Any guy that focuses on 400m instead of 1500 will be faster at 400m, and when they run seldomly, the times are under estimated. For a one off, a faster 1500m athlete will be pressed to run 49 or under 50 secs 400m in the midst of a training cycle, and 48 seconds is a great result when peaking. The PR of these guys say running just a season as a 400m runner, the opener will be 1 1/2 seconds off peak, and the above are the considerations when people speculate about the 400m time.
Guys like Cram say they are hard pressed to run a 48, this would be true, but that doesn't tell the real tale and hides the truth, where that 48 speed means 142 800m,
Out of the blocks, and peaked for 800m,
Ryun, he was 46 low, Coe 45 high, Ovett 46 high, Walker 48 flat, Doubell 46x, Hocker 48 flat, Cram 48 flat.
Coe, Ryun, Doubell, Ovett could have managed to be 400m runners, not world class but international class. which is kind of obvious, given their WR
performance in the next event up.