 The seating configuration was significantly altered, most notably by tearing out most of the outfield seating except for parts of the lower decks in left and right fields, to more closely resemble the original design from the park's first 15 years.The finished product in 1998 was a retro-modern ballpark.The same year, when Chase Field opened for the expansion Arizona Diamondbacks, it incorporated a retractable roof and a swimming pool — elements that did not exist in jewel-box ballparks.