If you're going to tell your readers to read an article, you should at least read it yourself first.
The prank that Cal Tech pulled at the Rose Bowl with the Cal Tech sign was in a game that was Minnesota vs. Washington. They didn't hand out the signs, the broke into a hotel room, and changed all the instructions for the signs that the Washington cheerleaders were already going to hand out. That way, the Washington cheerleaders started their routine, and everything went well for the first 11 images, and then the Cal Tech prank took effect.
It looks like you tried to do research, but didn't actually read the information you found.