The Chicago Cubs defeated the Seattle Mariners 7-4 at Sloan Park on March 12, 2026, in a game the DiamondIQ model's estimate opened as a modest home-side lean at 54% and closed at 100% in Chicago's favor. The Cubs built their lead incrementally, scoring twice in the third inning and once in the fifth before a four-run seventh inning put the game away. Seattle mounted a three-run rally in the eighth, but the damage was already done.
The decisive sequence came in the bottom of the third, where Ian Happ's double off Emerson Hancock produced the game's single largest win-probability swing, adding 20.2 percentage points in Chicago's favor. BJ Murray added to the inning with a double of his own off Hancock, contributing another plus-6.8 percentage points, though Nico Hoerner's strikeout against Hancock cost the Cubs 7.1 points of win probability and left runners stranded. In the top of the fourth, Andrew Knizner's forceout off Grayson Moore swung 9.1 percentage points back toward Seattle, briefly slowing Chicago's momentum before the Cubs reasserted control. Chas McCormick's home run off Josh Simpson in the seventh added 7.4 percentage points and effectively salted the game away.
Happ finished as the game's top offensive performer by WPA at plus-17.6, accompanied by a plus-1.5 RE24, reflecting the run-environment value of his contributions. Michael Busch added plus-9.8 WPA and Brendan Donovan contributed plus-7.6 WPA to round out Chicago's most impactful bats. On the pitching side, Jack Neely led Cubs relievers at plus-7.2 WPA, with Corbin Martin and Phil Maton each adding plus-6.4 WPA in holding Seattle's late surge to three inconsequential runs in the eighth.
Analysis generated by DiamondIQ's model.