Kansas City Royals at Seattle Mariners: Final Score & Recap

The Kansas City Royals took a 4-1 decision over the Seattle Mariners at T-Mobile Park on May 3, 2026, completing a win that the DiamondIQ model's estimate had pegged at just 44 percent before first pitch given Seattle's home-field edge. Kansas City broke through in the fourth inning against Luis Castillo, doing damage not through hard contact but through Castillo's inability to put hitters away. A walk to Carter Jensen, worth +9.7 percent in win probability, and a hit by pitch to Salvador Perez, adding another +9.2 percent, loaded the bases and created the conditions for a three-run frame that shifted the game's center of gravity firmly toward the visitors. Isaac Collins added an insurance run in the sixth with a double off Castillo that swung win probability another +11.3 percent, pushing Kansas City's cushion to four runs and effectively sealing matters.

The pitching performance from Kris Bubic was the decisive factor in preventing Seattle from mounting any answer. Bubic contributed +26.3 percent in win probability on the night, the single largest contribution by any player in the game, and he neutralized the Mariners lineup at its most dangerous moments. His most consequential sequence came when Randy Arozarena grounded into a double play in the bottom of the sixth, a swing of -10.1 percent against Seattle that erased a potential rally in one efficient play. John Schreiber and Alex Hoppe added +3.5 and +2.1 percent respectively in relief, closing out a game that saw Seattle manage only four hits and commit one error against a Kansas City staff that never allowed the home side to find any sustained offensive footing. Daniel Lynch IV recorded the final out by striking out Cole Young in the ninth, a play worth +6.3 percent as the Mariners' final threat evaporated.