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Creative Sudoku Solutions
Registrace 27. 08. 2023
In these videos I share creative solutions to difficult Sudokus. These solutions mix imagination and intuition with reason and logic. I use a base method that allows me to see clearly all around the board. I call it the "only two cells" method. I mark places where there are only two cells in a given block where a given number can go. I find that this is sufficient to solve puzzles, and it really helps to have a clear board uncrowded with candidate numbers. [Update: Since starting this channel, I have learned that while I arrived at this method independently, it is actually known as Snyder Notation, after the solver who first practiced it, Thomas Snyder. Acknowledgments to him.] While developing these videos, I found myself moving into a further method, seeing Sudokus as nine interlocking number grids. This has enabled me to solve even more challenging and satisfying puzzles. The videos illustrate these methods.
(I am C.R. Smith, a longtime fan of Sudokus. Thanks for watching!)
(I am C.R. Smith, a longtime fan of Sudokus. Thanks for watching!)
37. ultra0313: Adjusting to a specific variation of a general pattern
This Sudoku is similar in design to h54autres_4 by champagne (video #34), Cloudy Bay by coloin (video #35), and ultra0203 by tarek (video #36). I was able to solve ultra0203 by supplying single numbers as one member of the key pairs of cells that were horizontal at the top and bottom of the grid (00:34 in video #36). In the case of this puzzle, that wasn’t possible, but it did work to supply single numbers in the key pairs of cells that were vertical at the left and right of the grid (00:29 in this video). So it seems that once we recognize a general pattern, we can make adjustments to address a specific variation of it.
zhlédnutí: 26
Video
36. ultra0203: Placing trigger numbers in key cells
zhlédnutí 17Před 21 hodinou
This Sudoku, ultra0203 by tarek, is very similar in design to Cloudy Bay by coloin (video #35) and h54autres_4 by champagne (video #34). In those puzzles, two pairs of “trigger” numbers are placed strategically among the givens so that certain pairs of cells-consisting of the middle cell of a block and a cell adjacent to it-must have one number from each pair. See, for example, 00:19 in video #...
35. Cloudy Bay: Analyzing a puzzle overall can help you recognize what tactics to use
zhlédnutí 38Před dnem
One good principle for solving Sudokus is “go where the numbers are.” In this case, the center block already has five cells filled in, so that’s a good place to start. An overall analysis of the puzzle indicates, as I say in the video (00:44), that the two empty cells in the bottom row of that block cannot be 1,7 or 3,5. However, since the block is missing the 1, 3, 5, and 7, logically there ar...
34. h54autres_4: Solving a Sudoku from the inside
zhlédnutí 41Před 14 dny
This is a beautifully constructed Sudoku by a designer and theorist called “champagne.” The solution unfolds perfectly logically within the inherent framework of the puzzle. You just need to recognize what that framework is. I will admit that I was spinning my wheels until I caught on to it, and then the numbers all fell into place using only simple tactics. I felt as if I had gotten inside the...
33. Pretty Beast: One night I had this dream …
zhlédnutí 41Před 14 dny
The solution to this Sudoku literally came to me in a dream. I was working away at it here and there over the course of a few days, but I was getting nowhere. I wasn’t even getting nowhere fast. It was hard slogging. But then one night I had a dream in which I could see the solution to the puzzle. (This isn’t the only kind of thing I dream about.) Unfortunately, when I woke up, I couldn’t remem...
32. First Peak: Sudokus are all about constraints … except when they’re not
zhlédnutí 37Před 21 dnem
With the exception of one important detail, First Peak is a Sudoku that exhibits the same pattern found in Platinum Blonde, Golden Nugget, and coly013 and in transposed form in several other puzzles for which there are videos on this channel. (See the comments on video #31.) In First Peak, the design is turned 90° to the right, but the “script” for the solution follows the same lines as in the ...
31. Transposition as a solving technique
zhlédnutí 84Před 28 dny
Something about our eyes and brains makes it easier for us to recognize information in some visual forms than in others. That was certainly my experience when I rearranged the Sudoku known as Trompe l’oeil. I found a much smoother and faster solution. So for very difficult Sudokus that could take many hours to solve, it may be worth it to see what insights transposition might make possible. In ...
30. Trompe l'oeil: The “givens” have much to tell you
zhlédnutí 35Před měsícem
As I looked over the "givens" for this Sudoku, I noticed a place where two of only three possible numbers (1, 2, 7) had to go in two cells that were in the same row and block. I then noticed that the other instances of those same three numbers elsewhere in the grid were positioned in such a way that the three possible combinations (12, 17, 27) could be efficiently tested by trying them by pairs...
29. Fata Morgana: Sudoku as an art form
zhlédnutí 27Před měsícem
A Fata Morgana is a mirage. But it is a certain kind of mirage. It is a reflection of an object in the air above that object. In some cases there will be a stack of reflections, alternating between right side up and upside down. I have to admit that learning the meaning of this term helped me solve this Sudoku. In most cases when a Sudoku has a name, the name doesn’t indicate anything about the...
28. Kolk: Pattern recognition can help inform strategy
zhlédnutí 39Před měsícem
Kolk is another of the ultra-difficult Sudokus I have been working on latey. I eventually recognized that it had the same basic design as cigarette (video #25). This definitely helped me work out a strategy to solve it. On the one hand, this means that Kolk was not as much of a challenge as it would have been if I had not previously seen cigarette. On the other hand, it shows that pattern recog...
27. coloin: You can always find new challenges in the world of Sudokus
zhlédnutí 22Před měsícem
It’s always possible to find new challenges in the world of Sudokus, and that's what this puzzle made possible. I explained in my comments on Imam bayildi (video #26) that I had stumbled onto a convention of the time when the ultra-difficult puzzles I have been exploring in recent videos were developed. (They all come from a thread in the Enjoy Sudoku forum, “Hardest Sudokus,” that was updated ...
26. Imam bayildi: A case study in tactics (even after a big hint)
zhlédnutí 33Před měsícem
The composer Sergei Rachmaninoff was also an accomplished pianist. He gave many concerts over the course of his lifetime. According to Wikipedia, he “always planned his performances carefully. He based his interpretations on the theory that each piece of music has a ‘culminating point.’ Regardless of where that point was or at which dynamic within that piece, the performer had to know how to ap...
cigarette: Longer, more detailed version of solution
zhlédnutí 20Před měsícem
This video provides more details of how I worked out the solution to the Sudoku known as cigarette. I trust you will agree with me that it is an amazing puzzle with unique and intriguing features that shine through even in the process of sorting out which of several paths leads forward to the solution.
25. cigarette: This must be a Sudoku from another planet
zhlédnutí 48Před měsícem
(Update to information on video: cigarette was created by a Sudoku designer and theorist who went by the name of eleven on player forums.) I saw things in the Sudoku known as cigarette that I’d never seen in a Sudoku before. To solve it, I had to use techniques that I'd never used before. All of this made me say to myself, “It's as if this Sudoku is from another planet!” In this video of the so...
24. Discrepancy: Numbers may be placed on strategic grounds as well as tactical grounds
zhlédnutí 54Před 2 měsíci
Chess players sometimes speak of “positional” moves. These moves do not have an immediate purpose such as attacking an opponent’s piece or getting one’s king out of check. Rather, they strengthen one’s overall position and create advantages and possibilities to exploit in the future. In other words, these positional moves are made on strategic grounds rather than on tactical ones. I’ve come to ...
23. Cheese: Identify the “active” numbers (and be prepared for surprises)
zhlédnutí 40Před 2 měsíci
23. Cheese: Identify the “active” numbers (and be prepared for surprises)
22. Patience: Sometimes the columns are the key.
zhlédnutí 37Před 2 měsíci
22. Patience: Sometimes the columns are the key.
21. Embrace the negative space (featuring the last 17-given Sudoku to be discovered)
zhlédnutí 50Před 2 měsíci
21. Embrace the negative space (featuring the last 17-given Sudoku to be discovered)
20. Look high and low, far and wide (largest empty region)
zhlédnutí 72Před 2 měsíci
20. Look high and low, far and wide (largest empty region)
19. A Sudoku with three empty rows, columns, and blocks
zhlédnutí 100Před 2 měsíci
19. A Sudoku with three empty rows, columns, and blocks
18. tarx0134: You may get a flash of insight
zhlédnutí 36Před 3 měsíci
18. tarx0134: You may get a flash of insight
17. coly013: Finding a key that unlocks a whole puzzle
zhlédnutí 75Před 3 měsíci
17. coly013: Finding a key that unlocks a whole puzzle
16. Red Dwarf: The power of proof-by-contradiction
zhlédnutí 97Před 3 měsíci
16. Red Dwarf: The power of proof-by-contradiction
15. Golden Nugget: Ultra-difficult Sudokus call for elaborate tactics
zhlédnutí 210Před 3 měsíci
15. Golden Nugget: Ultra-difficult Sudokus call for elaborate tactics
13. How “magic squares” work and how to find them (“Impossible #1” by David Eppstein)
zhlédnutí 76Před 4 měsíci
13. How “magic squares” work and how to find them (“Impossible #1” by David Eppstein)
14. Platinum Blonde: A Sudoku’s constraints shape its solution
zhlédnutí 141Před 4 měsíci
14. Platinum Blonde: A Sudoku’s constraints shape its solution
12.The better the Sudoku, the more paths to a solution
zhlédnutí 391Před 4 měsíci
12.The better the Sudoku, the more paths to a solution
11. Sometimes a Sudoku seems to tell you how it wants to be solved (Ruud collection)
zhlédnutí 86Před 6 měsíci
11. Sometimes a Sudoku seems to tell you how it wants to be solved (Ruud collection)
10. An "extreme" Sudoku with only 17 "givens"
zhlédnutí 1,6KPřed 7 měsíci
10. An "extreme" Sudoku with only 17 "givens"
9. Solving a Sudoku as nine interlocking number grids ('Unsolveable' #29 by Andrew Stuart)
zhlédnutí 2KPřed 7 měsíci
9. Solving a Sudoku as nine interlocking number grids ('Unsolveable' #29 by Andrew Stuart)
... I like To make Sudoku very much learned ThaT few years Ago
signed and sealed guys !!
There are 3 possible cells for entry of 7 in row 7 or column 6. Though your answer is correct, (column 2 row 7 or column 5 row 7?) It is not only getting the answer correct but also how you got it correct matters to lovers of sudoku 17. That was not explained.
As the comments on this video explain, in solving this Sudoku, I followed a particular strategy. It was to place numbers where they would generate the most further numbers of their own kind. As I say in the comments, "A 17-given puzzle is so sparse that the numbers have to come from somewhere. It is reasonable to expect that the puzzle may be 'programmed' to generate many numbers from a single one. So I would say that this is a technique that solvers should keep in their back pockets for situations such as this one in which it has logical, reasonable prospects of success." Admittedly this is different from the strategy of looking for definitive proof for the placement of each individual number. I certainly respect those who follow that strategy. But I also think that we can all find enjoyment and success with Sudokus in our own ways.
what the hell, how did you figure the 9 at 0:23 ??
That cell is in the same block where there is already a 1,2,3,7, and 8, and it is in the same row where there is already a 4,5, and 6. So it can only be a 9.
I still can't figure out why ypu put there 1 at start
You can think of the 1 as the start of a forcing chain.