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Latest Changes and Additions

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

Sudoku Solver for Android
Date Created: Saturday 15-Dec-2012
Last Updated: Sunday 26-Nov-2017

Empty Rectangles
Date Created: Saturday 12-Apr-2008
Last Updated: Sunday 26-Nov-2017
Sudoku Strategy. Empty Rectangles is a complex strategy that uses a variety of formations and the fact that a Sudoku puzzle should have a unique solution.

Grouped X-Cycles
Date Created: Saturday 12-Apr-2008
Last Updated: Friday 24-Nov-2017
Sudoku Strategy. All chains used in Alternating Inference Chains strategies can take advantage of grouped cells for the purpose of finding links. This explains how.

Sudoku Solver - Version History
Date Created: Sunday 13-Apr-2008
Last Updated: Friday 8-Sep-2017

Hidden Candidates
Date Created: Wednesday 9-Apr-2008
Last Updated: Tuesday 24-Jan-2017
Sudoku Strategy. Hidden Pairs, Triples and so on - these are the candidates in cells aligned on a row, column and box which can be used to remove other candidates the formation is aligned with.

Naked Candidates
Date Created: Thursday 9-Jun-2005
Last Updated: Tuesday 24-Jan-2017
Sudoku Strategy. Naked Pairs, Triples and so on - these are the remaining candidates left in cells aligned on a row, column and box which can be used to remove other candidates the formation is aligned with.

Exocet
Date Created: Wednesday 26-Oct-2016
Last Updated: Monday 9-Jan-2017

Double Exocet
Date Created: Sunday 4-Dec-2016
Last Updated: Sunday 4-Dec-2016
Sudoku Strategy: Very powerful elimination sets can be deduced from the overlap of two Exocet patterns

What's New
Date Created: Monday 17-Aug-2009
Last Updated: Sunday 4-Dec-2016

Unique Rectangles
Date Created: Friday 11-Apr-2008
Last Updated: Sunday 27-Nov-2016
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.