Sudoku Demonstration - 2-String Kite Technique (Example 01)
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- čas přidán 27. 05. 2014
- As I've continued to grow in my ability to solve Sudoku puzzles, I've also continued to seek out more advanced puzzles to push and challenge myself to learn and understand techniques that are necessary in order to complete "Hard+" puzzles.
Keys to finding and using a 2-String Kite (in this example, we're filtering on the number "3"):
1. Look for one column and one row where only two possible candidates exist for a number (ie: Column Seven has two cells where a 3 is possible and Row Four has two cells where a 3 is possible).
2. Identify if the Row and Column intersect in a way that causes one cell from the Row and one cell from the Column to end up in the same "house" where the intersection of the Row and Column occurs.
3. Identify the "foundational" or "base" cells of the kite (the ones that ended up in the same "house" - these form the center frame of the kite) and identify the "relational cells" or "wing tips" of the kite.
4. Perform an "if this, then that" scenario analysis on the base cells: Notice what happens when you ask yourself "If THIS cell is a 3, then what happens to the other three cells that form the kite?", and then ask the same question while choosing the "other base cell".
5. You will notice that, in the first scenario, two cells will be "green" (possible) while the other two cells will be "red" (not possible) - and you will also notice that, in the second scenario, two cells again will be "green" while the other two cells will be "red" (noticing that "opposing cells" are either green or red in the two "if this, then that" scenarios).
6. Identify the "elimination cell" (the cell where the possibility of a 3 can be eliminated).
If anyone watching this video would like to see other examples of this particular technique, let me know and I'll post one or more videos demonstrating it. Or, if you have a question, feel free to send me a message on CZcams and I'd be happy to discuss it with you in more detail :).
If you'd like to keep growing in your Sudoku skills, but you're not quite ready for this level, keep practicing beginner to intermediate puzzles until you feel more comfortable and confident to take on new challenges like this and other techniques I'll be demonstrating in the months to come.
The application I used for this demonstration is "Hodoku"
hodoku.sourceforge.net
More info about the "2-String Kite" technique:
hodoku.sourceforge.net/en/tech... - Hry
Well done Huey, Once again the key is to spot the kite.
My unique and easy Sudoku solver, all is welcome 🙏
This is a good video but I found myself trying to drown out the music so that I could concentrate on what you were explaining. Very distracting. The focus is on your explanation of Sudoku so I suggest future videos just be you and Sudoku and no music. Thanks
I totally agree - a lot of people didn't like the music, and I can see how distracting it was. Thanks for the feedback - I haven't used music since, and I'd really like to get back into making more videos (music-free of course ;) ). Hopefully I'll have some more instructional videos up in the months to come! :)
This technique is great. I'm a big fan of the "either/or" types of strategies; thanks for the demo and the clear explanation.
I was able to understand perfectly. Thank you for your help.
My unique and easy Sudoku solver, all is welcome 🙏
Well done Huey. You explain it well. Now the problem is to spot it.
Great technique. I'd enjoy your video more if that music wasn't playing in the background.
I like the way you explain advanced techniques, please do more on this channel, thank you.
Thank you Juan! I really do want to make more videos, but have been struggling to find the time :(. I hope to get more videos up soon though!
@@Shuey187 Thanks, I like the tone of your voice and your detailed explanations, I'm now looking for 2 string kites in my Sudoku puzzles but I could use more examples.
Thank you sir
All is welcome too🙏
In response to Mark's question (his comment was "linked" and there is no reply button): The cells at r4c3 and r7c7 are the two relational cells you mentioned that can "see" the 3 in r7c3, thus eliminating it as a possibility.
Very good tutorial. Thank you!
Thank you for the feedback - I'm glad it was helpful! :)
omg .. thanks so much, I've been trying to finish a puzzle for ages, and wouldn't give in, I've researched x-wing, y wing, swordfish, skyscraper and finally after watching this, I've managed to resolve it... I've looked everywhere :)thanks for your help!
You're the best at explaining these advanced techniques. I recommend trying to include an explanation on things that might trip up people when doing these advanced techniques, to clear up confusion. Like for me, I kept looking at the 3 candidate on r6c9 wondering if that could be removed as a candidate since you were showing how there has to be a 3 on r4c9 or r6c7 until I realized to ignore the 3 on r6c9 since that has nothing to do with the kite technique.
Thanks for the advice, and support! I'll definitely try to incorporate that idea into my upcoming videos! :)
Shuey, did you pick out the 3 to eliminate in R7C3 because it is where the relational cells intersect?
When I play Sudoku I usually first go with the basic techniques, finding only possibilities etc. Then I start searching for more advanced things if necessary, look for twins, triplets, x-wings, xy-wings, swordfish, whatever. If I do a harder puzzle there is always a point when nothing helps anymore. Basically what are left unsolved are a couple of twins and triplets that are no longer useful for elimination, and a bunch of numbers that I have a hard time ruling out because many of that particular number has to be found yet. My last resort is after desperately searching for quite long I just have to realize that nothing works, and I need to take a guess at one of the squares(usually I take one where only 2 candidates exist) and see if it provokes any collision. It's frustrating and time consuming, I've been searching for tecniques thinking maybe I'm missing something important but no, every guide says that the techniques I use should be able to suffice for 95% of the puzzles, well aparently, most online sudokus hardest puzzles don't fit into the 95%.
I understand where you're coming from, but any valid puzzle can be solved without having to "guess" and follow the chain. On rare occasions, brute force is the only method, but again, this is extremely rare. If you enjoy difficult sudoku puzles, I would recommend installing Hodoku and using that to help you figure out the areas where you get stuck. It's a great learning tool.
Well I found a website with an engine that is able to solve puzzles. Where I'm stuck, instead of guessing, it uses 8+ long XY-chains, no way I'm going to keep that in my head, it's faster if I just guess. It'd be cool if I shouldn't have to, but for an XY chain that long to keep in my head and spot a single number that can be excluded from 1 or 2 squares, it's almost harder than to calculate a long tactical chess variation.
the another three in the 3*3 box can be excluded
thank you..
but please explain with more examples like you did for skyscraper
I have been trying to understand the 2 string kite..but having difficulty..Can you post more examples solving the 2 string kite? I appreciate that you posted several on the skyscraper technique.
+Barbara Ratliff Thanks Barbara :). I have had plans of uploading more videos for the last couple years but I've continued to fall short on that commitment because of how busy I've been :(. I'll see what I can do when I get to a point where I can start rolling out videos again ;).
Barbara Ratliff Learn abut Colouring and multicolouring tecnique, I think from my point of view, 2-String Kite is just a particular case of Multi-Coloring whish is very powerful
hey, I was wondering, you see the cell in the 6th house at the bottom right corner, couldn't you eliminate the 3 in that cell too? because of the "if-it-is-or-not" situation
Technically, "yes". But you wouldn't use this technique exclusively to rule out a 3 in that cell. Hope that didn't convolute things even more, lol.
Well done. You are brilliant to explaine. What kind of Sudoku program are you using ?
Thank you! :) The program I use is called Hodoku (hodoku.sourceforge.net)
helped me solve an *Annoying* so thanks! :)
what kind of program or app do you use to solve sudoku's?can I download or buy this?
I use a free app for Windows - it's called "Hodoku" (hodoku.sourceforge.net/en/index.php)
What happens if R6C9 is a 3? Is the technique still useful?
Many people get distracted by the 3 in r6c9, but that's all it is at this point in the puzzle; a distraction. There's no technique available at this specific point in the puzzle that would determine with certainty whether the r6c9 is a 3 or not. It's best to go with the available option and worry about the 3 in r6c9 when a later option will rule it in or out.
This is so helpful. Thank - you for posting. Please post more tutorials!! :)
PS - I wish you would lower the volume on the music or delete it completely.
+Wendy Helena Thanks Wendy, and thanks for the feedback on the music too. I've gotten the same feedback from others as well. I agree, I definitely need to drop the music volume way lower or just completely remove it. I'll try to get more advanced tutorials out later this year :).
Welcome to our sudoku solver solution
What if the 3 in that box were in R6C8. Does it matter that there are other possibilities for a 3 in the box you are working on? Or is that not an issue?
Thanks for the question Peter. If the 3 was in r6c8, the only way it would've worked would be if the column that the 3 was in only had one other 3 (if the one existed in r7c8 for instance). And the other possible 3 in that house (r6c9) is one we don't have to pay attention to since the kite is definitely spotted and can be leveraged.
I hope that info helps :). If you still need help or want to ask some more questions and discuss the technique, don't hesitate. I'm actually really happy to see people asking questions because the ultimate goal of my videos is to help people grow in their understanding and ability to solve difficult Sudoku puzzles ;).
***** I appreciate the feedback and comments. I hope this info will help: You are correct about the conjugate pairs if you are considering these pairs in relation to an intersecting column and row (where TWO of the cells are shared by the intersecting column and row). The link you referred to still exists in a single box. The fact that another 3 appears as a possibility in that "house" is irrelevant because it has nothing to do with the fact that the intersecting row and column ONLY have two possible candidates that help form the link. I apologize if this is confusing. I'd be happy to discuss it further though - please let me know :).
Shuey187
whats the background music please
It's "puzzlement" by "bugseed" ;)
I have never benefitted from this maneuver, every-time i see the opportunity to put it to use, the square it directs me to, to possibly make a deletion it is always already occupied by that number.
Thanks for posting these helpful videos! Skyscraper has helped me solve difficult puzzles where I 'd been stuck & hit dead ends. Miskity also had great ideas that worked. My thorn is "swordfish" , I don't "get it" no matter how many times I've tried to learn it using websites like sudoku snake.
If you're familiar with swordfish or jellyfish , can you possibly post video or offer any explanations on how to spot a fish? I 'd be grateful for help mastering these.
Thanks M H :). I've been making promises to people that I really need to follow through on. I'll do my best to get some swordfish and other fish videos up as soon as I can! :)
Shuey187
That would be great. Need all the help I can get ! I stumbled upon technique I've been playing around with that actually can tell me in which cell a candidate actually belongs. Have not seen/ heard of anyone using it .
Took weeks & many hours (I'm retired) It involves using sets of conjugate pairs. Only four rows and four columns each must only contain two cells of a candidate. For ex. Rows 1, 3, 4, and 9 each show a pair of 5's, and
columns 4,5,7, and 8 only have the paired 5's- then look across those rows 1,3,4,9 to find any cells that intersect (share) with any of the columns 4,5,7,8. ( I scribble a circle or mark in these boxes to remind me where they are until I have finished.)
Now check & determine if this CELL can "see" or share any other marked intersects, If it doesn't it's a free spirit & the WINNER and can now be placed in that cell. Sometimes there won't be any singles revealed so just search for a new candidate that may have the same scenario lined up. Hope it isn't confusing lol (Prob is)
Maybe I better make a vid too for all the sudoku addicts }8>D
M H Miller
The technique you describe is actually a type of fish (IIRC). I'll make a note of your example and hopefully add this to my list of techniques to demonstrate in the future (with the associated method name) :).
Are columns 2 and 7 considered to be a skyscraper?
Earthbound Cory Hey Cory, sorry for the delayed reply! I'm not sure which cells you're thinking of, but I don't see any cells in columns 2 and 7 that would qualify for a skyscraper :-/
Shuey187
Love your vids, you're a great teacher. Could you maybe lose the music. I have trouble concentrating on what you are saying. (I'm a musician so there is no such thiing as background music) THANKS!
Thank you so much for the feedback, and I totally agree with you; I need to skip using background music on all future videos. All of my future vids will be speaking only and will be much easier to follow along with in terms of no extra noise to distract the viewer. Thanks again for the support and honest feedback! :)
You fail to mention that you can find what looks exactly like a two string kite but does not have a candidate to erase, that is if I understand this correctl. So when looking for a two string kite you did not mention to also look for a the elimination possibility. This is what happens when someone understands something so well they think others must automatically know it. Those who know do, those who don't teach.
Hi Dave, I apologize if my example was not fully understood. I do my best to teach foundational Sudoku principles, but I realize that some of the advanced techniques I teach about will go well beyond the beginner level, so it's impossible to please everyone with my instructional methods. I hope that you'll continue to grow in your abilities and that my videos will eventually be helpful.
yeah lol it's time to commit sudoku
No offense, but the repetitive background music is a distraction , annoying. Thanks for sharing though. Good pointers
Thanks "Fred" :D. Mark posted the same type of comment about 5 days ago and I agree. It was a mistake I didn't even realize at the time that I recorded it, but I was learning and didn't know any better. I'll definitely be making more videos eventually and won't have distracting music in them ;).
Too much empty talking and no actual useful info
verox43 Thanks for the feedback verox. What would you like to see/hear? Is there anything in particular you think I could've done to make this video better?
Shuey187 While the video could have been boiled down and shortened -sort of cut out all the fat - the tip actually was very usefull. I have a few sudokus I am stuck with so I went into CZcams for some tips and tricks and ended up here. This algoritm was new to me and usefull, and the above comment was rude and not necessary.
Filip Wessman Thank you Filip, I appreciate the honest feedback AND encouragement :).
Shuey187 Keep it comming.