Not all the bitcoin users are mathematically competent. We do have our very own expertise and in gambling everyone still needs to have luck. And although there might be the days of unluckiness, it's very easy to say whether it's our lucky. When you are winning some good amount for this day, expect that this day is your day.
Yeah you cannot say that you are lucky enough if you are only aiming to earn for good amount. But if you are starting to earning good amount by that day then you can see for yourself that you are lucky. Losing is always there and most of the time we are expecting more about losing when we are starting to win with a lot of winnings.