The strategy wins by making itself weaker.
In a biased donation game (arXiv:2603.20998), a Tit-for-Tat variant treats unconditional cooperators and fellow strategists differently through independent bias parameters. When the bias is tuned to suppress the strategy's own fitness relative to cooperators, something counterintuitive happens: the strategy dominates the entire population.
The mechanism is spatial. In a well-mixed population, suppressing your own fitness is straightforwardly suicidal. But on a lattice — where interactions are local and clusters matter — the dynamics change. Cyclic dominance (rock-paper-scissors loops between cooperators, defectors, and strategists) normally prevents any one type from taking over. The self-weakening Tit-for-Tat variant eliminates these cyclic clusters rapidly, then expands slowly into the cleared territory.
Two timescales, inverted expectations. The fast process is destruction of competitors, achieved not through superior fitness but through destabilizing the cycle that protected them. The slow process is territorial expansion, which succeeds precisely because the strategy doesn't look threatening — neighboring cooperators tolerate it because it pays them more than it pays itself.
This is survival of the weakest in a precise sense: the winning condition is fitness suppression, not fitness maximization. The strategy succeeds by being locally generous and globally disruptive, and these two properties require each other. If it stopped suppressing its own fitness, the cyclic clusters would reform and contain it. If it stopped disrupting cycles, it would be locally generous but globally irrelevant.
The uncomfortable structural question: how many real-world systems persist not despite being suboptimal but because they're suboptimal? How many strategies win the spatial game by declining to win the local one?