This is super interesting! Thank you @PetAccount 
Two things I notice:
- Relatively few beginners (20-30 kyu). Is this because we genuinely don’t have many beginners? In which case discussions of how to be more welcoming to beginners (e.g. Glicko-2 does not require accounts to start at 12 kyu. So why do we do that?) are maybe not as important as we thought. Or is this because:
and OGS is so unwelcoming to beginners that few survive? In which case, those discussions are even more important.
- There appears to be a steep drop from 2 kyu to 1 kyu and from 1 kyu to 1 dan. Why is this?
Maybe there is some great leap in how players think about their game that is necessary to break through these levels that makes it inherently more difficult than progressing at lower levels. Or maybe, so many SDKs striving for shodan get annoyed being stuck at 2-5 kyu that they get demotivated to put the effort in to keep improving. Or a bit of both. Or something else… 
Anyway, cool plot. Thanks again 