Intangibles. It seems that players who have them never get all the credit they deserve, and that has always bothered me. Intangibles are the reasons that the Red Sox drafted Dustin Pedroia over Kurt Suzuki. "We went with our hearts and drafted Dustin," they said. Did they just get lucky, or is there more to it? I propose that the particular intangible of being a team leader is measureable, if you define it as a player whose presence on the field elevates his teammates' performance.
How can we measure this elevation? I think we should look at the times when the team leader is absent, either due to injury or days off, and note his teammates' stats (say for example, wRC+, OPS, WAR, FIP) during these time periods. Then we can compare those to the teammates' stats in the two weeks both before and after the leader's absence. My hypothesis is that the differences, on average, will be noticeable and greater than chance. Perhaps the analysts at BtBS could run the numbers for me on Pedroia as team leader to see if this actually pans out. And if not Pedroia, are there other team leaders out there who do fit the bill?