The Cubs and White Sox have been in the postseason in the same year just three times. That might change in 2026.

The Chicago Cubs are celebrating their 150th anniversary this year. The Chicago White Sox, charter members of the American League in 1901, are in their 126th season.

That’s a lot of baseball and a lot of history. And in the World Series era of Major League Baseball the two Chicago teams have played in October in the same year in just three of the 121 seasons we’ve had postseason baseball. Those years are 1903 to 2025, with these exceptions: 1904 (no World Series because manager John McGraw of the Giants was being pigheaded and refused to play the AL champion A’s) and 1994, when the postseason was cancelled due to a players’ strike.

In addition to having been in the postseason together just three times, the Cubs were often awful when the Sox were in the postseason and vice versa. Consider this article a slice of Chicago baseball history.

I’ve made two tables to show that to you. First, here are the 22 Cubs postseason years:

While the Cubs were good in the 1920s, 1930s and 1940s, the Sox were pretty bad for almost that entire era. Here’s the chart for the 11 White Sox postseason years:

Apart from the three matching postseason years, the Cubs were also generally pretty bad when the Sox played in October, most recently in 2021 when the Sox appeared to have a team that could make the playoffs in multiple years and the Cubs had their big selloff. That postseason run for the Sox obviously didn’t happen and they have been terrible since then… until this year.

And that brings us back to 2026, where we come out of the All-Star break with both Chicago MLB teams in postseason position. The Cubs are currently in the first NL Wild Card spot, with a real chance of winning the NL Central, and the Sox are in a virtual tie with the Guardians for the AL Central lead, both teams at four games over .500. In fact, only five of the 15 AL teams are over .500 at this time — besides those two, the Rays and Yankees are battling for the AL East, and the Rangers, currently two games over .500, lead the AL West.

Of the three seasons where both Chicago teams made the postseason, one of them (2020) was the shortened pandemic season and should be taken with some grains of salt. Both teams were bounced out of that year’s 16-team postseason in the first round, the Cubs swept by the Marlins and the Sox losing a Wild Card series 2-1 to the A’s.

In 2008, the Cubs appeared possibly headed to the World Series with the best record in the NL (97-64) and breakage of their WS drought on its 100th anniversary. But they were rudely dispatched by the 84-78 Dodgers, swept in a division series. Meanwhile, the Sox had to win three straight games against three different teams just to get in — the final regular-season game vs. Cleveland, then a rainout makeup game against Detroit, then a divisional tiebreaker with Minnesota. After that they got bounced in the division series by the eventual AL champion Rays.

The other one, of course, was 120 years ago, when the Cubs won a still-MLB record 116 games and were expected to demolish the 93-win White Sox. But the “Hitless Wonders” White Sox, who had the best pitching staff in the American League, outscored the Cubs 22-18 in winning the World Series four games to two.

One other year in which there was hope in Chicago that both teams would make the postseason was 1977, when the Cubs got off to a 47-22 start, only to collapse and finish at .500. The Sox, who roared into first place at midseason on the strength of a 22-6 July, also faded and finished 92-70. Both teams were in first place as late as Aug. 6. This year? “As always, we await developments.”

As we return to the present day, it does seem as if 2026 will be the fourth time both Chicago MLB teams will be in the postseason and first in 18 years. They could, conceivably, both go into the October tournament as division champions with first-round byes. Who knows? 118 years after their only World Series meeting, could the Cubs and Sox play in October this year? Now that would likely grab a lot of nationwide attention.