Prior to the drought, the Red Sox had been one of the most successful professional baseball franchises. They won five of the first fifteen World Series titles, including the first in 1903, more than any other MLB team at the time. During this period, Ruth was a core contributor to the Red Sox's three championships in , , and . Following the sale of Ruth, however, the once lackluster Yankees became one of the most dominant professional sports franchises in North America and set the record for World Series titles by more than twice the amount of any other MLB team. The curse became a focal point of the Yankees–Red Sox rivalry over the years.