Anyone know how to do a BLJ? I need help

start doing a long jump chain then point toward mario's back

guessing you're trying to skip 3rd door or last staircase?

I get the general concept of it, it just never seems to work... I reach the top of the stairs having done the jump like 5 times, they did it 40 times by then

you just have to tap A very fast, thats what i did and it works just fine