On May 29, 2010, Roy Halladay of the Philadelphia Phillies pitched the twentieth perfect game in Major League Baseball history, against the Florida Marlins in Miami. He retired all 27 batters, striking out 11. This was the first time in the modern era that two pitchers (Dallas Braden of the Oakland Athletics being the other) threw perfect games in the same month and that multiple perfect games had been achieved in the same season.
Roy Halladay's rookie season in 1999 featured 3.92 ERA in 149 1⁄3 innings for the Toronto Blue Jays. In his second year, he finished with an ERA of 10.64, the worst by any pitcher who tossed 50 innings or more. He improved from this dismal performance, and he played 12 seasons for the Toronto Blue Jays, in which time he averaged 17 wins per season, made six all-star teams and, in 2003, won a Cy Young Award. In his second major league start, on September 27, 1998, he retired 26 Detroit Tigers in a row before he gave up a home run to Bobby Higginson.
On Opening Day, Halladay pitched seven innings while giving up a run against the Washington Nationals in his first game with the Phillies. He had nine strikeouts and allowed six hits. He also drove in his second career RBI and earned his first win of the season. He followed this start with a complete game on April 11 against the Houston Astros, giving up one unearned run while striking out eight and not giving up any walks in the Phillies' 2–1 victory.
Halladay pitched his first shutout in the National League, against the Atlanta Braves on April 21, becoming the first pitcher to reach four wins in the 2010 season. On May 1, Halladay pitched his second shutout of the season, limiting division rival New York Mets to three hits and striking out six.