I don't have a whole lot to say about the life of Marvin Miller, who died on Tuesday at age 95, other than that Miller might be the most significant figure in sports law; in fact, by introducing true labor law in sports, he arguably invented the field. Ironic, given that he was not a lawyer.
Instead, have a look at this piece by Tim Marchman in Slate, which argues that Miller achieved success by taking incremental steps, waiting for the right moment to attack the big issues (he was union head for almost a decade before the reserve clause fell, although he recognized that as a winning issue immediately), and being fortunate enough to go up against generally incompetent people on the other side of the table.