Try at freebitcoin. I can't give you any good strategy just used the common strategy of Hi- Lo game that is quite related to dice game. Also try your luck on the lottery and the a chance to win a higher amount from their faucet.
if the OP wants to try with freebitcoin then I am suggesting to be careful and only use money which he can afford. I can suggest like this because I have bad experience in the past and makes me lose the most bitcoin I have and I don't want other people have the same experience with me. first, you can try with small amount, do it for 3-5 times and if from that you can get all winning, then you need to stop right away and try again in next day. because if you continue, I guess you only get lose every thing you have like I did in the past.
The technique here if you don't want to lose your money too much is stop in an instant if you are losing in a row, it is a sign that the house will just take all the money that you have and you have no chance of winning, maybe you do have, but the chance is very low. This is always like this, first, the house will going to let you win, but afterwards, you are going to lose many times until there is no more remaining bitcoin in your wallet.
A likely theory. But again the house/site doesn't manipulate results. They are provably fair and you have your way to verify it.