allow slash grades between numbers

I think we should be able to grade a route 10d/11a or 11d/12a or 12d/13a etc.

I mean, i have never been on a 10d that was easier than 11a, so this whole idea sounds silly to me personally.

Or better, let's add +/- to letter grades.  because the YDS systems isn't silly enough...

No

Slash grades introduce unnecessary confusion because there is not one single understood meaning. Both YDS and French systems already have sufficient granularity for most contexts.

I liked the old school 10-, 10, 10+ system. Seemed to allow for a little ambiguity between the grades without having to nail things down so hard. 

Iz K wrote:

How would you treat .9+? Is it .9+/.10a or .10a/.9+?

9/10d