at PD you can put no maximum amount for bet like 100 Btc or 1000 Btc as many as you want, because PD has much big bankroll for instant payment.
Wrong, read the above posts, it has been explained by the post just above yours, please do read it
It actually is max 'bet + profit' = 20 btc. So i.e. you can bet 10 btc max on 50% odds (10+10) or 2 btc max on 10% odds (2+18) and so on.
in short, you can only get 20
BTC max profit / roll . But it seems like this is wrong either, shouldnt that 20
BTC is only max profit and not maxt bet + profit .
tl;dr it should be that the max bet on 50 % is 20
BTC since it will get you 20
BTC as well and it is the max profit for each of the roll