Boston was a dominant team in the new league, defeating the Pittsburgh Pirates<span> in the first </span>World Series<span> in </span>1903<span> and winning four more championships by </span>1918<span>. However, they then went into one of the longest championship </span>droughts<span> in baseball history, dubbed the "</span>Curse of the Bambino<span>" after its alleged beginning with the Red Sox' sale of </span>Babe Ruth<span> to the rival </span>New York Yankees<span> two years after their world championship in 1918, an 86-year wait before the team's sixth World Championship in </span>2004<span>.</span>
