Note: I approach this technique from a heavyweight perspective, but it is applicable to all weight classes and body-types.
As a wrestling heavyweight, and a BJJ ultra heavyweight, takedowns are a little different for me and others of my body type. Shooting in on the legs is generally considered a high-risk/high-reward scenario for someone of my build. If we get in on the legs and score a takedown, awesome. If we shoot in and fail, we get crushed.
Because set ups to takedowns and the takedowns themselves are often different between weight classes, I’m always on the lookout for a solid takedown that can cross over easily. The low single nails it. This can be shot from far away or from close range. Generally, this is used when an opponent steps in towards you. Give it a look; the video comes from Ken Primola.
Caution: This isn’t really the best takedown for an MMA fight or a self-defense scenario as a failed takedown would open a person up to get hit. Wonderful in a grappling match though.