 The rivalry is often a heated subject of conversation , especially in the home region of both teams , the Northeastern United States . Until the 2014 season , every season 's postseason had featured one or both of the AL East rivals since the inception of the wild card format and the resultant additional Division Series ; they have faced each other in the AL Championship Series three times . The Yankees won twice , in 1999 and 2003 ; while the Red Sox won in 2004 . In addition , the teams have twice met in the last regular @-@ season series of a season to decide the league title , in 1904 ( when the Red Sox won ) and 1949 ( when the Yankees won ) . 
