so i actually watched it. the result of the experiment was that he did marginally better at league of legends the second month, while on estrogen, but personally i think that playing hundreds of matches for a couple months probably had more to do with it. it is known that practice can improve one's skills, after all. the real takeaway of the video is that it can be pretty freaking hard to get estrogen.
The best way to draw a conclusion is to stop taking estrogen and keep playing until his estrogen level is back to what it was previously and see if there was any correlating loss of ranking.
this, and also have a control sample; someone playing the same amount of games as him but not taking the estrogen at all, to account for the increase in skill after playing so many
it seemed that he must've already been playing somewhat consistently, since the goal was to up his rank, or whatever, but he also acted like keeping to a schedule of 5 matches a day every day for two months was pretty daunting, so i'm guessing he played more, and more consistently, during the experiment, than before.