A look at what's happening all around the major leagues Saturday: --- MARQUEE MATCHUP San Francisco's Madison Bumgarner, the MVP of the World Series, and San Diego's James Shields, who lost twice to MadBum in the Fall Classic, are scheduled to start against each other. ''It's hard to be believe it's happening already, this early in the season,'' Giants manager Bruce Bochy said. Shields signed with San Diego in the offseason.