As regular readers of this blog are aware, Jim has been practicing some very good economics in his recent posts while I have been silent. But I turn now to an important and often overlooked issue. While debates have raged over whether the country is shifting to the left or to the right, most of us have overlooked a dramatic rise in the number of citizens who go either left or right, depending on the circumstances. I refer not to bi-partisans or independents but bi-dexterous batters, a k a switch hitters. This post is a progress (or lack thereof) report on a work-in-progress on the boom that occurred in this population during the latter half of the 20th century.
While working on a baseball book that addressed questions that my children and those of my friends asked including, “why do some batters switch-hit?” I sensed that there seem to be a lot more switch hitters today than in my youth. I often find that recollections of my youth do not survive encounters with data but as the graphic (click on to enlarge) illustrates, the population of major league batters swinging from both sides increased from two or three percent in the 1950s to over 20 percent in the late 1980s and 1990s before settling back down to around 15 percent in this decade.
Having confirmed that the phenomenon was real, I began to explore why this dramatic shift took place. I scanned the literature and was unable to find a research paper on the topic. Lee Sinin, the extraordinarily knowledgeable proprietor of The Complete Baseball Encyclopedia, indicated that he was also unaware of any research into the topic. So, with dreams of accolades from the Society of American Baseball Research (SABR), I decided to look a little deeper.
Since I was looking at the percentage of switch hitters, I didn’t expect there to be a strong direct relationship between expansion and switch-hitting. But it is conceivable that expansion’s temporary dilution of hitting and pitching talent might have in some way encouraged switch-hitting. The vertical lines drawn on the graph indicate expansion years and the number of teams added. Interestingly, the line does seem to accelerate following the early 1960s expansion, then increases in 22 of the next 31 years until the 1993 NL expansion, then fluctuates around 19 to 20 percent until just before the 1998 expansion, and has declined in 9 of the 11 years since then, currently sitting around 15 percent. What accounts for this pattern?
I have been unable to identify a testable hypothesis that would explain the pattern in terms of pitcher and/or hitter talent dilution related to expansion. One obvious problem with linking the phenomenon to expansion is that most (but not all) switch hitters learn the art in their youth typically, as in the cases of Mickey Mantle and Pete Rose, prompted by their father. This means that new switch hitters would have to be in the pipeline somewhere around eight to ten years before they made it to the majors.
The anecdotal evidence about fathers teaching sons to switch hit does suggest a sort of halo or role model effect that might fit with the timing of the first upturn. It is possible that Mantle’s early success may have inspired some ambitious young players to become switch hitters in their early to mid teens and that cohort began appearing in the early 1960s. I plan to explore that possibility by identifying what is available about the background and motivation of the players in that first wave of new switch hitters reaching the majors in the early 1960s. Other possible areas of inquiry include the suggestion by Dekkers Davidson that I examine the possible influence of artificial turf which might have encouraged weaker right handed hitters to gain a step down the line against right-hand pitching. Dekkers also suggested it might be worthwhile examining the possible effect of the DH by exploring comparative AL and NL data.
In the meantime I am posting the basic data and inviting comments and suggestions from our freinds.
Posted by Bob