Double Drag Tap!

Some rudiments are super popular, some are not. Some have obvious every day utility and application, some do not. Double drag tap is a mystery to many, maybe most, drummers, and is even a mystery to many "experts". Please allow me to attempt to unravel the mysteries swirling around this strange rudiment. I don't use it hardly never, but it is very good exercise, and does have merit here and there in the working drummer's world. YES. My posture is TERRIBLE. Always has been. I've lately been working on sitting up straight, and SMILING when I play. This may be my biggest challenge ever!!