The San Francisco Giants have their ace, Madison Bumgarner, positioned to pitch twice as they embark on what, for all intents and purposes, is a must-sweep homestand when they open a four-game series against the visiting Pittsburgh Pirates on Monday night. With just three weeks remaining in the regular season, the Giants find themselves with the unenviable task of having to pass five teams and make up 7 1/2 games in order to earn the second wild-card playoff berth in the National League. San Francisco does have an advantage over the others, however.