I tend to look at the 24 Hour distances of the riders. Comparing John Barkman with John Warnock is interesting. The top 24 hour riders can be assumed to be out for a time, and what they do at PBP is revealing of the factors governing that.
At the other end of the field, it can be seen that there are plenty of younger entrants who take close to 90 hours.
I also like to compare the data with narrative accounts, to see where the wheels come off a ride, and why. That tends to make me favour the writing of the people I've met, so I can give the appropriate weight to what they say. That's a difficult area for newcomers, as they can't always judge who to take seriously.