When it comes to the St. Louis Cardinals, run differential isn't always the final word on success—and the numbers prove it. You might be surprised to learn that teams with a negative run differential have actually made the postseason. While we're not predicting the 2026 Cardinals will finish in the red, we're also not guaranteeing a playoff spot. So, let's take a trip back to 1981 and see how this stat has played out in Cardinals history.

In 1981, the Cardinals outperformed their Pythagorean record—the expected win total based on runs scored versus runs allowed—by just three games, thanks to a positive run differential. But by 1983, even with a positive differential, they finished four games below .500. Fast forward to 1984: St. Louis sat six games above .500, but their run differential was barely above zero, suggesting they were lucky to be there. Then came 1986, when the Cardinals perfectly matched their Pythagorean record, finishing 79-82 with a -10 run differential.

The 1991 squad overachieved slightly, finishing a few games over .500 when the numbers said they should have been exactly at .500. And who could forget the 2006 Cardinals? They posted a modest +19 run differential but barely outperformed their Pythagorean record—and went on to win the World Series. It's rare, but it happens. Could a team with a negative run differential ever pull off that kind of magic?

The 2007 Cardinals might have the answer—sort of. That team finished with a brutal -104 run differential, but surprisingly, the Pythagorean formula suggests they should have been even worse, about 20 games under .500. Instead, they finished just six games under. So maybe they never really paid the piper! That team simply didn't care about the numbers.

By 2008, the Cardinals were back to nailing their Pythagorean record, just like the 1986 team. They won 86 games, finishing 10 games over .500. In 2010, however, they underperformed relative to their +95 run differential. The numbers said they should have won 91 games, but they only managed 86—still 10 games over, though. And the incredible 2011 team? They barely overperformed their Pythagorean mark, but we all know how that season ended.

So, what does run differential really mean for the Cardinals? It's a useful tool, but as history shows, it's never the whole story. Sometimes, heart and hustle matter more than the math.