I have just started speedrunning this game with my friend, and we noticed in the top runs the green triangle is skipped. Is this pure luck or is there some formula behind it? Also, is there some community like a discord that we can discuss strats in?

pure luck you guess the last number :)

the last number is pure luck, but in some runs people will even skip the last two numbers. most people don't do that because there's only a 1 in 20 chance of the combination being right so it cant produce consistent runs