SUDOKU PUZZLES WITH ANSWERS DRIVER

There are a number of potential Step 6 clues, but none of them track through the puzzle, such that no unsolved cells are affected by both driver cells. We will start by searching the 1’s to see if there is a potential Step 6 clue, and then navigate through the 2-9’s.

Look for just 2 unsolved cells in a row that contain the same option where these 2 cells are not in the same box.

Look for just 2 unsolved cells in a column that contain the same option where these 2 cells are not in the same box.

Look for just 2 unsolved cells in a box that contain the same option where these 2 cells are not in the same row or column.

There are 3 circumstances that establish the potential for a Step 6 exercise: There are no Step 1-5 clues, so we will now proceed to Step 6: Dan’s Yes-No Challenge. Now your grid should look like Example #60.3 below. We have now completed Puzzle Preparation steps 1-4, so we will fill in the options for the unsolved cells. Now your grid should look like Example #60.2 below: Example #60.2 The only cells in box 2 that can be a 7 are C4R2 & C5R2, so put a small 7 in the bottom of C1R2, C2R2, C8R2 & C9R2. The only cells in box 6 that can be a 5 are C7R6 & C8R6, so put a small 5 in the bottom of C4R6 & C6R6. The only cells in box 2 that can be a 4 are C6R1 & C6R3, so put a small 4 inn the bottom of C6R4, C6R6, C6R8 & C6R9. The only cells in box 4 that can be a 3 are C1R4 & C2R4, so put a small 3 in the bottom of C4R4 & C9R4. The only cells in box 9 that can be a 2 are C8R8 and C9R8, so put a small 2 in C4R8, C5R8 & C6R8. Indicate by placing a small 1 in the bottom of C3R3. (A 1 cannot exist in C3R1, C3R8 or C3R9, but we already know this). The only cells in box 4 (left-hand middle box of 9 x 9 cells) that can be a 1 are C3R5 & C3R6 therefore, a 1 cannot exist in C3R3. Now your grid should like Example #60.1 below: Example #60.1 The first thing we observe is that C2R6 (cell in column 2, row 6) =2 (obvious answer).

We will start with the 1’s and navigate through 2’s to 9’s, then repeat the process until we conclude all step 1-4 clues. This month we will again complete all of the first 4 steps in the order we observe them, versus all step 1, then step 2, step 3, and step 4 in order, before we move on to step 5. FILL IN THE OPTIONS FOR THE UNSOLVED CELLS MARK UNSOLVED CELLS WITH OPTIONS THAT CANNOT EXIST INTHOSE CELLS.ĥ. Prior to utilizing techniques first complete the 5 Steps of Puzzle Preparation …Ĥ. More on this technique later in the puzzle. It is by far the most difficult puzzle ever presented in my monthly articles (assuming I did not miss a clue)! To solve this puzzle, we will employ a new (to this magazine) technique that rarely needs to be used. Puzzle #60 represents a unique experience. If we say 7 saves 6, those of you who have been following my articles will probably realize the meaning! Steps 6-8 are covered in detail, in Dan’s book. Steps 1-5 are relatively common techniques and are explained in the TI LIFE articles above. Step 7: DAN’S CLOSE RELATIONSHIP CHALLENGE Step 4: XY-Wings & XYZ Wings – See December 2015 Step 3: Sudoku Gordonian Rectangles and Polygons – See November 2015 Step 2: Turbos & Interaction – See October 2015 Step 1: Sudoku Pairs, Triplets and Quads – See September 2015 Once you have completed the puzzle, to the extent that you have filled-in all obvious answers and have written all potential options across the top of the unsolved cells (PUZZLE PREPARATION), Dan recommends the following Steps to complete the puzzle. There is a place at the end of this article to weigh in on your thoughts, should you care to express them.ĭAN’S 8-STEP APPROACH TO SOLVING ALL SUDOKU PUZZLES Perhaps that is not what you are seeking, but if you learn to solve the puzzles in my articles, you will have the skills to solve any Sudoku puzzle. Each morning I solve on the average three 17-given puzzles, looking for the one that can possibly assist you in sharpening your Sudoku skills. Quite simply I seek the most difficult puzzles I can locate. Ok, so why 17 each month? As you know by now, there is a monthly puzzle which you can solve on your own, or you can follow my lead. Most likely any puzzle with 16 given answers will have more than one solution. We say “valid” meaning there can only be one solution for a puzzle. Additionally, there is belief that no valid Sudoku puzzles can contain only 16 given answers. Why does the author choose a puzzle each month with 17 given answers? Going back in time I read that valid Sudoku puzzles must have a minimum of 17 given answers, and the maximum is debatable, usually in the 30’s. You may wonder about the puzzle selection for this magazine.

Sudoku puzzles with answers