In the long rivalry between New Zealand and South Africa, two rugby nations whose identities are bound to the game itself, a fourth and deciding Test looms in Baltimore — a city far from the ancestral grounds of either tradition. The All Blacks arrive wounded, missing their captain and a trusted lieutenant, yet carrying a tactical blueprint drawn from the one moment in this series when South Africa's fortress cracked. What unfolds on Sunday will ask whether experience can be replaced by hunger, and whether a team can execute its best rugby precisely when the margin for error has disappeared.