Measuring each crypto to fiat bet is going to leave you "crazy"
and it is a very bad bankroll management, that is we bet on crypto, no!.
If you do it in a stable coin, this explanation will not help you, so, if anything crypto has, it is that if you do not change it to Fiat, then e.g. 1btc=1btc.
1BTC (let's use round numbers) is now worth $25k, and who cares! so you still have 1 BTC, it is worth mentioning the opposite case you are happy when it is at $50k! if that is your situation with money in a casino, the above, remember the premise do not bet money that you do not allow yourself to lose.
The reason! well, you are using money that can affect you even without even having bet it, that is serious, you feel that you lose money without even making a bet.
As long as you have your money in a casino your goal is to make a profit, on what factor (ROI)? well, that is a very personal matter, but if you deposit 1BTC and then withdraw 1.5BTC you won 50%, it is profits very good...
After that money leaves the casino, taking it to -fiat has a relationship associated with your losses or profits from the trade at that moment, in this precise case 50%, that is, you now have +$12.5K in fiat and 1BTC.
And it is worth saying in the same way that the calculation of the size of the bet is made based on 1BTC, and that is a separate issue because it depends on the game, but making it generic if your strategy is to make 1000 bets to obtain a return on profit, you betting is 0.001 BTC.
This Post is not gambling advice, investment, deposit.
Hypothetical case(e.g.):
bitcoin price $50k deposit.
bitcoin price $25k withdrawal.
Tip: please do not deposit money in a casino that you do not allow yourself to lose and also remember the volatility of the crypto market.