Ali let Foreman punch himself out on the ropes

Going into the October 1974 'Rumble in the Jungle' in Kinshasa, Zaire, George Foreman was an undefeated, ferociously hard-hitting champion who had destroyed the two men who'd beaten Ali years earlier. Almost every expert picked Foreman to knock Ali out early; Ali's own cornermen worried openly that trading power shots with Foreman, or trying to dance and outrun him for fifteen rounds in tropical heat, would both leave Ali finished by the middle rounds.

Standing and trading meant absorbing Foreman's full knockout power directly. Circling and dancing to avoid him meant burning Ali's own stamina in oppressive African heat and humidity against a younger man who didn't need to chase far to close distance. Ali needed a way to survive Foreman's power without spending his own legs or absorbing full-force blows to do it.

Ali covered up on the ropes for round after round, leaning back so the ropes' give and his own angle robbed Foreman's punches of much of their force, blocking and catching blows on his arms and gloves while taunting Foreman to keep swinging - deliberately letting Foreman spend his heaviest weapon, round after round, against a target built to absorb it cheaply.

Ali let Foreman punch himself out on the ropes, using the ropes' give and his own angle to absorb blows cheaply, draining Foreman's power while conserving his own.

The ropes and Ali's angle absorbed much of each punch's force cheaply.

Foreman, thinking he was close to finishing Ali, kept throwing full-power shots.

Each full-power punch cost Foreman far more energy than it cost Ali to absorb.

By mid-fight, Foreman's arms had nothing left, and Ali's cheap defense became the platform for an inexpensive knockout.

When a rival's strength is overwhelming force, don't match it head-on; absorb early blows cheaply and let them exhaust themselves attacking you.

By round 8 Foreman was punched-out from his own missed power shots; Ali knocked him out with two seconds left and reclaimed the title. The tactic entered the boxing lexicon as the 'rope-a-dope,' studied for decades by trainers and athletes far beyond boxing as the definitive example of trading position for an opponent's stamina, and the fight itself became one of the most mythologized events in sports history, chronicled in the Oscar-winning documentary 'When We Were Kings.'