Unfortunately, the most recent data I could find was for the 2008 MLB season. In 2008, 124 grand slams were hit (72 in the AL and 52 in the NL) in 2428 total games for an average of 1 grand slam every 19.58 games.
The most grand slams hit in an MLB season is 176 (89 in the AL and 87 in the NL) in 2429 games in the 2000 season for an average of 1 grand slam every 13.80 games.
yes there was a walkoff grand slam this year
Lou Gehrig hit 23 career grand slam home runs, the most by any player in Major League Baseball history.
14 grand slam singles
4 runs
A grand slam is 4 runs. 3 base runners and the hitter himself get to cross home plate.
Grand Slam Single happened in 1999.
Grand Monster Slam happened in 1989.
Golf Grand Slam - video game - happened in 1991.
GRand SLam
Four.
Lawn tennis ,baseball
john linden
It's called a "grand slam."
Grand Slam First PitchKevin Kouzmanoff (Texas) was the first in 2006, Daniel Nava (Boston) was the second in 2010.
Fred Lynn
yes there was a walkoff grand slam this year
It's a homerun... unless the bases are loaded, then it's a grand slam.