Among several American League clubs vying for the postseason, the Astros and Orioles begin a key four-game series Thursday night at Camden Yards. The Orioles, who dropped to third place in the AL East for the first time this season with Wednesday's 8-1 loss to Boston, currently hold the final AL Wild Card spot. The Astros enter the series 5 1/2 games back of Baltimore in the Wild Card race, but they will have a chance to cut into the deficit this weekend.