The strength of the group is the strength of the leaders. — Vince Lombardi



The memory remains vivid for Ben Cherington. In spring training of 2013, when he was the Red Sox general manager, Cherington was in line in the players’ lunchroom after a morning workout in Fort Myers, Fla. He could not help but overhear a nearby discussion.



It was loud.



“There were four players at a table, a couple veterans, a couple younger players, still in workout gear, and they were having this conversation about a bunt defence drill that they had done that day,” he recalled. “It was a loud and passionate debate over how that drill went, how it could be better, what they needed to do to make it better. And ultimately one of the players at the table said, ‘If we want to win, we need to be better at that.’”



Consider the import of an American League team practising bunt defence in February. The drill in question, and the...