For decades, statheads have called for teams to turn back the clock by reverting to four-man pitching rotations from the five-man ones that first took hold at the major league level in the early 1970s and advanced throughout the game over the ensuing decade. Since then, the occasional team has briefly experimented with four starters, and Tony La Russa even went to three for about a week with Oakland in 1993. Those changes were short-lived, however. So it was difficult to take seriously Tuesday’s announcement from Rockies manager Jim Tracy that his team was not only switching to a four-man rotation, but that it would do so while keeping its starters on a 75-pitch limit.