His 1955 memoir — called “The Four-Minute Mile,” and reissued 50 years later as “The First Four Minutes” — amounted to a portrait of the athlete as a young artist. In a typically analytic and introspective passage, he described the moment at which a runner decides to break from the pack and take the lead:

“The decision to ‘break away’ results from a mixture of confidence and lack of it. The ‘breaker’ is confident to the extent that he suddenly decides the speed has become slower than he can himself sustain to the finish. Hence he can accelerate suddenly and maintain his new speed to the tape. But he also lacks confidence, feeling that unless he makes a move now, everyone else will do so and he will be left standing.

“The spurt is extremely wasteful because it is achieved at the cost of relaxation,” he went on, “which should be maintained throughout the race. The athlete’s style and mood change completely when he accelerates. His mind suddenly starts driving an unwilling body which only obeys under the stimulus of the excitement. The earlier in the race this extra energy is thrown in, the greater the lead captured, but the less chance of holding it.”

The idea at the heart of this passage — that you must seize the right moment or risk its passing forever — was very much a factor in Bannister’s record-setting run. Milers had been flirting with four minutes for at least a decade. The Swedish runner Arne Andersson ran a 4:01.6 in 1944; the next year, his countryman Gunder Hägg sliced two-tenths of a second from the world record.

It had gone no lower before Bannister toed the starting line at Iffley Road, but it was widely believed that the four-minute barrier was on the verge of falling, and that one of three men — Bannister, the Australian John Landy and the American Wes Santee — would bring it down. (Landy became the second to do so; Santee never did.)