Where does the route setter know from which movements capabilities and
skills are assigned to each grade?
He doesn't. Skills != grade. Grade is a measure of difficulty.
You may find you prefer a particular type of climbing (say slabs or ones involving dynamic moves, etc). you have good skills in this area. This can make climbs of that style easier for you. But grades should ignore this fact. That's why it's better to get a range of opinions when grading.
Are there some general catalogues / guidelines which movements or
skills are necessary to master a certain grade?
No, grading is a subjective process. It's more art than science. There is no rules that say all v3s must be overhanging and use x size holds. It's purely down to how the route is set. Routes have different characteristics, these can make a climb more difficult or easier, but the route and characteristics of a climb are secondary to the grade. The grade purely exists to add a figure to the difficulty of the climb. i.e. a severely overhanging climb can be easy if it uses large well spaced holds or very difficult if it uses smaller difficult to reach holds.
Moreover, there are route setter certifications for local, national
and international level and a proper organization
Route setting and grading is different. You may set a route at 5.2 but following feedback you may change it's grade. It's common in indoor gyms to have a route feedback form. Outdoors route grades can and do change.
Also bear in mind a grade is typically a grade of the hardest one(or more) moves on a single climb. If 90% of the moves on a climb are 5+ but one move is 6a, the climb is graded 6a as that is the hardest part.
I'm going to reiterate some of the answer from Rating unorthodox climbs. This is a different question but the answer is pretty much identical.
Rating climbs isn't really a tick box exercise, for a start their are
multiple different grading
systems
all of which are slightly different.
You cannot say:
well it's at x angle and the hand holds are y size therefore it's w
There are a number of different challenges to grading climbs:
- Climbing grades are a rule of thumb and are open to interpretation.
- They are a measure of how hard it is to climb. Different people find different aspects of climbing more or less difficult so it is
always open to interpretation.
- Indoor grades are often very different to outdoor grades, bouldering gardes are very different to Trad grades, etc, etc.
- Grades tend to overlap so there is very little difference between a
5.9 and a 5.10a
- Height of climb, length of pitches, rock type, all need to be included in the grade. This makes comparing grades in different areas
difficult.
This is to the point that when a new climb is "put up" the grade that
the first climber gives it is a provisional one. This grade needs to
be confirmed by one or more climbers before it is accepted.
The best way to grade a climb is to gain experience of climbing well
know climbs that the grade is well known and accepted. Then when you
want to grade something that you don't know the grade for you need to
ask yourself (and others preferably) is this harder or easier than x
and y climbs? How much harder or easier? What about w climb? etc.
You'll likely never get it 100% right, people argue over grades
constantly. But the whole point is that it's impossible to get 100%
right. It's a guide only. You may find a V1 that's easy or a
completely different V1 that you find difficult.
