Rafael Nadal –. His French Open legacy may be waning following his quarterfinal exit, but having accumulated 9 Roland Garros titles in the past decade (to go along with 5 other Grand Slams), the Spaniard has captured 14 Major titles and is tied with Pete Sampras for 2nd most all time!
http://blog.tennistours.com/2015/06/11/tennis-players-with-the-most-grand-slams-in-the-open-era/
Nelson Cruz and the 10 Greatest Grand Slams in MLB Postseason History. Nelson Cruz and the 10 Greatest Grand Slams in MLB Postseason History. Only in the grand game of baseball can magnificent historic accomplishments intermingle so seamlessly with the feats of the present day.
http://bleacherreport.com/articles/888561-nelson-cruz-and-the-10-greatest-grand-slams-in-mlb-postseason-history
Robin Ventura has been in the news recently due to the fact that he was named the Chicago White Sox's successor to Ozzie Guillen as skipper. But in 1999, Ventura hit a walk-off grand slam to beat the Atlanta Braves in Game 5 of the NLCS.
http://bleacherreport.com/articles/888561-nelson-cruz-and-the-10-greatest-grand-slams-in-mlb-postseason-history
Date: 4/23/1999. Set By: Fernando Tatis. Joe Buck rumors aside, Fernando Tatis did not do much of anything in his brief three-year stint as a St. Louis Cardinal. However, he defied pretty much all odds one night in April of 1999 when he managed to not just hit two home runs in an inning (which has only been done 57 times in MLB history), but had both of those be grand slams.
http://www.complex.com/sports/2013/03/50-most-unbreakable-records-in-sports-history/most-grand-slams-in-one-inning-2
Roger Federer at the 2014 US Open Tennis Championships! 4. Steffi Graf –. The all time Grand Slam champion leader is a woman from Germany who won an astounding 22 titles. The only player to ever complete a Golden Slam (all 4 titles in one year), Graf ruled the late 80’s to early 90’s of women’s tennis.
http://blog.tennistours.com/2015/06/11/tennis-players-with-the-most-grand-slams-in-the-open-era/
Grand Slams Records. One of the rarest events in baseball is HITTING TWO GRAND SLAMS IN THE SAME GAME BY THE SAME PLAYER and they are all listed (along with box scores, positional breakdowns, and trivia items) in our fabulous feats section. On May 26, 1929, New York Giants pinch-hitter Pat Crawford hit a grand slam.
http://www.baseball-almanac.com/recbooks/rb_grsl.shtml
Aramis Ramirez, Chicago Cubs: Game 4, 2003 NLCS. 3 of 11. This grand slam is notable for many reasons, perhaps most importantly because this can be viewed as one of the last positive things that happened to the Chicago Cubs during the 2003 postseason.
http://bleacherreport.com/articles/888561-nelson-cruz-and-the-10-greatest-grand-slams-in-mlb-postseason-history
For Major League Baseball: Between 1998 and 2008, an average of 135.6 grand slams were hit per season.[1] 30 teams play 162 games each (with 2 teams participating in each game), so that means that a grand slam is hit roughly once every 18 games. Each team bats about 34 times per game in the major leagues[2], so that means a grand slam is hit about once every 1219 at bats.
https://www.quora.com/How-rare-is-a-grand-slam-in-baseball
In 1987 Don Mattingly set the record for most grand slams in a single season with six. Alex Rodriguez has 25 career grand slams, the most by any player in Major League Baseball history, passing Lou Gehrig's 23 on September 20, 2013. Meanwhile, Don Mattingly set the one-season record with six grand slams in 1987 – remarkably, the only grand slams of his major league career.
https://en.wikipedia.org/wiki/Grand_slam_(baseball)
Les Bell, from the Boston Braves, pinch-hit and also hit a grand slam. This is the only time in history two pinch-hitters have each hit a grand slam during the same game. Jim Northrup in 1968, and Larry Parrish in 1982, are the only players in Major League history to hit three grand slams during the same calendar week.
http://www.baseball-almanac.com/recbooks/rb_grsl.shtml
who has the most grand slams in one season
Don Mattingly has the most grand slams in one season.  Don Mattingly has the most grand slams in one season.