Currently, The Yankees Alex Rodriguez and the Royals Yuniesky Betancourt are the major league leaders with three grand slams each in 2010.
Through the 2013 season, there were 6452 grand slams hit in baseball history. The most grand slams in a season happened in the year 2000 when 176 grand slams were hit.
Alex Rodriguez has hit three grand slams during the 2010 season.
Lou Gherig
two grand slams
Lou Gehrig with 23
Chase Utley
lou gherig
McCovey
phillies
Andre ethier has hit 2 grand slams so far
6 Grand Slams = Don Mattingly(1987New YorkYankees),Travis Hafner(2006 Cleveland Indians)
Mariano Rivera has given up 4 grand slams in his career. The most current grand slam yielded by Mariano was on May 16, 2010, hit by Jason Kubel of the Minnesota Twins.