Sorry, but I learn freebitco.in very well since I've joined it about 2 years ago. I'm not a newbie 
Unfortunately I'm a looser more than newbie:
https://i.imgur.com/0ApWh1y.png
Unfortunately I'm a looser more than newbie: https://i.imgur.com/0ApWh1y.png
I think you have chosen a wrong site to play dice game because you already know that this site has got
You need to be lucky to make a money from this game and our experience will not matter much. 6+ BTC is not a small amount at current market price so you should know now gambling is not for making money.
A little bit correction, it should be 5% House Edge instead of Bankroll.
I do not think he is wrong to play at freebitcoin, maybe he like it so much so he do not really care about house edge or maybe he did not notice that it has higher house edge compared to usual dice game.
I'm wondering, when did he lose that much BTC. If it was happened years ago, means that he lost few thousands or even few hundreds dollar only. But if he lost it in the last few months then it is so big amount.