Month: April 2020

The German Sudoku Championship will take place online this weekend, which is a first if I remember correctly. I trust that the organizers, who are not to be envied for their responsibility in such troubled times, have done well with all the necessarity preparations. This post is not so much about the hosts of this particular event, but about hosts in general, and I also want to address a matter on the participants’ part.

There is a concept, a property of puzzle types instead of individual puzzles, which I have been studying for a while, and which I want to discuss today. I call it Rigidity. Let me explain what this is about.

Today’s post is about solution codes for puzzle contests, which appears to be a widely accepted tool to determine whether a solver has successfully completed a puzzle. Solution codes are a very delicate subject, and I want to make clear from the start that I do not have all the answers; I am just sharing a few thoughts here.