The outcome is not in doubt, now it's time to celebrate
Background: Sometimes: All over but the shouting
The earliest known written use of this expression is in The Sporting Magazine (a UK journal) in 1942, in an article by Charles James Apperley, writing under the pseudonym of Nimrod.
But there are two conflicting origins for the expression. The first dates back to the nineteenth century when ballots were counted by hand and the results were not available until long after the polls had closed (due to the time taken to hand count). The announcement of the start of the count often triggered a loud roar from those who had voted. In a one sided contest, it would be obvious who the winner was at this time because of the volume of cheering for a particular person. In other words, the outcome was unofficial but decided - it was all over bar the shouting.
The second is that the shouting refers to any arguments that take place after the outcome of an event is already decided which, taking the expression at face value, would seem to be the more plausible option.
These days the expression is usually used in the context of celebrating a political or sporting win - when the hard work has finished and all there is to do is celebrate.
"Goliath lay where he had fallen, staining the sandy earth brown. There was not even a twitch. My joy was immense... It was all over but the shouting, and God knows there was plenty of that." - Joseph Heller, God Knows (1984)
Judge rules unused Borders gift cards to be worthless(May 23 2013) Borders owes nothing to holders of roughly $210.5 million of gift cards that had not been used by the time the bookstore chain shut down, a Manhattan federal...