Replaying to
https://bitcointalk.org/index.php?topic=1364041.msg13881925#msg13881925Understandable that you are going to attract people to your site first before making some money from the pot. However, the game is not truly fair. I know this is not a lottery like my site and hence it cannot use a method to select a fair winner. From what I know, the winner is the one that give the correct answer (similar by 90% to what you set) within the shortest prior of time. The loophole (to the participators) here is that there is no way to determine who give the correct answer first.
It is fair. There is a way of knowing who is first. How is there not a way? Simply. The first person to solve the riddle and enter their BTC address is the winner. And I am able to determine that.
It is not fair in the sense that your "players" will not know who answered first. How are we, as the player, know who answered the question first? You, as the administrator, said you can
determine who answered first and that is because you have access to the database. We, as the player, do not have access to the database. Even if the player have access to the database, this game is not provably fair at all. Simply because you can edit the database to your gain.
You will need to come with with a method to determine who answered first while the public can also agree with the method.