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Most grand slam home runs hit in a Major League Baseball season

Most grand slam home runs hit in a Major League Baseball season
Who
Don Mattingly, Travis Hafner
Where
United States
When
1987
The Major League Baseball (MLB) record for most grand slam home runs hit in a season is six by Travis Hafner (USA) playing for the Cleveland Indians (USA) in 2006 and Don Mattingly (USA) for the New York Yankees in 1987. A grand slam is a home run hit with the bases loaded.