The 2012 World Series is showcasing two teams that have never played each other in the postseason.  The American League champion Detroit Tigers take on the National League champion San Francisco Giants in Game One of the Fall Classic Wednesday night at AT&T Park.  The Tigers swept the New York Yankees in four games to capture the AL pennant, while the Giants rallied from a three-games-to-one deficit to beat the St. Louis Cardinals and claim the NL title.  Detroit sends reigning AL Cy Young and MVP winner Justin Verlander to the mound in Game One, while the Giants counter with left-hander Barry Zito.  This is the eleventh trip to the World Series for Detroit, which was last in the Fall Classic in 2006 but hasn't won it since 1984.  It's the 19th World Series for the Giants, who beat the Texas Rangers to win the title in 2010.  San Francisco has home-field advantage in the best-of-seven series after the National League won the All-Star Game in July.