The Red Sox did it in 2004, and again in 2007 (with all due respect to an electric Jon Lester). The Cardinals did it in 2004, and again in 2006 (with all apologies to a fading Mark Mulder). The 2004 Yankees did it. So, coincidentally, did the last Rangers team to make the playoffs. What was it? Winning without consistently featuring a left-hander in the starting rotation.
The Rangers' desire to head into Opening Day with a southpaw starter has been something of a media and message-board meme this spring. Assuming right-handers Rich Harden, Scott Feldman, Colby Lewis, and Tommy Hunter have starting spots locked down (not necessarily a safe bet, granted, but one we'll make for the sake of argument), only one opening remains in the rotation. And even if it means losing the right-handed Brandon McCarthy to waivers, many folks apparently want to see Matt Harrison, Derek Holland, or C.J. Wilson get the nod for that final spot.
Why? Let's set aside residual resentment over the John Danks deal, the lingering worry that McCarthy will break (again), and the not unreasonable fear that even if McCarthy doesn't break (again), he simply won't be very good. The abiding concern is that Texas will struggle to contend without a lefty in its starting five. Over the course of a series, this argument runs, sending a left-hander to the mound every fifth day keeps opposing managers and batters honest, and helps limit the damage wrought by opponents' left-handed sluggers.
Or, as the Dallas Morning News' Tim Cowlishaw wrote last Saturday,"There's no question that having a left-hander in the mix is ideal. Going into series after series with three right-handers throwing cut fastballs ... makes Texas too predictable." (In fact, the scenario bothering Cowlishaw is likely to unfold regardless: Feldman, Lewis, and Hunter all feature cut fastballs, and McCarthy recently added the cutter to his arsenal.)
The importance of a left-handed starter is conventional wisdom -- but does it bear out? The examples we started with might suggest not, but they also come off as so much anecdotal evidence. Can we say anything more certain about the Rangers' 2010 starting situation, without resorting to such questionable comparisons? It's relatively straightforward to measure how well an individual starter is performing, but how should we measure the reciprocal interactions between a lefty starter and his right-handed colleagues (or, for that matter, the bullpen)?
Coming up with a definitive solution to the southpaw scenario is tricky. There's no obvious way to pull what Tom Tango calls a WOWY -- a "With or Without You" analysis, which compares outcomes in the presence of a factor, and then in its absence -- within a rotation or pitching staff. And there are too many confounding variables to cleanly analyze the effects of handedness in rotation composition across teams and seasons.
Resigning ourselves to these facts, what we can do is to examine the case for a lefty on its merits. Let's take a look at how the Rangers' four candidates for fifth starter have performed versus right- and left-handed batters over their careers. In the table below, we see selected platoon splits for Harrison, Holland, McCarthy, and Wilson. Juxtaposing Wilson's numbers with the rest is not exactly an apples-to-apples comparison, of course, since he's likely to fare differently as a starter than as a late-inning reliever. Still, these data give us a point of departure:
Harrison and Wilson both show fairly distinct platoon splits in these skill stats, which are the best approximations of pitchers' performance independent of defense and luck. In almost every category, Harrison and Wilson performed better against lefties than versus righties.
McCarthy was fairly consistent across the board -- his numbers aren't much worse (or, depending on your level of residual resentment, better) versus left-handed batters than against right-handed batters. In fact, his career xFIP shows a slightly reversed platoon split.
Holland's stats are more of a mixed bag. There are signs that in his rookie season, he struggled more versus left-handed than right-handed opponents. But the relatively small differential in Holland's xFIP platoon split is encouraging. In 2009, he was unusually prone to serving up gopher balls to right-handed batters on fly balls (and those batters hit lots of fly balls off him). xFIP accounts for this higher-than-expected HR/FB ratio against righties, which is likely to regress toward the league average of 10-12 percent in 2010.
All in all, the numbers suggest that Harrison and Wilson are good to go against lefties, but could labor against righties. They imply that McCarthy probably is what he is -- and that's roughly the same against hitters on either side of the plate. And they confirm that Holland could very well be in for a breakout season, especially if his long-ball tendencies normalize. But even these observations still don't provide as much clarification as we might like about the importance of including a left-hander among Texas' starters.
For more, let's take a look at the platoon splits for the two right-handed starters Texas expects to lead its rotation in 2010: Scott Feldman and Rich Harden. We have both Feldman's career and 2009 numbers listed, since considering his 2009 breakout season separately seems useful:
The small differences stand out. Neither Harden nor Feldman (especially in 2009) have been hit especially hard by lefties, even in comparison to Harrison, Holland, and Wilson. It's worth noting that the cutter Feldman broke out last season -- according to FanGraphs, the most effective pitch of its type in the majors last season -- was noted to be especially tough on left-handed batters. Also notable: Feldman's relative success against right-handed batters in 2009 may have been misleading. Only six percent of the fly balls Feldman gave up to right-handed batters went for home runs, which is much lower than expected – and, as a result, so were his HR/9 and FIP versus right-handers. (This is the opposite of what we saw above with Holland.)
What, in the end, do these two tables tell us about the Rangers' need for a left-handed starter entering 2010? First, they indicate that in Harden and Feldman, the Rangers have two right-handers who present distinct challenges to hitters of either handedness. This pokes a hole in the argument that Texas absolutely needs a left-handed starter to keep opposing lineups off balance. Second, it indicates that whatever Texas would stand to gain against left-handers by going with Harrison, Holland, or Wilson, it would likely give something away against right-handed batters. The Rangers have to ask themselves exactly how much of a penalty against righties they would pay in games started by any one of these pitchers. Given what Harden and Feldman already bring to the table, would that cost exceed the benefits relative to McCarthy?
There are no easy answers to these questions ... but here's one take. For the Rangers to maximize their chances to reach the post-season for the first time in over a decade, they need to break camp with the starters they believe will perform best from the word go. Maybe that means giving the fifth spot to Holland, whose potential and peripherals are undoubtedly promising. Maybe it goes to Harrison, boasting a newly svelte silhouette and spring success. Perhaps it's even Wilson's, given his talent and tenacity.
Handedness, however, shouldn't be a leg up for any of the trio -- not least because it's very difficult to believe the Rangers will rely on only five starters the entire season, especially if the Opening Day rotation features both Harden and McCarthy. The 2007 Jon Lester may prove an instructive example, after all. It's certainly not a stretch to anticipate Holland (or Harrison) starting the season in Triple-A, getting the call to replace an injured or ineffective righty, and giving the Rangers a second-half shot in the arm.
So if the club should decide that the best choice is McCarthy -- whose new mechanics and early results have impressed thus far, and who has an edge in experience -- so be it. Even if that means series after series of four right-handed starters throwing cut fastballs. Even if that means contention rides on five right arms as of April 5th. And if regular-season history then repeats itself, Rangers fans can party like it's, well, 1999.
[Editor's note: If you're wondering exactly who Josh Garoon is, click here to view the explanatory website announcement, and/or click here to view his bio. Josh, a post-doctorate scholar at Johns Hopkins University in Baltimore, makes his debut appearance in the BBTiA writing lineup today. Welcome aboard, Josh, and try to keep your on-base percentage up.]