The archive here has a great lot of info on results of US Nationals:
http://www.trackandfieldnews.com/index. ... ticles/979
It is a bit tricky to work out if the times are manual or FAT or something else.
I'll use the 200 meters men as an example. As usual, times to two decimal places can be reasonably taken as FAT - they are all two decimal places from 1978 onwards and I assume that the early times with one decimal place are manual, up to 1953.
The problem is in the 1954 to 1977 period, where it is not clear what timing method is used.
In 1962, 1963 and 1966 there are two sets of times given, looking like a manual time and a FAT time, where the difference between the two is roughly what you would expect - the standard 0.15-0.25 range, although some of the differences in 1966 are a bit small.
In 1973 there are also two sets of times, but the second set, with two decimal places, are only around 0.05 slower than the first set of one decimal places. I suspect that these are actually FAT times converted to times which have the appearance of manual times, similar to what was done at the 1964 Olympics: subtract 0.05 and round to the nearest decimal place.
I suspect that this is also what has happened for the 1974 and 1977 times, which are also given to one decimal place but have no other info, plus a few years earlier than 1973 as well.
In 1968 and 1969, two sets of times are given as well, but both have only one decimal place and the second set is actually faster than the first set! I think that the first set of times are FAT or something like FAT, and the second set is actually the manual times. Can anyone verify that?
Finally, the times in 1954 and 1956 have one decimal place for the winner but then two decimal places for everyone else. I suspect that these are cases where the winning time is manual but the photo was studied for the margins, which could be then determined more accurately, or was there a FAT or pseudo-FAT (Bulova?) system in place?
The 1964 and 1965 times (and 1957-61) look like manual times, but I am really unsure of that given the above thoughts.
Thanks in advance for any answers on this!