In the beginning, while manipulating the Cupheads about 15 years ago, Jay Gilligan noticed that to release the ball from the cup, a small Multiplex could be performed where the club passes to the other side.
When he throws them, they are thrown at the same time, reach the same height in the air, and consequently, land at the same time in his hands.
He started experimenting with a pattern using three clubs and one ball. In this configuration, the clubs perform a one-spin pattern while the ball stays on one side.
He realized that the ball could be on either side of the pattern as it is symmetrical. So, he learned to do it with the ball in his right hand as well. Then he thought about having one ball on each side and creating a configuration with five objects.
However, when he tried to perform this pattern with one ball on each side, he couldn't make each side happen quickly enough. It had something to do with the synchronization of the catches.
After a year of practice, he realized that by holding the club by the body instead of the handle, he could make the objects reach different heights and, consequently, land at different times.
Once he discovered that he could hold the club by the body, he was able to perform a Multiplex where the club goes higher than the ball. This allowed him to create the desired pattern where the ball falls first.
The first version of the five-object configuration he successfully achieved was a flat throw. It was very challenging, and he had to learn how to start and stop the pattern.
Later, he discovered that he could perform a normal flip instead of a flat throw. It was much easier, but for some reason, he didn't try it at the beginning.
It took him two years to discover all of this, which allowed him to understand how the mechanics of these Cupheads work with other objects and how different variables like multiplexes with different timings, heights, and patterns can be manipulated. By embracing the mindset of seeing failures as opportunities to learn and improve, he was able to unlock a whole new world of technique with the Cupheads.