Bosi: Mutation 9a+ or 9b?

William Bosi just did the first repeat of Steve McClures's 9a Mutation at Raven Tor from 1998. Bosi has recorded it as a 9a+ although media has speculated it to be 9b.

What grade would you have given Mutation if it was your FA?
So when you make a first ascent it’s always much harder to grade than just repeating a route. The most useful thing you can do is compare it to the other routes at the crag. I haven’t actually tried a lot of the other hard routes at Ravens Tor. However, if I was able to send them not too bad I would definitely be grading it (Mutation) at least 9a+ as skipping 9a would seem reasonable. If I were to give it the 9b as FA when I’m not sure I have the best beta/it doesn’t suit me perfectly I would need the other 8c+s at the crag to go down in a day/couple attempts. So I reckon I would have gone with 9a+.

How would you rank Mutation among the hardest route you have ever done?
King Capella 9b+ FA
La Capella 9b
Mutation 9a+
Furia de jubali 9b FA
First ley 9a+

So personally that order makes sense to me as La Furia suited my style really well and although the climbing was technically more difficult, I felt I could power through the moves when I was feeling good. On Mutation, 'powering through' was not an option, whilst the moves themselves were in themselves easier, each move had to be technically 100% correct and it all had to come together on one attempt which made the ascent more tricky for me.

This just goes to show the difficulties on grading at the top level where (a) it is completely subjective and (b) there as so many factors at play which go into your own individual experience of the route which goes back to one of my earlier comments that hopefully, further ascents will help to attain some consensus.