This is why I come to the internet.

Very nice!

I wonder if the author can do a Parker Football?

https://www.mathsballs.com/

Stumbled on this, an absolutely fascinating exposition on crafting bean bags for juggling/footbagging. Well structured & written, hundreds of pages of pdf's.

On the meta, there's a bittersweet feeling - discovering these "early internet" (i.e. pre-enshittification/sloppification) gems is an increasingly rare experience.