Bob
Back in the day, I recall plenty of people who made multiple attempts, plenty way "better" than me and who shall remain nameless.
I just wonder if the proliferation of ultra events of one sort or another may have something to do with the lack of second and subsequent attempts. Back in 1985 (my year) other options were more limited, so that may have driven a greater desire to make multiple attempts. The BG wasn't the only game in town, but you get my logic.
Fred always reckoned that the success rate was 1 in 3 and between 1970 and 1978 he crunched the data to a ridiculously detailed degree. Hence the language on the website. The weather can be a great leveller and if it carries on pissing down at current rates, the rate will be back down at 33% before we know it.