Looking for a short story that takes place in a baseball
stadium/stand.  A guy has a little angel/alter ego talking to him
throughout the game. Some words from the title are The Night Manny....
stole home? base.

Hello.

The story is probably "The Night Manny Mota Tied the Record" by W.P.
Kinsella.

On a web page called, "Guide to Baseball Fiction: W.P. Kinsella," the
detail that you mention about the angel is described as follows:

"An angel offers a fan the chance to exchange his life for the late
Thurman Munson's." [description of  "The Night Manny Mota Tied the
Record" ]
The web page is hosted by University of Texas - Arlington:
http://www.uta.edu/english/tim/baseball/kinsella.html

The story is included in an anthology called "The Thrill of the
Grass," listed on Abebooks.com:
http://dogbert.abebooks.com/abe/BookDetails?bi=71704528

"The Thrill of the Grass" is available from Amazon.com:
http://www.amazon.com/exec/obidos/tg/detail/-/0140073868/

search strategy: baseball, fiction, "night manny"
I hope this helps.

That's it! Awesome! Thanks so much!