Latest Changes and Additions

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

Daily Sudoku
Date Created: Saturday 12-Apr-2008
Last Updated: Sunday 8-Jun-2025
The Daily Sudoku puzzle by Andrew Stuart. This Sudoku can be completed directly on the web page - just enter numbers in the cells. Have fun!

X-Cycles
Date Created: Saturday 12-Apr-2008
Last Updated: Monday 26-May-2025
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.

Guardians
Date Created: Friday 11-Apr-2008
Last Updated: Sunday 25-May-2025
Sudoku Strategy (depreciated). Guardians is a complicated way of looking at what is ultimately a nice loop with off-chain eliminations.

Unit Forcing Chains
Date Created: Saturday 6-Mar-2010
Last Updated: Sunday 25-May-2025
Sudoku Strategy. This is a Forcing Chains Strategy. It finds eliminations by comparing the results of chains starting with all candidates N in a unit and assuming any of them are turned on.

Main Page
Date Created: Thursday 10-Apr-2008
Last Updated: Thursday 22-May-2025
Strategies for Sudoku, Sudoku X, Killer Sudoku and Jigsaw Sudoku - and the home of logical puzzle maker Andrew Stuart

Twinned XY-Chains
Date Created: Wednesday 14-May-2025
Last Updated: Wednesday 14-May-2025
Sudoku Twinned_XY_Chains invented by Nils Leder

Various Static Patterns
Date Created: Wednesday 14-May-2025
Last Updated: Wednesday 14-May-2025


20th Thank you
Date Created: Saturday 3-May-2025
Last Updated: Saturday 3-May-2025


Rule of 720 - With Divisors
Date Created: Thursday 1-May-2025
Last Updated: Thursday 1-May-2025


Not Allowed
Date Created: Monday 28-Apr-2025
Last Updated: Monday 28-Apr-2025
IFRAME embedding is not allowed