Sudoku. Lesson 25 When all else fails. #2. The underlined pair.

#sudokuguy #sudoku

Take a puzzle where you are stuck, look for an underlined pair. If all other small numbers are correct you know that one of them will be correct. So if you try one of the two numbers and if it doesn't work then the other one will. This puzzle can be solved by using other techniques. I wanted to demonstrate another technique with this puzzle.

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May I say a big thank you for all of those fans out there from all over the world.

[irithelled]

You are a very nice guy and the best teacher I have had for many years, you teach in a fun and interesting and exciting way, my husband and I have learned so much from you, now I am not afraid anymore to approach Sudoku and I feel I can solve every Sudoku I'll see thanks to your technique, I'll deferentially will recommend your video to everyone I know! Thanks again :)

[ramchanderv]

Just wonderful ! Great teacher! Kept me absorbed all through and helped me be confident to solve the puzzles. Found the words at the end of each session so valuable . A big thank you!

[kamarinelson]

Thanks to these lessons, I was able to solve my first expert Sudoku. I sincerely thank you, you very awesome sir.

[dianefuhrman]

"We got trouble in river city" Hahaha! Seriously, you are a very good teacher!

[johnandkatie]

Thank you so much!! I went through all the lessons in two days. Now I will start over. I still need to get puzzles, but I've been wanting to learn Sodoku, and you're an awesome teacher. Thank you.

[leisuarez]

This video came at the right time. Thank you Sudoku Guy, I was finally able to solve a couple of puzzles that were very hard to solve and was stuck on.

[freysicht]

I look all the 25 lessons in TWO days. An i try it after every lesson! It was great!
THANK YOU für your step-by-step, for your funny words, your dekoration und the natural presentation! I enjoy the lessons very very much!!! (Sorry for my bad english!) Have a good time and stay allways Greetings from Germany. PS: The "swordfish" was very difficult for me, also the "skyscraper". But in this time i dont need it... :-)

[oumaroudia]

Let me start off by congratulating you (THE SUDOKU GUY) on a job well done. What I learned was short cuts that allowed me to shorten my Sudoku resolution time.

The course started with simple logical techniques to to solve Sudoku puzzles. But the introduction of the cleaver, mallet, table and diagonal cross patterns made things murky. The TMB and LCR are great and sufficient to tackle the cleaver, mallet, table and diagonal cross patterns I think.

The X-wing was well explained. That was not the case with the skyscraper and the swordfish. Yes perhaps one will need to spend more time on those more difficult concepts, slow down the videos and try to understand them. What I am saying is one can blindly apply the suggested techniques to solve Sudoku puzzles, but this becomes mechanical and takes the joy of solving because of lack of understanding.

Finally while lessons 24 and 25 were great opportunities to revise previous lessons, I do not particularly like the concept of “what if” in resolving Sudoku puzzles. It is tantamount to guessing and in my mind well constructed Sudoku puzzles should not allow GUESSING. Just my opinion. And it is the lazy route as demonstrated by David Han.

BUT ALL IN ALL KUDOS FOR A JOB WELL DONE. GREAT FOR ALL THE SUDOKU BEGINNERS AND THE MORE ADVANCED PLAYERS WHO WANT TO INCREASE THEIR SPEED AND EFFICIENCY!!!

[mjtullio]

Today I've finished the entire course and I have to say that I've enjoyed every single video, like a lot! I've been playing easy to medium puzzles with almost no difficult thanks to the first part of the course, now I'm trying the harder ones with help of all your advanced techniques, so far so good!
So, thank you Robin! I've never played sudoku before and now I'm enjoying it a lot!
I can't wait to watch more videos! Keep up the good work! =D

[milesong]

Thank you so much for the tutorial. You are a great teacher. I hope you were my math teacher way back in my high school or college years.

[sudokuoplossen]

As you already mentioned in other comments there are many ways to solve the puzzle from this point. I would ask the question "Where can you place the 4, 7 and 8 from block 9 in the 7th row?". With 4, 7 and 8 already present in column 3 and 4 you get a 478-triple in the 7th row.

[johnschatt]

The best teacher by far. I spent many dollars paying for another teacher. Don’t bother as this is very much better.

[Harphoney]

I learned finally how to play suduko because of your teachings. I can’t believe how much I enjoy doing it, in fact I’m quite hooked on it. I’ve been staying up at late at nite wanting to finish a puzzle lol. I’m so happy I finally understand how to do the puzzles. They are brain twisters lol

[vishwanathdatye]

Fantastic approach. I admire your way of discussing the problem. Thanks sir!!

[scatoutdebutter]

Sir, this technique could be called: "GUESS AND SEE WHAT HAPPENS"
You are an excellent teacher, sir, but this technique is less than satisfying.

[igormoral]

Thanks Sudoku Guy. Great tutorials You remind me of Actor Alan Ford

[dennisdonovan]

Thanks again Robyn ... I'm still learning and making plenty of "bone-heads". The "unwinding" you demonstrated in this lesson is my biggest frustration. In one puzzle, I got down to the last three squares only to realize that I had blown it! Ugh! I tried "unwinding" but it only seemed to make matters worse so ... I bagged it and moved on. 🙈

[caryg]

Looks like you can make a lot of eliminations on the 3's here. In box 9 (the bottom-right 3x3), the 3 has to be in row 7, and in box 6 (i.e. the 3x3 box above it), the 3 has to be in row 6. That'll allow you to cross out the 3's in all the other cells within those 2 rows. :)

[harrysurtees]

Robin, I hope you're having a fantastic day. It suddenly occurred to me, are the tricks like "X wing" and swordfish really just tricks to help solve puzzles faster, and if you fill in all the squares with the little numbers, any puzzle can be solved, without using shortcuts? I've been doing puzzles out of a book and was always getting stuck, until I followed your lead, and started filling in all the little numbers, and then figuring out which numbers can be eliminated, and walla, I've done the most difficult puzzles in the book. Before, I would always make a mistake, always. But now, I am more careful, go slow, and it seems like in the hard puzzles, you get to a point, there is only one move, and you have to hunt for it, but once you've found it, the puzzle gets easier and easier, as you fill in the squares? Am I wrong about that? Anyway, because of you, I have solved the hardest "CHALLENGER" puzzles in my book. I am grateful for your help, and will keep working your puzzles along with you. This is long, I know. Well, I took your advice, and printed out 7" X 7" blank puzzles on 8 1/2 X 11" blank paper and copy the puzzle onto my blanks and use different color ink for the little numbers, use Bic Wite-Out to erase little numbers, and it's working out great. Sorry this is so long, but I feel like I've done all the puzzles in my book, and now I have this one question? X Wings, and Swordfish are just tools to help solve puzzles faster?

[xoptics]

Great videos! I'd love to see a followup about 'finned' and 'sashimi' X-Wings/Swordfish. They keep tripping me up but occur quite often in harder puzzles.