Let's take a look at the 20 players that have hit a grand slam on their birthday in real games since 1914:
I used the Baseball-Reference Play Index to find the 55 players that had a home run and at least four runs batted in on their birthday. Clicking the number in the plate appearances column shows a pop-up window with play-by-play data, quickly whittling down the list. For games without B-R or Retrosheet PBP, line scores without four runs in an inning eliminated a player, while newspapers helped knock out two other entries before confirming our final birthday slam.
The youngest player on the list is the most recent one, with Colby Rasmus doing it on his 24th birthday. There's a tie for the oldest, with Vince Coleman (a Dave Niehaus grand salami in Seattle) and Hideki Matsui, hitting ones on their 34th birthday.
Alex Rodriguez has the only walk-off, but despite it coming in the top of the inning, I think Shoeless Joe Jackson has him beat with a come-from-behind, inside-the-park game-winner. From the Chicago Tribune:
"...needing one run to tie, they got the bases filled and then Gen. Joe poled a tremendous drive to the flag pole in deep center for a home run, driving in three mates ahead of him and clinching victory by a score of 8 to 5."The game story even detailed the start of the ninth-inning rally, allowing me to include Leibold, Collins and Weaver in the runners column. It also notes that in the first game of the doubleheader, Red Faber outdueled Walter Johnson and snapped Sam Rice's 29-game hitting streak. The Tribune's archive is awesome. I don't even know how far it goes back and has pretty much every day's paper. Great for anyone doing just about any kind of research.
It's been more than four seasons since anyone has joined this list, will anyone do it in 2015? It looks like our first chance is with Alexi Amarista (born April 6, 1989) on Opening Day! OK, so he's hit 15 career homers with exactly five each in the last three seasons. Maybe Adrian Beltre on April 7 is a better bet...