SAN FRANCISCO — We really should know better by now, all of us. Some teams get to the postseason and fold. Some teams get there, shake off their regular-season woes and defy expectation. If you don't know which one the San Francisco Giants are, they've got two World Series rings to show you from the past four years. Those rings — even though the Giants have them, making their club the closest thing to a dynasty we've seen in recent years — still don't seem to buy the Giants much respect. Here they are in the postseason again. And here they are, underdogs again. "Always," says ace pitcher Madison Bumgarner, whose beer-chugging celebrations are becoming a postseason treasure.