I would question that particular link. 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
- 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.