If there's anything about Mario Party that you need to know, it's that there's no winning or losing strategies. Things in the game just happen, sometimes completely randomly, and chaos theory rules the day.
That is best exemplified in this video, where a group of friends plays together and thankfully have microphones while they do it. Watch the video below (warning, it's loud):
The player controlling Toadette is happy to note that, with eleven stars on the final turn, they are pretty much guaranteed to win. However, on the final move, Luigi rolls a high enough number to reach a spot that performs miracles. The miracle worker exchanges stars between Toadette, who had a commanding lead, with Waluigi, who had zero. This propelled Waluigi into the lead from dead last, ending the game.
Our Take
This is why you never declare victory before the final score is tallied.