billablog

Here's a puzzle generated by Sudoku.Coach and posted by u/ddalbabo on Reddit. SC's "Beyond Hell" grids are always a treat, often on the very edge of requiring Forcing Chains.

  In this post I'll be tackling the weekly "Unsolvable" puzzle from  SudokuWiki . This week's puzzle was provided by Richard Kröger. 

I've been learning advanced Sudoku tactics for about 2 years now and lately I've been venturing into the world of branched AIC. It's very work-intensive to identify useful examples, but the results are equally rewarding.  2025-11-27 update: I've disowned this article in favour of  Almost-AIC as outlined in my AIC article . This article's conception of branching AIC was quite silly and admittedly motivated more by how pretty the graphs could be than by practicality.