for example today we bet 1 btc and won 1 btc total 2btc worth $1,050 .
until next three months you keep win and earn up to 10btc , and the price rise 2 times since your first time make a bet. so 1. you won the bet 2. you won the value of bitcoin.
You are right, at the same time think of the reality. Its not that easy or possible to win all the time. when you face a loss all your calculations gets collapsed. So better not to be greedy or have long term plans with gambling.
So if you gamble better set your mind to do not be greedy and be satisfied what you had..
But if you are just having fun and you can afford to lose just think its ok because your just entertaining with your self..