Pittsburgh Pirates at Chicago Cubs: Final Score & Recap

The Pittsburgh Pirates erased a road underdog role to defeat the Chicago Cubs 8-6 at Wrigley Field on September 21, 2023, handing Chicago a loss despite the DiamondIQ model's pre-game estimate giving the home side a 59 percent chance of winning. Pittsburgh scored in four separate frames, building leads in the third, fifth, and ninth innings while the Cubs were unable to sustain a late charge, as the model's final win probability settled at zero percent for Chicago.

The game's decisive sequence began in the third inning when Miguel Andujar drove a double off Kyle Hendricks, a hit that shifted win probability 19.1 percent in Pittsburgh's favor and laid the foundation for what would become his game-high plus-24.8 percent WPA and plus-2.5 RE24 line. The eighth inning proved to be the fulcrum of the contest. Ryan Borucki retired Ian Happ on a flyout that swung win probability 12.9 percent against Chicago, a pivotal out that stalled a Cubs rally. Pittsburgh then added to its lead in the top of the ninth when Joshua Palacios launched a home run off Julian Merryweather, a swing worth plus-14.2 percent in win probability that effectively sealed the outcome. Chicago's attempts to respond were extinguished in the bottom of the ninth, where Nico Hoerner's groundout off Colin Holderman had earlier added 16.1 percent for the Cubs in the eighth, and Yan Gomes's flyout off David Bednar in the ninth added 14.4 percent, both ultimately falling short as Pittsburgh's bullpen held firm.

Johan Oviedo was the standout performer on the mound, finishing with a plus-31.9 percent WPA that led all pitchers and anchored Pittsburgh's pitching effort. Ryan Borucki contributed plus-12.9 percent WPA in relief, and Drew Smyly added plus-2.1 percent. Nico Hoerner finished as the top Cubs batter despite the loss, posting plus-22.9 percent WPA and plus-2.1 RE24, though his team's two errors in a game that ended 8-6 proved costly against a Pirates side that committed none across eleven hits.