They created the 20 turnovers that really hurt us in the course of the ballgame.
From the dailynews.com
What we have here is the backyard, ballgame-on, beer-hugger version of all that.
From the newsobserver.com
They score a touchdown at the end of the half, it might be a different ballgame.
From the jsonline.com
We just could not mount enough of an offensive standpoint to make it a ballgame.
From the thenewstribune.com
He remembered attending a Miracle League ballgame in another town years earlier.
From the post-gazette.com
It was a heck of a ballgame, but right there at the end we didn't make the play.
From the denverpost.com
There's no need to ask permission to skip out of the office to catch a ballgame.
From the forbes.com
We have 4 picks and a couple fumbles, and that's the difference in the ballgame.
From the dailyherald.com
Starters weren't going deep into the ballgame, we were using our bullpen a lot.
From the bostonherald.com
More examples
A particular situation that is radically different from the preceding situation; "HDTV looks the same but it's really a whole new ballgame"
Ball game: a field game played with a ball (especially baseball)
An operation or a contact
There are two interpretations to this. 1) Poster is making a statement acknowledging that he is aware of what is currently going on. 2) Poster is making a conjecture that the game is, for all intensive purposes, over. (h/t to Wraithpk).