That's funny. I always play "safe", i mean i had like 1250 sat, and i bet 1 sat with 100% on loss (classic). Very approximately, it means I have to lose 10 times in a row to lose it all, which means again approximately 0,5^10 chance to lose = 0,00048% chance. And guess what ? Yes, I lost it all.
It is kind of weird, i don't get how people can win that much money (High rollers, they're insane right ?) ..
it depends on which chance are you playing at was it 2x. at 2x 10 time lose is so unlucky but not impossible
and the high roller place insane bets and win insane and/or lose insane just check their profile and see what is their profit + or -