Change grade band chart for style "unknown"

[georg-d]

At https://www.thecrag.com/climbing/italy/monte-campo-dei-fiori the grade band chart is shown in grading system YDS while crag's grade context is FR and all routes are in FR. In such case, I'd expect the histogram to be shown in same grading system as the routes.

More detailed why I consider it as issue, how wide spread it is and whether we shall do something about it:

• I value this as unexpected/bug because of help description
• If crag's grade context is FR and all routes are FR, to my eyes it's artificial/odd to convert all routes to YDS for display in grade band chart – and it makes the chart mostly useless for the vast majority of users that may ever climb at that crag: YDS is so extremely uncommon throughout central Europe that many Europeans climbing for even 10+ years don't have a vague feeling which YDS grade means which difficulty. For experienced theCrag users, the best guess is "there are no red bars in the chart so everything has to be easier than FR 7b".
• It works fine for all other crags in the area I looked at.
• According to comment in #3046 the reason seems not to be an issue with grade context, but that all routes have unknown climbing style
• I wanted to look up how many crags satisfy the assumed issue conditions, but was not successful to create a query "crags with only routes of style unknown". But search for routes with style = unkown provides >10.000 results alone in Europe, so the mentioned crag is likely not an extreme edge case.
• Over the years, when people improve the database, style unknown will vanish more and more, so will the issue.

[rouletout]

Plan is to not show the grade band when it is all unknown to encourage data entry.

[georg-d]

While I'd personally prefer another approach, I understand the motivation and go with your approach as it's better for the site in the long term. To help people doing the right thing, IMHO we shall display a message like "Can't show grade band chart because route style is still unknown, thus also the correct grading system." where the grade histogram is (maybe message above an empty, half transparent histogram?).

[rouletout]

That's a nice idea :-)