I had no idea. Shame as I think it definitely has merits as a system of relegation / promotion. It'd certainly stop the whole "scrape into the playoffs in sixth and fluke through it" shit we've seen before.
Interesting way of doing things!
I've always been a fan of: bottom two go down, third bottom goes into a play-off game with the third placed team from the division below. Fair few leagues do that I seem to recall. It sort of says "neither of you two were quite good enough over the course of a...