Does this mean that the top left corner had a higher probability of being a mine? Or even a lower probability, seeing as the dev would have had to ensure that it's not a mine before the user clicks.
Now that I think about it, the dev strategy of leaving the spot without a mine but moving one there, probably does not affect the probability that there will be a mine there during gameplay.
I don't think the dev would leave the top left without a mine until one is moved there, as that would always be a safe square to click first.
So if the probability of finding a mine at any given spot is given by p, then the probability of finding a mine in the top left during gameplay for cases where one does not click it first (in which case it is 0?) is 1 for the case where you clicked on a mine first with probability p, and then p for the remainder.
So the total probability p' is p * 1 + (1 - p) * p, or 2p - p^2.
Wikipedia says
> Beginner is usually on an 8x8 or 9x9 board containing 10 mines, Intermediate is usually on a 16x16 board with 40 mines and expert is usually on a 30x16 board with 99 mines; however, there is usually an option to customise board size and mine count.
8x8 10 mines p = 0.16 p' = 0.29 ratio = 1.84
9x9 10 mines p = 0.12 p' = 0.23 ratio = 1.88
16x16 40 mines p = 0.16 p' = 0.29 ratio = 1.84
30x16 99 mines p = 0.21 p' = 0.37 ratio = 1.79
I was curious to see the concrete effects for no reason other than to procrastinate.
