As far as I get it, the problem here is that he is trying to calculate the house edge, disregarding the skill/decision making that comes with blackjack, isn't it?
The problem is he's being willfully ignorant because there's no evidence that he was cheated, but he really wants to convince people that he was (because he lost and I think his account was frozen for some reason).
Stake provides very basic statistics in each players profile. Total bets, total number of bets won, total number of bets lost, and total amount wagered for each currency.
It doesn't include total amount won - just the total number of bets wonBlackyJacky is trying to claim that the stats represent how many units he has wagered. For example, if he doubles and loses, that's two bets made, both considered lost bets. This is not how it works.
The way it does work is each round counts as 1 bet and has a unique bet id with it's own bet history. If he profits overall for the round, that's 1 winning bet. It doesn't matter if you split, double down, win even money, or hit a blackjack for 3-2. One round counts as one bet in the stats.
So he's trying to claim that his stats can be used to determine his ROI (which he calls "expected RTP"), which is not possible. To calculate your ROI, you need to know how much money you wagered, and how much money you won. The stats don't include how much money was won, so we can't make the calculation.
Also worth mentioning, even if he was correct about everything above (he's not), his calculation would only be accurate if all ~181,000 bets made from his account were the exact same amount. Never increasing or decreasing his wager. And they would have to be all black jack, no other games.
I believe he realized he was wrong a while ago and is just spreading lies out of a combination of spite and ego. Shameful really.