Patty Mills isn't the first player that comes to mind as a key for Game 3 of the NBA Finals. In fact, if there were a list of 10 such players from the Miami Heat and San Antonio Spurs, Mills still might not make anyone's cut.

As a Spurs role player, though, Mills is far more important than most realize in preventing LeBron James from winning his third straight title. Mills's value to San Antonio's playing style has never been so clear. Now, there is empirical evidence supporting one of the theories for the Spurs' remarkable...