I'm having a hard time following this one:
ah yeah, that does sort of jump from zero to 100
That's a knot that's used for climbing with rope and harness/belt (also with a carabiner).
I had a brief spell attempting to climb walls with a friend - I did learn that knot, but dont know if I could reproduce it now.**
The video doesnt help any - I wonder is that knot described elsewhere and they forgot to let us know about it.
** It is very important that the two strands dont 'overlap' each other. I *think* that's what they're trying to say in the last image ["Wrong"]: "a kink in the standing end is an error"
- but I couldnt be sure there (standing end? - I never did learn the 'knots' vocabulary...)