In reply to Robert Durran:
> (In reply to Offwidth)
> [...]
>
> No, I just want you to tell me what the YDS grade measures.
All explained above Robert. It's complicated and it depends:
Roger Breedlove can always be counted on to provide a comprehensive answer
Hi Mick,
Your question on which logic, the hardest move versus overall difficulty, is used in the YDS is not commonly agreed, based on nothing more than the posts and links on this thread.
While a system could be based on either set of rules, at least from the early 1960s the YDS system has been based on the rating for the hardest section, not hardest move. This way of thinking about ratings is not meaningful to climbers until the climbing gets hard: nobody calls a sustained 5.3 pitch anything other than 5.3. As such, I don't think that climbers in the 50s had much need for sustained difficulty ratings. (There may be a different history in Tahquitz in the 1050s with regard to sustained ratings, so I'll only refer to the Valley.)
With this line of thinking, I suppose it would be strictly correct that originally the YDS was based on hardest move logic. However, once there was a need for ratings based on the hardest section, once the climbing was both hard and sustained, the evidence say hardest section logic was adopted as a natural course—there doesn’t seem to have been any point of discussion, at least in Roper’s guide book. Up until about 1963, most Valley climbers started nailing when the free climbing became hard. (One has only to look at Frank Sacherer's stellar run of FFAs in 1963-65 to see the truth in this: all those climbs he did free were originally nailed.) In this sense, ratings for sustained climbing have always been part of the guide book ratings in Yosemite. This is contrary to what is in the Wikipedia article and in several of the posts upthread.
The first piece of evidence for this is stated explicitly in the Roper’s 1964 guide. Dave posted a scan of page 29, but it is worth listing the elements that Steve states should be included in the rating.
1. The difficulty on the most difficult technical free-climbing section
2. The most difficult aid section
3. The strenuousness of the climb
4. The Continuity of the climb
5. The mental problems encountered (such as lack of protection, loose rock, exposure)
6. The length of the route
7. The approach and descent required
8. The weather
Steve adds that there are probably several more.
The YDS was at that time made of three numbers:
One for the most difficult technical free-climbing section (Class 1-5)
One for the most difficult technical direct-aid section (Class 6)
One for overall difficulty (Grade)
In every instance when Steve could have stated "hardest move", he instead states "hardest section." This is about as clear as it gets that, at least in 1963-64 when Steve was writing his first guide, the YDS incorporated logic for the higher ratings for sustained sections. The next piece of evidence is to look at the actual ratings that were applied to routes in the Valley when hard, sustained pitches became more common place. The second pitch of Reeds is the most obvious example, as Peter points out in his post. (I think that Peter makes the same argument as I do here.) I have tried to reconstruct climbs in the 50s and early 60s that were hard and sustained. In 1956, The Arrowhead Arête, first climbed by Mark Powell, was considered the most sustained 5th class climb in the Valley but it is 5.8, when the highest standard was then 5.9. In 1960, Pratt climbed The Crack of Doom, which he rated 5.10. Maybe someone can remember if this was a pitch rating—-lots of unprotected 5.9—-or a single move. For the most part, sustained 5th class climbing did not become common place until Sacherer and Pratt focused on all-free ascents in 1964, just about the time that Steve was writing his guide book.
From memory, this is also the way that ratings were applied to aid climbing with a clear sense that A5 was what you got if you linked a bunch of A4 placements.
In Bridwell’s 1973 article in Ascent, introducing the a,b,c,d system to 5.10 and above ratings, he clearly articulates the newness, and in his opinion the stupidity, of hardest move ratings. In his take no prisoners style:
The most common motivation behind downrating is protection of the downrater's self-image. Avoid the ridicule of having one's climb downrated. Downrate first and be safe. This type of game causes its most dedicated players to fool even themselves. Move rating is an outgrowth of this syndrome. Breaking a pitch into individual moves and rating the pitch by the hardest move is nonsense. A hundred foot lieback with no moves over 5.9, but none under 5.8, and with no place to rest, is not a 5.9 pitch!
I don’t really understand where the notion that YDS is based on hardest move logic comes from. I don't know if it is a holdover from someone who believed that the guide book writers had it wrong or if it is a newer construction without any historical basis. I personally have never seen any justification for this idea on a historical basis, although I have heard lots of arguments from individuals. I can remember that in the late 60s and early 70s, the Steck-Salathe was widely considered to be just barely 5.9 since there didn’t seem to be any moves harder than 5.8. (The rock has changed since and there are now sections that are considered 5.10 in themselves.)
Part of the arguments about ratings are based on climbers not being comfortable with consensus driven comparative ratings; it all seems so squishy and there are always quotes from famous climbers disputing the ratings in the guide book for particular climbs. In the early 1960’s, Frank Sacherer had a reputation for under rating free climbs, but sometimes this was because he under rated specific moves rather than following a logic of only rated the hardest move: he rated just about all of his climbs 5.9.