Subframe Grinding
Subframe Grinding[1] is a hyperspeed glitch that allows Mario to build up speed.
Execution
This is more of a collection of techniques that fall under the same idea. This is when you start a frame in a ground action, but for whatever reason are no longer on the floor. Mario then enters freefall, takes an air step, then lands on a floor.
If you repeat this process, you're able to accelerate via air frames and skip the ground frames entirely.
Pedro spots are an example of this, but techniques without pedro spots were recently developed. These include:
Uses
No real potential uses at the moment.
It was once thought to be used in the A Button Challenge in TTC to build up speed for a hyperspeed jump, but that is now obsolete.
Note that these alternate methods cannot be used in place of a pedro spot for the purposes of RLB.