"ryo" - both
"tan" - ends
Ryotan wins the award for most useful silly technique. It started as a way for me to play fast doubles with odaiko bachi but then proved useful in a multi-drum setup, and then on naname as well. It's particularly mind-bending to practice because the wrist moves opposite a regular strike.
The ryotan strike starts with the butt of the bachi raised and the tip of the bachi near the drum. The butt is then thrust down into the the drum hitting first and a relaxed grip allows the tip to create the second hit.