First off use this link
http://freebitco.in/?r=9930
Register on the site with your bitcoin wallet there is no charge
ROLL	0 - 9885	9886 - 9985	9986 - 9993	9994 - 9997	9998 - 9999	10000
PAYOUT (BTC)	0.00000667	0.0000667	0.000667	0.00667	0.0667	0.667
Proceed to roll,you can roll once per hour even at the lowest value its still a great gain!
Next you'll see the multiplier factor,DONT jump the gun.
The optimal Multiplier with the most probability of gain VS loss is at x3 Since you have a one in 3 chance of being right.
Stay with the same value low or high and bet in a conistant way that buildings your BTC amount. Do not just throw your money away,set a limit I.E Gample half of the 667 you gain,keep the rest if you are lossing then try again later you win some and you lose some.
Ideally gamble in a 3 hit rule,That way you will keep your money if you hit once,you lost nothing. If after 3 hits you haven't won anything stop and go away for a while then come back in an hour. It keeps you from spending what you've earned and gets you ready for a higher roll down the road.