# Sudoku Puzzles #169, #170, #171 & #172

### By: Dan LeKander

Volume 18, Issue 10, October 2023

Welcome to another month of something-for-every Sudoku enthusiast.

### Clueless?

We start with a Sudoku puzzle in progress, where it appears that there are no more obvious or not-so-obvious clues.  Can you find the hidden clue in Puzzle #169?

(The answer follows the conclusion of Puzzle #172, the feature puzzle for this month)

### Simply a Logic Puzzle

Difficult rating … 8/10
(Rating based on puzzles not requiring advanced techniques)

### Impossible to solve?

Impossible?  No.  Difficult?  Extremely.

Puzzle #171 will be challenge for you.  Advanced Techniques (Steps 6 and/or 7) are required.  Difficult rating 10/10.

### Feature Puzzle

Difficult rating … 4/10
(Rating based on puzzles requiring advanced techniques)

### PUZZLE PREPARATION

Prior to utilizing techniques 1-8, complete the 5 Steps of Puzzle Preparation …

1. FILL IN DATA FROM OBSERVATIONS
4. MARK UNSOLVED CELLS WITH OPTIONS THAT CANNOT EXIST IN THOSE CELLS
5. FILL IN THE OPTIONS FOR THE UNSOLVED CELLS

(hint … If you need a refresher on Step 6, please click the April 2023 issue)

May the gentle winds of Sudoku be at your back,

Dan LeKander

Clue for Puzzle #169 …  did you find the clue?  If not, read on.
C4R1, C4R2 & C4R3 are limited to options 2, 4 & 6; therefore, C4R5, C4R6, C4R7 & C4R9 are limited to options 1, 3, 5 & 9.  There is already a 1, 5 & 9 in row 6; therefore, C4R6=3.
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Editor’s Note:  Dan would like to hear more from his readers regarding questions, comments and suggestions.  To confidentially reach Dan, please e-mail him at this address … info@thousandislandslife.com

Recently someone wrote to ask how to fill them out online. Unfortunately, you need to print them yourself,  but that is easy to do and I know you will have just as much fun. Also you can use a grid sheet and copy numbers onto the grid.

And, if you have not already done so, I suggest you purchase Dan’s book: “3 Advanced Sudoku Techniques, That Will Change Your Game Forever!” Purchase of a book includes a 50-page blank grid pad, 33 black and two green tokens. The book is available by contacting info@thousandislandslife.com.

Be sure to read the TI Life's review of Dan's book by Jesse Kahn published in Jun 2015.

Posted in: Volume 18, Issue 10, October 2023, Sports