A concept from game theory. A player in an unsafe position will always lose, unless their opponent makes a mistake.
In any turn-based game - yes, even chess - one player starts in an unsafe position. Although this is unfair in a sense, the opportunities for making a "mistake", which in game theory means any deviation from the perfect strategy, are enormous. Also, I don't believe we yet know which player in chess starts in the unsafe position, although I'd imagine it's black. Let me know if you know better.
For a simple illustration of unsafe positions, see Wythoff's game.