I noticed an inconsistency with the grade conversion between British adjectival and British technical grades.
Apologies in advance for the length of this post, but that is the wonderful world of British grades.
First, a quick summary: The adjectival grade takes into account all factors including technical difficulty, gear, safety etc - much like Ewbanks. The technical grade is just for technical difficulty, but when taken in context with the adjectival grade, you can get an understanding of how bold or safe the climb is. Furthermore, the tech grade is (basically always) within an agreed range for each adjectival grade, which you can see in the following chart:
So for VS (Very Severe) climbs have technical grades of 4a-4c, where 4a is easier but bold and 4c harder but better protected. If we assume a ’normal’ route is not especially bold or safe, then the expected or normal technical grade would be the midpoint of the range, (or thereabouts), in this case, 4b.
However, if you try to convert VS to British technical you get 5a (which is basically an impossibility because Vs 5a doesn’t really exist as a grade).
And the difference between 4b and 5a is actually quite a lot (maybe more than 4 Ewbanks grades at that difficulty).
NB: you do occasionally find a route with a technical grade outside of the usual range (usually higher). As an example, a route where there is one very hard (but safe) move off the ground, and then easy climbing above. However these are very much outliers, so can be ignored for the current purpose.
Now we can all argue about how one grading system converts to another and it is never going to be perfect etc. But, what I have described above is a logical mistake which is distorting grade conversion - and by a lot, in the grade range of the average climber.
Simon noted that it was a known limitation with British adjectival grade conversion, and that it stemmed from not having the agreed grade ranges for each adjectival grade.
Rockfax is probably the most prominent publisher of guidebooks in the UK, so I don't see a reason not to use those grade ranges for grades HS and up.
I noticed an inconsistency with the grade conversion between British adjectival and British technical grades.
Apologies in advance for the length of this post, but that is the wonderful world of British grades.
First, a quick summary: The adjectival grade takes into account all factors including technical difficulty, gear, safety etc - much like Ewbanks. The technical grade is just for technical difficulty, but when taken in context with the adjectival grade, you can get an understanding of how bold or safe the climb is. Furthermore, the tech grade is (basically always) within an agreed range for each adjectival grade, which you can see in the following chart:
So for VS (Very Severe) climbs have technical grades of 4a-4c, where 4a is easier but bold and 4c harder but better protected. If we assume a ’normal’ route is not especially bold or safe, then the expected or normal technical grade would be the midpoint of the range, (or thereabouts), in this case, 4b.
However, if you try to convert VS to British technical you get 5a (which is basically an impossibility because Vs 5a doesn’t really exist as a grade).
And the difference between 4b and 5a is actually quite a lot (maybe more than 4 Ewbanks grades at that difficulty).
NB: you do occasionally find a route with a technical grade outside of the usual range (usually higher). As an example, a route where there is one very hard (but safe) move off the ground, and then easy climbing above. However these are very much outliers, so can be ignored for the current purpose.
Now we can all argue about how one grading system converts to another and it is never going to be perfect etc. But, what I have described above is a logical mistake which is distorting grade conversion - and by a lot, in the grade range of the average climber.
Simon noted that it was a known limitation with British adjectival grade conversion, and that it stemmed from not having the agreed grade ranges for each adjectival grade.
Rockfax is probably the most prominent publisher of guidebooks in the UK, so I don't see a reason not to use those grade ranges for grades HS and up.