The probabilities for a player to win a Mines game with a specific pre-chosen amount of mines and selected tiles (revealed slots) are calculated and shown in the table below:
With the probabilities the multiplier is set such that the expected return is 0.99 with the following formula:
The multipliers can be found in the table below:
Note: The multipliers of the Mines game can't be found in the code, because the multipliers have to be set when the contract gets deployed. Invoke the functionMines_GetMultiplierson the deployed contract to verify the multipliers.
The house edge is incorporated in the multiplier. With the multipliers and expected return set at 0.99, the house edge is 1%.
The average multiplier is determined leading to the following odds: