Kansas City Royals at Boston Red Sox: Final Score & Recap

The Boston Red Sox defeated the Kansas City Royals 5-1 at Fenway Park on September 12, 2026, a result the DiamondIQ model's estimate anticipated from the outset with a 64 percent pre-game home win probability that climbed steadily to 100 percent by the final out. Boston's offense was quiet through three innings but began to pull away in the fourth when Adley Rutschman delivered a single off Randy Dobnak that added 9.5 percent to Boston's win probability, giving the Red Sox a 1-0 lead. The decisive blow came in the bottom of the sixth, when Wilyer Abreu doubled off Anthony Gose for the single biggest win-probability swing of the game, a +24.7 percent shift that effectively put the contest out of reach and pushed Boston's cushion to a commanding position.

Kansas City managed its lone moment of life in the top of the sixth, when Carter Jensen launched a home run off Ranger Suarez to cut into the deficit, a swing that moved the Royals' win probability by 13.8 percent, though it proved too little against Boston's accumulating advantage. Suarez settled after that, and a Matthew Lugo strikeout in the seventh swung win probability another 4.3 percent back toward Boston, negating Michael Massey's subsequent single that had briefly offered Kansas City a flicker of hope. The Royals finished with five hits and no errors while Boston collected ten hits and committed one error across the final 5-1 margin.

Wilyer Abreu finished as the game's top performer by WPA at plus 20.3 percent with a RE24 of plus 1.1, while Carter Jensen's plus 11.4 percent WPA led Kansas City's contributors despite the loss. On the mound, Randy Dobnak paced all pitchers with a plus 17.4 percent WPA contribution, and Ranger Suarez added plus 16.1 percent for Boston despite surrendering the Jensen home run, as his work suppressing further Kansas City scoring proved essential to preserving the comfortable final margin.