Sorry, the whole “impossibility of 4 minute mile” / “4 minute mile effect” is a myth.
Bannister did his (successful) attempt in May 1954 because he knew John Landy (in particular, but also a few others) had set his sights on it and were getting close, and he thought (as Landy did too) that Landy would get it that year as soon as he got to Europe. They were both right—Landy did it 6 weeks later.
The reason the record had stayed just over 4 mins for so long was WWII interrupting athletics—Hagg and Andersson had got it down to 4:01.4 pretty quick between 1942-45. Sports folks at the time knew it was going to go.
”The claim that a four-minute mile was once thought to be impossible by “informed” observers was and is a widely propagated myth created by sportswriters and debunked by Bannister himself in his memoir, The Four Minute Mile (1955).” https://en.wikipedia.org/wiki/Roger_Bannister#Sub-4-minute_mile
Sorry, the whole “impossibility of 4 minute mile” / “4 minute mile effect” is a myth.
Bannister did his (successful) attempt in May 1954 because he knew John Landy (in particular, but also a few others) had set his sights on it and were getting close, and he thought (as Landy did too) that Landy would get it that year as soon as he got to Europe. They were both right—Landy did it 6 weeks later.
The reason the record had stayed just over 4 mins for so long was WWII interrupting athletics—Hagg and Andersson had got it down to 4:01.4 pretty quick between 1942-45. Sports folks at the time knew it was going to go.
”The claim that a four-minute mile was once thought to be impossible by “informed” observers was and is a widely propagated myth created by sportswriters and debunked by Bannister himself in his memoir, The Four Minute Mile (1955).”
https://en.wikipedia.org/wiki/Roger_Bannister#Sub-4-minute_mile
For more colour, see this article, which shows the same trend on the same timelines for a bunch of other distances—steady progress till 1940ish, a 10-15 year WW2 gap, then further steady progress mid 1950s on.
https://www.scienceofrunning.com/2017/05/the-roger-bannister-effect-the-myth-of-the-psychological-breakthrough.html?v=47e5dceea252