I am rereading Annapurna by Maurice Herzog, the account of the first successful ascent of an eight-thousander, which took place in 1950.
In Chapter VII, the following dialog takes place:
[Lachenal, just returned from a reconnaissance]: There are pitches which are easily Grade Five. [Herzog]: Grade Five! ,,,, How on earth do you think Sherpas can climb pitches of that grade? ...... We can fix ropes and by pulling and pushing the Sherpas we'll manage all right.
How did Sherpa climbing evolve from their being "pulled and pushed" to their equality in skill and even pulling and pushing expedition "members" themselves? (For example, Lobsang short-roping Pittman on Everest? Of course, that was no Grade Five.) For some, the equality must have been reached by the time of Hillary's and Norgay's climb, but when and how did reliance on Sherpa technical skills become the norm?
Or was Herzog's evaluation incorrect?