> One of the bottom squares contain a mine, but it's impossible to say which one. You have to select one of them. But according to what I just said, that would mean certain death! I wanted the game to be cruel, but now it's unwinnable. So I'll modify the idea a bit and say you are allowed to guess, but only if there are no safe squares left. This way, the game will be cruel, but fair.
The situation when your only move possible is a guess is exactly the same we have in the very beginning of the game so I would rather make such fields guaranteed safe the way the first click is.
If you read through the rest of the article, that's actually the end result! Ambiguous squares are guaranteed not to be mines iff guessing is the only possible move.
On the flip side, the game punishes you for guessing by guaranteeing ambiguous squares result in a mine iff there there are moves you could make without guessing.
The situation when your only move possible is a guess is exactly the same we have in the very beginning of the game so I would rather make such fields guaranteed safe the way the first click is.