For many years, this was considered the worst trade in Red Sox history, and was thought to be far more damaging to the Red Sox than the sale of Babe Ruth more than four years later. In his book about the Red Sox-Yankees rivalry, Emperors and Idiots, Mike Vaccaro recalled that for some time, "Red Sox fans shook their head(s) in fury" when recalling the trade. Vaccaro recalled that in the winter of 1919-20, no one knew in 1920 that Ruth would blossom into a superstar. In contrast, Speaker had established himself as "indisputably the best player in the American League" by 1916.
The center field fence at Cleveland's Dunn Field was 460 feet (140 m) from home plate until it was shortened to 420 feet (130 m) in 1920. Even so, Speaker played so shallow in the outfield that he was able to execute six career unassisted double plays at second base, catching low line drives on the run and then beating baserunners to the bag. At least once he was credited as the pivot man in a routine double play. He was often shallow enough to catch pickoff throws at second base. At one point, Speaker's signature move was to come in behind second base on a bunt and make a tag play on a baserunner who had passed the bag.
Speaker guided the 1920 Indians to their first World Series win. In a crucial late season game against the second-place White Sox, Speaker caught a hard line drive hit to deep right-center field by Shoeless Joe Jackson, ending the game. On a dead run, Speaker leaped with both feet off the ground, snaring the ball before crashing into a concrete wall. As he lay unconscious from the impact, Speaker still held the baseball. In the 1920 World Series against Brooklyn, Speaker hit an RBI triple in the deciding game, which the Indians won 3–0. Cleveland's 1920 season was also significant due to the death of Ray Chapman on August 17. Chapman died after being hit in the head by a pitch from Carl Mays. Chapman had been asked about retirement before the season, and he said that he wanted to help Speaker earn Cleveland's first World Series victory before thinking of retirement.