How much EV did I lose here? BJ question

[Komodo]

Hi. 2$ bet
I had 7 (43 I think) and the dealer an ace and mistakingly clicked on stand. Dealer hit 20 and won.

So my question is 1: How much do I lose on average with this kind of play? Misclicks ones in a while while clearing a casino bonus is probably unavoidable.

And 2: How much did I lose in this particular case where the dealer hit 20?

[SheetWise]

Your expectation playing 7 v A overall is -0.31. By not playing the hand, your expectation of a tie now becomes the same as the dealer busting the A -- about 17% (if stand all 17's, about 20% if hits soft 17). So overall, by playing the hand you should have had a 69% payback -- by not playing you get a 34% payback (or 40%). You lose 29-35%.

But if you're asking about this particular hand when you know the dealer had 20, your return by playing would be a combination of the probability of you drawing 20, and 21. Your return when not playing is -0-. These draws are about 8% and 7% -- so you'd get a tie 8% (8% payback), and a win 7% (14% payback) for a total of 22%. These are pretty rough figures -- but I'd guess you lost about 22% by not playing.