Games of hidden information are very weird in their randomness.

Minesweeper, of course, is well known to be annoying for its randomness, which is why I went to the effort of writing a version that didn't require random guesswork. When you have no choice but to take a risk, it's annoying to be wrong because it terminates your game.

But I've recently been sent an implementation of the puzzle/board game ‘Mastermind’ for my puzzle collection, and I've been finding that the annoying randomness works the other way in that: it's much more annoying to be right. When you've just constructed a guess which you've carefully designed to narrow down the possibilities and bring you one step nearer to the actual solution … it's terribly irritating if that guess turns out to be the exact answer. In a game played against an opponent, where each of you was scoring points for how quickly you solved the other's problems, this would at least be useful to you because you'd get a lot of points for it. But in a solo context, you're not really after the high scores; you're after the satisfaction of reasoning your way to the answer step by step, and to unexpectedly hit the right combination at an early stage rather spoils the fun.