Kansas City Royals at St. Louis Cardinals: Final Score & Recap

The St. Louis Cardinals outlasted the Kansas City Royals 5-4 in eleven innings on May 15, 2026, at Busch Stadium, with the DiamondIQ model's estimate entering the game at a 70 percent home win probability and closing at 100 percent. The game was scoreless through three innings before both teams traded runs in the fourth, Jordan Walker's home run off Michael Wacha delivering a plus-22.0 percent win-probability swing that gave St. Louis early momentum. After Kansas City drew even and the game stretched into extras, Bobby Witt Jr. provided the decisive blow for the Royals in the top of the tenth with a double off Ryne Stanek that registered a plus-31.3 percent swing, and Lane Thomas's subsequent strikeout against the same pitcher gave back 21.1 percent of that advantage, effectively swinging 52 points of win probability in St. Louis's favor within a single half-inning.

Alec Burleson was the game's most impactful performer by the DiamondIQ model's accounting, finishing at plus-45.5 percent WPA with a plus-1.1 RE24. His single off Lucas Erceg in the bottom of the tenth was the largest single play of the night at plus-51.6 percent, knotting the game and setting the stage for the Cardinals' walk-off. In the eleventh, Yohel Pozo delivered the decisive blow with a single off Steven Cruz worth plus-35.9 percent win probability, finishing with a plus-35.9 percent WPA and plus-0.8 RE24. On the mound, JoJo Romero led St. Louis's relief corps at plus-14.5 percent WPA, followed by Riley O'Brien at plus-13.5 percent and Nick Mears at plus-10.9 percent, as the Cardinals bullpen ultimately held together long enough for the offense to finish the job in eleven.