The article had an illustration of this: the player put their opponent into check where there was only one move to get out of check. The opponent would have to make that move, whether they were human or machine, so the player who made the original move wins the game.
It is an interesting variation on chess given the current state of tournament play, yet it isn't really a solution to the cheating problem since it is effectively a new game with a new end-state. But you are probably right about there needing to be some sort of threshold. While there the rules of the variation says that any move with equal scores is considered equivalent, I would imagine the players would need a very intimate knowledge of how the engine scores moves in certain scenarios.
It is an interesting variation on chess given the current state of tournament play, yet it isn't really a solution to the cheating problem since it is effectively a new game with a new end-state. But you are probably right about there needing to be some sort of threshold. While there the rules of the variation says that any move with equal scores is considered equivalent, I would imagine the players would need a very intimate knowledge of how the engine scores moves in certain scenarios.