American League: Boston Red Sox (75-51) - Fifth World Series (won in 1903, 1912, 1915, 1916)
National League: Chicago Cubs (84-45) - Fifth World Series (won in 1907, 1908)
It's commonly known that Babe Ruth was an all-star caliber pitcher before he became known as the game's greatest slugger. What isn't as well known is that there was really only one season where he was both. In 1918, with the Red Sox roster devastated by old age and World War I enlistments, Boston manager Ed Barrow had little choice but to use Ruth in both roles. Ruth started 20 games for Boston, going 13-7 with a typically wonderful ERA. When he wasn't pitching, Ruth was playing left field, the first time in his career he had seen extended action in the outfield, and he didn't disappoint. He hit an American League-high 11 home runs (out of only 15 the Red Sox hit as a team) and led the team in doubles, runs batted in, and batting average.
With such a powerful, versatile player in their midst, it didn't really matter that the rest of the Red Sox were ho-hum at best. Ruth won the American League pennant basically by himself, and his presence in the lineup made the Red Sox the easy favorites over the Cubs in the World Series, which was played the first week of September as baseball was forced to shut down the season early for World War I.
Entering the series, though, Boston manager Ed Barrow made a curious decision. He announced that Ruth would appear in the series only as a pitcher, not as an outfielder. Barrow said his reason was that the Cubs were going to use only left-handed pitchers in the series, but that excuse rang as hallow then as it does now. There was no good reason for Barrow to deprive himself of his team's best weapon. But he did it anyway. (Even more curiously, it wasn't the first time that had happened. Ruth got only one at bat in Boston's 1915 World Series victory and only started one game in the 1916 series. Makes you wonder what the Boston management was thinking).
Ruth showed just how dominant he could be on the mound in Game 1 by shutting out the Cubs, continuing his personal World Series scoreless innings steak to 22. The Red Sox needed every bit of his brilliance, too, as they could only manage 1 run off Hippo Vaughn, who won the National League's pitching triple crown in 1918. But after his shutout in Game 1, Ruth retreated to Boston's bench, not budging as his team split games 2 and 3, scoring only three total runs in the process.
Barrow's decision was justified a little bit by the surprising good play by Ruth's replacement in left field, George Whiteman. Even though he was 35 years old, Whiteman had played only 15 career Major League games before the 1918 season began, but he handled himself well as Ruth's backup in the outfield. Starting all six games of the series instead of the two or three he probably should have started, Whiteman surprised in the series, getting several clutch hits and making two huge defensive plays - a running catch in the fourth inning of Game 3 that saved at least one run, and a stumbling catch in the eight inning of Game 6 to preserve a one-run lead. But it's not like Ruth couldn't have made those catches - he was still a lean, muscular athlete in 1918, nothing close to the pot-bellied slugger that has become his trademark. And the Red Sox only scored nine runs in the series, so you imagine he could have added at least a couple more to that tally.
But alas, the Red Sox didn't need him. They had a 2-1 series lead when he took the mound again in Game 4, and though he finally gave up a run - ending his scoreless innings streak at 29 innings - he hit a two-run triple that helped the Red Sox to a 3-2 win and a 3-1 series lead. He then became a spectator again, watching as they were shut out in Game 5, then as they won Game 6 2-1. He was on the field at the end of Game 6, but as a defensive replacement.
It didn't make sense, but it worked, as the Red Sox celebrated their championship, their fifth in the first 15 years of the World Series. It started to fall apart after that. Ruth requested to play just one position in 1919 - either pitcher or outfield - and the Red Sox picked outfield. He responded with a then-Major League record 29 home runs, then was promptly sold to the Yankees. After selling Ruth, Barrow followed him to New York, taking over as general manager of the Yankees and eventually building baseball's first great dynasty. Meanwhile, after beating the Cubs in 1918, the Red Sox waited 88 years to win their next title.
Ruth was the MVP. Two complete-game wins, plus the two-run triple in Game 4. Looking back, it almost looks like he was the only player on the field who knew how to play the game. Imagine if he had played every game in the series.
Ruth batted sixth in Game 4, the first and only time a pitcher has batted anywhere but 9th in a World Series game.
(Home team shaded; winners in Bold)
I'm ranking all the World Series, from worst to best. Here are the ones I've done so far:
26. 1918 - Boston (A) def. Chicago (N) 4-2
27. 1988 - Los Angeles (N) def. Oakland (A) 4-1
28. 1946 - St. Louis (N) def. Boston (A) 4-3
29. 1925 - Pittsburgh (N) def. Washington (A) 4-3