13 games to go. Hard to tell what it's going to take, but they'll just have keep winning. With the Astros and Rangers playing like they are, even winning 8 out of 13 might not be enough.
The series with the Astros will be critical. Losing that series most likely means finishing out of the playoffs. The Astros and Rangers, however, do have a series coming up, and so that series will at least damage one of those two teams.
The Mariners do play a series with the Royals, a .500 team, and a series with the Rockies, the worst team in the majors. But they finish the season against the Dodgers, who are in a tight battle with the Padres for the NL West.
With the Blue Jays pulling away from the Yankees and Red Sox, this battle in the AL West is the most exciting in MLB. I think it's going to go down to the wire, and it's not going to be resolved until the very end.