The sabermetric revolution has, over the last 30 years, dramatically changed how we understand baseball. The change started out slowly, and modestly. In the early 1980s, the notions that OBP was important and that ballpark effects could be measured, were considered radical. As recently as 15 years ago, there were few advanced metrics for evaluating fielding. WAR, the statistic that today is broadly viewed as the best measure of overall value, has only been widely used in the last 10 years or so, and has largely pushed out other measures such as runs created or win shares.
Critics of sabermetrics often focus on the inability of quantitative approaches to determine the value of real or imagined parts of the game like leadership, chemistry, team dynamics and the like. These aspects of the game are often overstated and generally hard to measure, but that does not mean they are not real. Determining how these aspects of the game can be measured and how it can be determined which players have these elusive characteristics is the next frontier for sabermetrics.
Quantifying these so called intangibles will not be easy, but it is the next major challenge facing sabermetrics. Measuring individual leadership or teammate skills and team chemistry are separate but related problems. In both cases, the lies in measuring something that is largely a subjective perception. In the current environment, leadership skills and team chemistry are both, for the most part, only as real and significant as teammates and managers think they are. Additionally, both are heavily informed by tautological thinking. Teams that win are thought, inevitably, to have good chemistry. If winning teams get along, that is usually described as being due to team chemistry. If winning teams fight a lot, like the Yankees of the late 1970s, that is viewed as its own kind of chemistry. The subjective and tautological nature of leadership, chemistry and the like make it tempting to dismiss the ideas as nonsensical, but many baseball people are certain they are important, making it hard to dismiss these ideas entirely.
The problem of measuring chemistry or leadership using existing data is that there are many causal directions involved with these concepts. For example, good chemistry may make players put up better numbers, but it also may make teams exceed their pythagorean projections. A good case could be made for either. Bad chemistry, of course, could lead players to put up worse numbers or for a team to play worse than projected. This is made more complicated because there are countless other causes for either of these phenomenon. Players might put up better numbers because of random fluctuation, pitching match ups or a good manager, while a team could outperform its projections because of a good manager, random fluctuation or several other factors. This all makes it difficult to quantify chemistry, leadership and the like, but not impossible.
Efforts to quantify chemistry may seem strange to many, but for years scouts have evaluated the "makeup" of prospects. This refers to the off the field traits of a prospect that includes things like work ethic, character, commitment and the like. This is a good start, but again it is entirely subjective. Finding a way to test those ratings over time, to see which traits in 18-21 year olds are most likely to contribute to success at the big league level, what combinations of players produce good chemistry, or to reevaluate these traits throughout a players career in a way that is repeatable and testable would contribute a great deal to being able to quantify and measure what have heretofore been accepted as intangible and unmeasurable aspects of the game.
Until now, sabermetrics has drawn heavily on disciplines like statistics and advanced mathematics. If the next frontier for sabermetrics is quantifying things like leadership and chemistry, the disciplines to which the next generations of Sabermetricians may have to turn will be be in the social sciences. Social scientists spend their careers studying phenomena that were previously viewed as unquantifiable. The tools they use such as in-depth-interviews, polling based research and testable measurements or evaluations could be very helpful in finding ways to measure weather good chemistry is real, how it can be created and how much of an impact it can have.
In the last decades, big league teams have invested increasing resources in things like proprietary statistical analysis and data management, scouting and talent evaluation, yet chemistry and similar issues are still both largely viewed as important and evaluated using entirely subjective, rarely consistent and often tautological methods. Endeavoring to get more useful data so as to better measure and use ideas like chemistry and leadership seems far-fetched now, but a generation ago pitch-tracking, fielding data and other information we take for granted today would have been hard to imagine.