The one that he demonstrates first. After the trapeze and his bro, you swing all the way over all of your fingers, then into a normal double or nothing. Just follow what he shows in the video, its not too hard to follow.
But in the McBride roller coaster video, he mentioned, “instead of just going straight in to double or nothing, you go all the way back around into a real double or nothing” and at that time, he was referring to rewind when he mentioned “going straight into double or nothing”.
The reason why its on his thumb is because he was teaching wrongly. He just got confused. Make sure you go all the way around both of your hands and go into a normal double or nothing. This will make it a normal double or nothing, and a normal triple or nothing.
Yeah, he was trying to teach an easier way of doing it because many people struggle with separating the strings. You want to have all the strings on one finger so that you can roll out of the triple or nothing.