With the Athletics losing 7-5 to the Mariners, the Red Sox have clinched the best record in the AL and thus home-field advantage throughout the playoffs. The AL beat the NL in the All-Star Game to clinch home-field advantage in the World Series.
The Red Sox will have the best record in the league regardless of what happens in their games on Saturday and Sunday. They will host the AL wild-card winner -- that race is still very, very much up in the air -- at Fenway Park next Friday. The Athletics (AL West winner) will host the Tigers (AL Central winner) in Oakland in the other ALDS.
Home-field advantage is a big deal to the Red Sox given the uniqueness of Fenway Park, but they have winning records both at home (53-28, .654) and on the road (44-35, .557) this season. Plus it's nice to know where they'll be spending the next week, of course.
The Rays, Rangers and Indians are all still in the mix for the two AL wild-card spots. There could be a two- or three-team tie depending on the outcome of Sunday's games.