Ok - In craps it is possible for someone to preset the dice and throw 1000 times and alter the expected distribution. Assuming the thrower has spent countless hours practicing his skills and assuming there was no pit boss saying you cannot throw the dice above the level of the table.
So define flip - what is a legitimate flip? Someone could practice countless hours and develop their skill to the point they may be able to consistently alter the results in their favor - say heads? Offered to bet you 500 to win 500 that in 100 throws he can throw 51 or more heads.
What would your response be if the other bettor offered you 480 to win 500?