To ease the stress on his deteriorating knees, Piazza began to split his time between catching and playing first base during the 2004 season, an experiment which was abandoned before the end of the season because of Piazza's defensive deficiencies. Although recognized as a great hitter, Piazza has had some notable defensive accomplishments. Among them, Piazza caught two no-hitters thrown by Ramón Martínez and Hideo Nomo while playing with the Dodgers. Nomo's was particularly impressive because it happened at Coors Field, notorious for being a hitter-friendly ballpark. Additionally, Piazza's .997 fielding percentage was tops among NL catchers in 2000.