitches before. But there are very few left-handed pitchers in Little League, and few even in high school. So when a left-handed hitter enters professional baseball, having already spent many years learning to hit, he will probably have faced very few left-handed pitchers. And very few good left-handed curveballs and sliders.
As one lefthander to another, Michael, take heart in the fact that lefthanders tend to be higher achievers. Four (Obama, Clinton, H.W. Bush, Ford) of the last seven U.S. Presidents were lefthanded and a fifth was ambidextrous (Reagan).