Is there any way to prove house edge is 1%?
Yes! RHavar has just explained it on another thread :Thank you very much for these very precise and clear clarifications RHavar. 
But now, I don't understand why you're dividing "97" by this number :
crash = Math.floor(97 / crash);
I'm sorry for these questions but I'm trying to understand how that works.
TYVM RHavar
But now, I don't understand why you're dividing "97" by this number :
crash = Math.floor(97 / crash);
I'm sorry for these questions but I'm trying to understand how that works.
TYVM RHavar
So the first thing to note is that a final outcome of 123 means a multiplier of 1.23x. So `123 / crash` is easier to reason about if you think of it more like `1.23/crash` in maths terms. And as we already discussed, `crash` is evenly distributed between 0 and 1. So if you wanted to simply turn it into a multiplier you'd do: `100 / crash` ... but no casino is going to do that, as they need a house edge for themselves. I know bustabit effectively uses `99 / crash` to make a house edge of 1%, but rocketpot is using `97 / crash` which is going to result in a significantly higher edge (of which some will be used to fund the bonuses/jackpots/other benefit thats bustabit might not have).