MLB Recap · May 18, 2026

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

BOS3
Final
KC1

Line Score

Team123456789RHE
BOS000002100390
KC000000100160

The Story

The Boston Red Sox silenced Kauffman Stadium on May 18, 2026, defeating the Kansas City Royals 3-1 behind a pair of late-inning offensive bursts and stout pitching down the stretch. The game was scoreless through five innings before Boston broke it open, and the DiamondIQ model's estimate, which opened with Kansas City holding a 53% pre-game win probability, closed at 0% in favor of the Red Sox by the final out.

The decisive moment came in the top of the sixth when Willson Contreras drove a home run off Seth Lugo, a swing that shifted win probability by 23.5 points in Boston's favor and gave the Red Sox a lead they would not relinquish. Kansas City responded with a run in the bottom of the seventh on a Jac Caglianone double off Sonny Gray that moved the needle 16.2 points toward the Royals, briefly tightening the contest. However, Justin Slaten answered by striking out Isaac Collins to strand the threat, a strikeout that swung win probability 7.4 points back toward Boston, and Garrett Whitlock followed by inducing a Salvador Perez groundout in the eighth that represented an 8.8-point swing in Boston's direction. Aroldis Chapman closed out the ninth, with a Collins groundout in the final frame actually reflecting a 14.4-point positive swing for Boston as the Royals exhausted their final opportunity.

Caglianone led all batters with a WPA of plus-18.4 and an RE24 of plus-1.8, while Contreras finished just behind at plus-18.3 WPA and plus-1.0 RE24, making the two the central offensive figures despite playing for opposite sides. On the mound, Slaten paced Boston's pitching staff with a plus-19.0 WPA contribution, with Whitlock adding plus-13.3 and Sonny Gray contributing plus-8.9 in a losing effort for Kansas City.

Analysis generated by DiamondIQ's model.

Win Probability

755025BOS bats firstFinalKC win %BOS win %
DiamondIQ model home win probability across the game (pre-game 53.1% → final 0%).

Biggest Plays by Win-Probability Added

Willson Contreras Home Run
Top 6th · off Seth Lugo
+23.5%
Jac Caglianone Double
Bot 7th · off Sonny Gray
+16.2%
Isaac Collins Groundout
Bot 9th · off Aroldis Chapman
+14.4%
Salvador Perez Groundout
Bot 8th · off Garrett Whitlock
-8.8%
Isaac Collins Strikeout
Bot 7th · off Justin Slaten
-7.4%

Top Batters by WPA

Jac Caglianone+18.4%+1.8 RE24
Willson Contreras+18.3%+1.0 RE24
Mickey Gasper+5.7%+0.3 RE24

Top Pitchers by WPA

Full box score, pitch data, and the play-by-play timeline
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