SAN FRANCISCO -- The dream started when he was drafted by the Giants seven years ago, and on Sept. 29, 2015, Mac Williamson took the field at Oracle Park, which then was known by different name, for the first time. He has played left field and right at the park, hit homers there, gone through highs and lows.Williamson has an appreciation for the ballpark, how beautiful and unique it is. But he also really would like to change part of it.