Improper use of YouTube iFrame API

gistfile1.txt

player = new YT.Player( 'introVideo', {
    height: '270',
    width: '480',
    videoId: 'YyCMNdpF6uQ',
    playerVars: {
      rel: 0,
      showinfo: 0
    }
  });


// this works:
player.getDuration();

// this does not work:
player2 = new YT.Player( 'introVideo' );
player2.getDuration();