The world where traders take personal responsibility for THEIR choices. Most don't retailers short don't .... because they are afraid to. So they find all kinds of reasons why it doesn't work. "If the shoe fits".
Then I'd recommend you to watch the whole vides, as I didn't suggest to go short in the first 30 min, but to have that as the risk lvl. And in general - it was a video showcasing an idea and the process of coming up with a strategy, and not necessarily implementing this exact one.
Your calculations are based on a set of rules and a period in past. You have for that period indeed 84% of winning trades, and numbers about winning and losing trades. The problem now is that these stats have no value at all for future. I am sure if you would use the same set of rules for another period all the numbers will be different from the numbers you had in your video. That is logical as market behavior is dynamic, not static. So your statement about 84% is worthless. Unless you confirm in writing that , if I use the rules you used, I will have 84% winning trades and the expectancy ( which is calculated with avg profit and avg loss per trade and % of winning and losing trades) will be exactly the one you had in your video. And you should confirm that you will take the losses if there are any beyond the results of what your video gave. You might as well just optimize a MA to record returns and state that this will be the results in future. Complete nonsense. Do the test: change the period and leave all the rest the same. I am sure your numbers will be different. And that is logical as the data will be different. You cannot have the same results with different data. Also, depending on the strenght of the trends, the values on the exit moments can be at much higher or lower prices then in your video.