Pittsburgh Pirates at Chicago Cubs: Final Score & Recap

The Pittsburgh Pirates erased the Chicago Cubs' 59 percent pre-game win probability advantage and rolled to a 13-7 victory at Wrigley Field on September 20, 2023, finishing the game with the DiamondIQ model's estimate of a Cubs win probability at zero percent. Pittsburgh's offense did the bulk of its damage in two concentrated bursts, plating seven runs in the fourth inning and three more in the sixth, while Chicago's pitching staff absorbed punishment from multiple sources across the lineup.

The decisive sequence came in the top of the fourth, where Joshua Palacios delivered a home run off Jose Cuas that shifted the win probability by 13.0 percentage points in Pittsburgh's favor, followed by a Liover Peguero single off Justin Steele worth 12.8 points and a Jack Suwinski single off Steele adding another 11.1 points. That seven-run frame effectively broke the game open before the Cubs could respond. Chicago did mount a partial rally in the bottom of the fifth when Ian Happ launched a home run off Mitch Keller that represented the game's single largest swing at plus 18.6 percentage points, briefly narrowing the deficit. However, Connor Joe answered in the top of the sixth with a home run off Mark Leiter Jr. that added 11.8 points to Pittsburgh's side, quashing any sustained Chicago momentum.

Among individual performers, Happ finished as the top batter by WPA at plus 17.4 percent with a RE24 of plus 2.6, though his heroics came too late to alter the outcome. Palacios posted plus 16.9 percent WPA and plus 1.6 RE24, while Connor Joe contributed plus 14.7 percent WPA and plus 2.2 RE24 to anchor the Pittsburgh attack. On the mound, Carmen Mlodzinski led all pitchers with a plus 6.4 percent WPA contribution, with Colin Holderman and Brad Boxberger providing steady work behind him to preserve the six-run final margin.