According to the analysis of Larry Granillo, the Cubs game watched by Ferris and friends was the 5 June 1985 day game loss to the Atlanta Braves (2-4).
Today, the 29th Anniversary of Ferris Bueller’s Day Off, the Cubs (21-34, at the time of this writing) will be taking on the NY Mets (28-30, at the time of this writing) in a night game at Wrigley. So, no skipping school to watch this one. Also, no singing in parades or driving cars through glass garages.
The Finch and Pea 