Tit for tat is not a winning strategy in the game theoretical iterated prisoner's dilemma. It is a winning strategy in a competition between strategies, but the

Tit for tat is not a winning strategy in the game theoretical iterated prisoner's dilemma. It is a winning strategy in a competition between strategies, but the incentives of these competitions do not align with the actual game. In fact, the strategy by definition never leads to a win and is weakly dominated by just never cooperating.