So if I will depost 1BTC my chance to win will be 100% or I got this wrong please tell me more about how it's calculated?
And it means someone who have only 1% to win will not win?
It depends on the total pot, and I'm sure no one will have 100% chance of winning unless you are the only one who play. Lets say you send 1btc and the total pot is 2btc, means that you have 50% winning chance.
Someone with 1% still have the chance to win the prize because it is provably fair lottery but he will need a great luck to win with only 1% chance.