Already much has been made about this being the first all-wild-card World Series. Although it may be true that this is the first time that two teams designated as "Wild Cards" have met in the fall classic, this is not the first time that two teams that did not have the best record in their division or league have battled for the crown.
In the strike-interrupted season of 1981, an artifice was imposed to acknowledge those teams that led their division as of the strike date (June 12) and to re-line the pockets of the fat cats who ran baseball, i.e., the split season. The teams that were leading as of the strike were automatically accorded a playoff berth when play resumed. They would meet the second-half winners, the division leaders from that point forward, at the end of the year in a division series.
If one team won both "halves", a wild card would face the division winner. If I remember correctly, the wild card team was the second place team for the entire year not just the second half. This was a point of contention for the Kansas City Royals who finished fifth, 12 games behind first-place Oakland in the first half. They were battling the A's down the second-half stretch, when it was confirmed by commissioner Bowie Kuhn that they would have to win the division to qualify for the playoffs given that their first-half record was so poor. (Or did I dream that). Anyway, the Royals clinched the second half by two games and the wild card was never invoked since none of the other first-half winners finished higher than third in the second half.
The two league champions were the Dodgers and the Yankees, and they met in a repeat of their 1977-'78 Series. Both teams were first-half champs who fell to fourth and seventh place, respectively, in the second half.
The Dodgers won their first-half title by one-half game over the Reds. The Reds lost the second half to the Astros by 1.5 games and finished with the best record in baseball (66-42 or 99-63 in a 162-game schedule) but famously failed to make the playoffs. The Dodgers were second overall, four games behind Cincinnati.
The Yankees led a strong AL East division at the strike-six of the seven teams were over .500 and just 4 games separated the top 5 teams-, but fell to sixth with no incentive in the second, one game below .500, in the second half. Overall, New York was third behind second-half champs Milwaukee (yes, the were the AL once), and only 2.5 games separated the top 5 teams.
When the Yankees met the Dodgers in the World Series, which LA won four games to two, there was a third-place team versus a second-place team overall.
By the way, the genesis of the wild card was in the odd year of 1892. In that year the National League had just swallowed its old partner/rival the American Association and like a snake swallowing its prey had ballooned to twelve teams. Their postseason series, the Temple Cup, which had been a contest between each league's champ, now had to be revised to have two NL-only representatives. Their resolution was a split-season with each half's champ meeting in the postseason. The first-half and overall champs, the Boston Beaneaters, defeated the second-half champions, the Cleveland Spiders, for the Cup.
This format was a failure and the Temple Cup series was not even played in 1893. But the series was revived in 1894 and ran until the 1897 season. In its last rendition, the top two finishers overall would meet in the Temple Cup series. A team would finally win the actual cup after three successive championships over three years. The series were never highly regarded, and no one ever did win that dang cup. But in 1894 and '95 the first two second-place finishers, the New York Giants and the Cleveland Spiders, won and became the first two wild card champs.