[About D Levels]What are they exactly?

[Nick012]

I use this spreadsheet to see what level of play each division requires:
https://docs.google.com/spreadsheets...64829&vpid=I66
Not sure if it´s approved by the FFR community.

Another system used to define how hard a song is is the smleaderboards algorithm (which i think is rather new, not complete and not as accepted as divisions)
http://smleaderboards.net/home