March Sudoku Puzzles #141, #142, #143, & #144

By: Dan LeKander

Volume 18, Issue 3, March 2023

Spring is only days away.  Let’s clean out the cobwebs and solve the Sudoku challenges this month!


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 #141?

Puzzle #141

(The answer follows the conclusion of Puzzle #144, the feature puzzle for this month)

Just Logic Puzzle

Difficult rating … 7/10
(Rating based on puzzles not requiring advanced techniques)

Puzzle #142

Hint … be relentless searching for clues.

Impossible to solve?

Impossible?  No.  Difficult?  Extremely.  

Puzzle #143 should be quite a challenge.  Advanced Techniques (Steps 6 and/or 7) are required.  Difficult rating 9.5/10.

Puzzle #143

Feature Puzzle

Difficult rating …  3/10
(Rating based on puzzles requiring advanced techniques)

Puzzle #144


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


The first thing we observe is that C1R4=1.  C5R9=1.
C7R1 & C7R3 have options 5 & 8.

In box four a 5 can only exist as an option in C2R4 and C2R5; therefore, a 5 cannot exist as an op-tion in C2R1, C2R3, C2R8 and C2R9.

In row six C1R6, C2R6, C3R6 & C6R6 are limited to options 2, 4, 7 & 8.  Then, C5R6, C7R6 & C9R6 are limited to options 3, 6 & 9.  Since a 3 and 9 already exist in column 9, C9R6=6.

Ok, let’s pause here to explain a technique used to identify situations like this that frequently appear.  If you look at row six, you know that one of the given answers (1) matches the 1 in box four.  Look for a column associated with row 6 that might have three of the other given numbers in box four.  Yes, in this case there is a 3, 6 & 9 in column six.  Bingo, we have detected a quad in row six, and in this case, we know we have a triplet in row six as well.  Ponder on this and work it out in your mind how to easily recognize these situations.

C5R6 & C7R6 have options 3 & 9.

In box eight a 5 can only exist as an option in C5R7 and C6R7; therefore, a 5 cannot exist as an option in C1R7, C3R7 & C9R7.

Now your grid should look like Example #144.1 below:

Example #144.1

Please note:  options for C6R6 are limited to 2 & 4.  The 7 is eliminated as an option by C6R4.  The 8 is limited by C1R6 & C3R6 being the only two cells in box four that can be an 8.

This completes Puzzle Preparation Steps 1-4.  

Normally, next we would fill in options for all of the unsolved cells.  However, there are two options that would make excellent candidates for Step 6 exercises.

As in previous articles, we determined a particular number was a potential for a successful Step 6 exercise if that number appears as a given answer in 3 separate boxes, such that the boxes are not side-by-side, nor over each other.  Which numbers do you see that are good candidates?   Yes, the 3’s & 9’s.  We do not need the options of the unsolved cells to be listed in order to con-duct these exercises.  If one or both of these exercises is successful, we could save quite a bit of time not having to fill in the options for all unsolved cells and potentially shortening the time to solve the puzzle.

We will start with the 3’s and perform a Step 6 exercise, Dan’s Yes-No Challenge”, per Example #144.2 below, using C1R2 & C5R2 as our starter cells highlighted in yellow.

Example #144.2

Either C1R2 or C5R2 has to be a 3.   First, we will assume C1R2=3 and mark it with a capital Y, for yes.  Then we will mark the cells it affects in other boxes with a Y or N, indicating a yes or no.

Next, we will assume C5R2=5, and mark it with a “y”.  Then we will mark the cells it affects with a y or n.

Example #144.3

We see that C1R7, C7R8 & C8R5 are marked N,n.  It means that these cells cannot be a 3, regardless of which starter cell is a 3.  The 3 can be eliminated as an option for those cells.  We also see that C8R7 is marked with a Y,y, meaning that cell is a 3 regardless of which starting cell is a 3; therefore, C8R7=3.

Now our grid should look like Example #144.4 below:

Example #144.4

We can now see that a 9 can only exist as an option in box 9 in C7R9 and C8R9; therefore a 9 cannot exist as an option in C2R9 & C3R9.  Thus, C3R7=9.  C2R1=9.

C5R2=9 and so forth.  It is downhill from here, leading us to an easy conclusion, as per Example # 144.5 below.

Example #144.5

May the gentle winds of Sudoku be at your back.

By Dan LeKander

Clue for Puzzle #141 …  did you find the clue?  If not, read on.

Check column 9.  What do you see?

We see that C9R3, C9R5 & C9R6 are the only three cells in row 3 that can have options 4, 5 & 8.  Since there already exists a 4 & 8 in row 6, C9R6=5.

Important Editor's Note

We need to hear from you - do you work on Dan's Sudoku's Puzzles

Dan would like to hear more from his readers, such as questions, comments & suggestions.  To confidentially reach Dan please e-mail him to this link -  We will forward this to Dan, and he will contact you directly.  Thank you."

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

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

Here are links to all past Sudoku Puzzle Challenge beginning: February 2016, March 2016, April 2016, May 2016, June 2016, July 2016, August 2016, September 2016, October 2016, November 2016, December 2016, January 2017, February 2017, March 2017, April 2017, May 2017, June 2017, July 2017, August 2017, September 2017, October 2017, November 2017, December 2017, January 2018, February 2018, March 2018, April 2018, May 2018, June 2018, July 2018, August 2018, September 2018, October 2018, November 2018, December 2018, January 2019, February 2019, March 2019, April 2019, May 2019, June 2019, July 2019, August 2019, September 2019, October 2019, November 2019, December 2019, January 2020, February 2020, April 2020, May 2020,  June 2020 and July 2020, August 2020,  September 2020, October 2020, November 2020 and December 2020, January 2021, February 2021, March 2021, April 2021, May 2021, June 2021, July 2021 , August 2021, September 2021 ,  October 2021, November 2021, December 2021, January 2022, February 2022, March 2022, April 2022 , May 2022, June 2022, July 2022 , August 2022, September 2022, October 2022, November 2022, December 2022, January 2023 and February 2023

Posted in: Volume 18, Issue 3, March 2023, Sports

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