[math-fun] lottery thought problem

design a simple-looking powerball-like lottery variant that has three properties: (0) it's easy to determine that a given bet has won after the drawing is made (1) it's nevertheless quite difficult, even for a mathematician, to work out the exact chances that a random bet wins [ this is the hard one. i want to do this via some type of hysteresis related to the ensemble of numbers played in the previous lottery draw, maybe ] (2) it has the property that with probability at most 1/10,000, no one will win even if hundreds of millions of people play every week for one thousand years. -- Thane Plambeck tplambeck@gmail.com http://counterwave.com/