However predicting last letter of block hash is really hard and risky and also wining 8 mbtc is not much as there is high probability that a single number may not came up in block hash for even hundreds of blocks. But wining 16 times is really good odd and i haven't tried betting in this site yet.
This is really hard to predict 1 correct digit out of 16 even it's risky but nice to place bet on blockchain based game, I played on that site and placed few bets there but I was not lucky to make the correct prediction there, because where players have very low chance to win and it's all about luck.