Rivalries can be overwrought. Baseball’s grind and a new balanced schedule tend to dilute the drama of midsummer matchups. But last year offered a reminder of the impact winning a season series against a division opponent can have.

Since the Trade Deadline, the Yankees are 0-5, with three losses being connected in some way to a bullpen meltdown after reinforcing it at the deadline. More concerning: the Red Sox have not only leapfrogged them in the standings,