In reply to Moacs:
Surely there aren't enough grades, enough granularity to see the impact of any of those things. There will always have been outlying routes of a new given grade which for one reason or another significantly lead the wider spread establishment/acceptance of that grade. And then it'll be further messed up by the use of XS and HXS still being fairly common at the time of most of those innovations.
If you wanted to see the events/innovations align with trends I think you'd have to look at the rate of establishment of new routes at each grade (using their modern/settled grades) over time, I recon there you'd probably have enough signal to see through the noise. But of course you'd first need to find and/or digitise that data.
It's a limited dataset but if you were more than casually interested the Yorkshire Grit' guides would be a good starting point having a good history section and FA dates on the route entries. Thing is, for a single area I think you'll find the trends trace back to individual people/teams more than tech and ideas.
jk
Post edited at 14:17