The president threw the pitch before the game between the Nationals and the National League Champion Philadelphia Phillies. He was the 13th president to throw a ceremonial first pitch before a Washington Senators or Nationals season opener, according to the White House; President William Howard Taft was the first to do so, on April 14, 1910. (The Senators won that game over the Philadelphia Athletics, 3-0.)
Presidents have delivered Opening Day first pitches 64 times, and Presidents Richard Nixon, Gerald Ford, Ronald Reagan, George H.W. Bush, Bill Clinton, and George W. Bush all took part in the tradition. (Jimmy Carter did not.)
Mr. Obama wore khakis to make the first pitch, and was greeted with a mixture of boos and applause after emerging from the Nationals' dugout. (A mention of George W. Bush, during a montage of former presidents delivering the first pitch, was met with notable derision.) His catcher for the pitch was the Nationals' Ryan Zimmerman, and the president later acknowledged that it was "a little high and outside."