Latest Changes and Additions

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

What's New
Date Created: Monday 17-Aug-2009
Last Updated: Monday 10-Feb-2025


WXYZ-Wing
Date Created: Friday 11-Apr-2008
Last Updated: Monday 10-Feb-2025
Sudoku Strategy. WXYZ-Wings extend XYZ-Wings to four numbers and are four cell formations used to eliminate candidate elsewhere. They use a common candidate method to find contradictions.

KenKen Parity Strategy
Date Created: Wednesday 1-Jan-2025
Last Updated: Saturday 1-Feb-2025
KenKen 6x6 strategy that uses ODD/EVEN parities to determine eliminations

Chute Remote Pairs
Date Created: Friday 24-Jan-2025
Last Updated: Thursday 30-Jan-2025
A simple pattern to try early on

Gurths Theorem
Date Created: Saturday 28-Sep-2019
Last Updated: Saturday 25-Jan-2025
Gurth's Symmetrical Placement Theory is discussed

Cage Unit Overlap
Date Created: Tuesday 22-Mar-2011
Last Updated: Tuesday 7-Jan-2025
Killer Sudoku Strategy. Cage Unit Overlap looks at the intersection of a cage with a row, column or box to find eliminations.

Unique Rectangles
Date Created: Friday 11-Apr-2008
Last Updated: Sunday 5-Jan-2025
Sudoku Strategy. Unique Rectangles takes advantage of the fact that published Sudokus have only one solution. There are many formations and strategies based on this notion and they are explained here.

Alternating Inference Chains
Date Created: Saturday 12-Apr-2008
Last Updated: Sunday 5-Jan-2025
Sudoku Strategy.Alternating Inference Chains are explained. This is the fundamental chaining strategy used to find eliminations on cells that can see the start and end of a chain.

Hidden Unique Rectangles
Date Created: Wednesday 23-Apr-2008
Last Updated: Sunday 5-Jan-2025
Sudoku Strategy. Hidden Unique Rectangles extends Unique Rectangles that take advantage of the fact that published Sudokus have only one solution. Formations and strategies based on this notion and are explained here.

Jigsaw Sudoku Player
Date Created: Wednesday 20-Nov-2024
Last Updated: Wednesday 20-Nov-2024