Two answers required. Through 2016, two of the four biggest plays in baseball history (by championship probability added) both occurred in Game 7 of the 1960 World Series. Name both the backup catcher whose three-run homer in the eighth inning took Pittsburgh from 30% to 93% (biggest play ever!), and the second baseman whose walkoff homer an inning later was technically a lower WPA (37%) but far better remembered.
Hal Smith; Bill Mazeroski