The calendar feature is nice. I wanted to build my own schedule for the games I was interested in. There is full calendar that you can subscribe to as well, that gets updated as the fixtures get decided. I also wanted to be able to interactively change things and visualize the whole knockout stage.

All the state is in the URL fragment. It's a handrolled compact byte format. About 203 bytes, ~217 characters. The URL has the full snapshot so the link you share always renders the same brackets. It's versioned so I can change the format and not break links out there.

At this point it does everything I wanted it to do for me. Might be some real howlers in there. Let me know if you spot one.