Sugar Ray Robinson tells the reason why he retired at 31...interesting.

Of course he came back but at 31, his feelings: Then Robinson undertook his greatest ring challenge. At Yankee Stadium on June 23, 1952, he sought to wrest the light-heavyweight championship from Joey Maxim. A victory would give him a title in his third weight division at a time when the phrase “world champion” really meant something. Only Henry Armstrong and Bob Fitzsimmons had accomplished that feat before. Maxim was a shade younger than Robinson and, more significantly, outweighed him by fifteen pounds. Robinson was a 7-to-5 favorite because of his extraordinary skills. But fighting for the 175-pound championship was a tremendous reach for a fighter who’d begun his career at 135 pounds. “How are your legs?” Robinson was asked several days before the bout. “I hope they’re all right,” he answered. “This would sure be a bad time for them to go wrong.” The temperature in the ring on fight night was 104 degrees. It was the hottest June 25th in the history of New York. “A miasma of cigarette smoke hung over the ringside seats on the baseball diamond,” A. J. Liebling wrote. “There was no breeze to dispel it, and the American flags on the four posts at the corners of the ring drooped straight down.” “I thought I was being roasted to death,” referee Ruby Goldstein said afterward. The first ten rounds were slow-paced, with Robinson piling up a lead on the scorecards. Later, he recalled, “Maxim was an easy target. In the seventh, I stunned him with a right hand to the jaw. But the heat was beginning to get to me. After the ninth, I plopped on my stool. ‘I don’t know what’s the matter,’ I said. ‘I’m getting sleepy.’ That is the last memory I have of anything that happened that night.” At the end of round ten, Goldstein collapsed from the heat and was replaced by Ray Miller. The new third man in the ring broke clinches more quickly than his predecessor and the pace of the fight quickened a bit. “In the eleventh round,” Dave Anderson recounted in the New York Times, “Robinson jolted Maxim with another right hand to the jaw. But when the bell rang, he wandered aimlessly toward a neutral corner.” In round twelve, Robinson forced himself onto the attack again, scoring repeatedly but at the expense of the little strength left in his reserve. Then he hit the proverbial wall. “When Robinson came out for the thirteenth,” Liebling wrote, “he walked as if he had the gout in both feet and dreaded putting them down. When he punched, which was infrequently, he was as late and wild as an amateur; and when he wasn’t punching, his arms hung at his sides. Maxim, at first apparently unable to believe his good fortune, began after a period of ratiocination to hit after him. Then Robinson, the almost flawless boxer, the epitome of ring grace, swung wildly like a child, missed his man completely, and fell on his face.” Robinson rose and finished the round. When it ended, he hung onto the ropes in a neutral corner. His cornermen dragged him to his stool, held smelling salts beneath his nose, and pressed ice against the back of his neck. A commission doctor asked Robinson if he could stand up. The two judges had him leading Maxim 10-3 and 9-3-1 in rounds. The composite score of the two referees had him ahead 7-4-3. In other words, under the round scoring system then in effect in New York, all he had to do was finish the fight to win. Robinson shook his head. He was physically unable to rise from his stool. The bell rang. Maxim was declared the winner by knockout at the start of the fourteenth round. After the fight, Robinson suffered from delirium in his dressing room. His body was covered with blisters and he had lost twelve pounds. He refused to go to the hospital and was taken to his mother’s home. Two months later, Robinson announced his retirement from boxing. He was thirty-one years old. “I do not feel I can any longer give the public my best as it has come to recognize it,” he said. “I know better than anyone else how good I am and what my limitations are. I find I can’t move in the ring with the same speed, dispatch, and accuracy. My instinct used to guide my hands and feet. I could see the opening in a flash and, in the same twinkle, handle the situation. The coordination isn’t there anymore. No one knows that better than I do.” http://www.secondsout.com/columns/thomas-hauser/sugar-ray-robinson-revisited--part-two