Latest Changes and Additions

A quick list of the latest updates and additions to this site:

Forcing Nets
Date Created: Monday 9-Mar-2026
Last Updated: Monday 6-Apr-2026
Explanation of Forcing Nets - an expansion of Forcing Chains using Alternating Inference Chains.

Simple Colouring
Date Created: Saturday 29-Jan-2011
Last Updated: Saturday 4-Apr-2026
Sudoku Strategy. Single's Chains, also known as Simple Colouring is a chaining strategy and part of a large family of such strategies. Cells and units with only two remaining candidates N are used to make links and find contradictions.

What's New
Date Created: Monday 17-Aug-2009
Last Updated: Friday 13-Mar-2026


BUG
Date Created: Friday 11-Apr-2008
Last Updated: Monday 9-Mar-2026
Sudoku Strategy. BUG stands for Bi-Value Universal Grave. It is a formation that relies on the uniqueness of the solution and an array of bi-value cells.

Cell Forcing Chains
Date Created: Saturday 6-Mar-2010
Last Updated: Monday 2-Mar-2026
Sudoku Strategy. This is a Forcing Chains Strategy. It finds eliminations by comparing the results of two chains starting with a bi-value cell assuming either candidate in the cell is turned on.

Death Blossom
Date Created: Friday 11-Apr-2008
Last Updated: Monday 2-Mar-2026
Sudoku Strategy. Death Blossom is based on extending Aligned Pair Exclusion but uses Almost Locked Sets to make some clever reductions. It is complex.

Avoidable Rectangles
Date Created: Sunday 13-Apr-2008
Last Updated: Sunday 1-Mar-2026
Sudoku Strategy. Avoidable Rectangles is a strategy which, uniquely among all strategies, relies on clues and solved cells rather than potential candidates.

Various Static Patterns
Date Created: Wednesday 14-May-2025
Last Updated: Sunday 1-Mar-2026


X-Cycles
Date Created: Saturday 12-Apr-2008
Last Updated: Wednesday 25-Feb-2026
Sudoku Strategy. X-Cycles are simple chaining strategies that stick to candidate N. They are Alternating Inference Chains based on following the consequences of turning candidates on and off.

X-Cycles (Part 2)
Date Created: Sunday 4-May-2008
Last Updated: Wednesday 25-Feb-2026
Sudoku Strategy continued. X-Cycles are simple chaining strategies that stick to candidate N. They are Alternating Inference Chains based on following the consequences of turning candidates on and off.