The Sudoku Trick All Expert Solvers Know

He's driving me crazy with that missing 6 in the upper left-hand box. I want to holler at him "PUT THE SIX IN THE UPPER LEFT BOX!"

Impressing!

The logic of sudoku is so elegant 🥰

I always fill in pencil marks for all unknow's before I begin. Its easy to do if you're using a digital puzzle. Once you see all the possibilities it makes it much easier to see the singles and patterns. You still get stuck, but it allows you to solve puzzles much quicker. Sometimes I use the Set Checkpoint method, as well. When you're certain of two numbers in two remaining cells within a larger cell or row/column you can set the checkpoint and try one option. Its 50/50, if one doesn't work, reset the checkpoint and try the other. I can solve some Very Hard puzzles in 12 to 15 minutes using the above methods.

I play nyt sudoku and that one was easy

I solved sudoku for years, but this one I didn't know (since I didn't used pencil marks). Thanks a lot. I think this was the missing link for solving the hardest sudokus. But now at the end I have to use this f*cking pencil marks 🙂

It's logical to put the obvious numbers in first, then put the small pairs of numbers in.

I was seeing that trend, but couldn't quite grasp it.. Thank you!!

Pencil marks are "cheating," no need to use them if you know how to solve the puzzle properly.

What app are you using? It’s much better than the one I have

I've been playing Sudoku quite a bit over the years, but I always played it on Easy or Medium, on "Sudoku - The Clean One" App. I binge watched a bunch of your videos recently and I just never even used the pencil mark feature. I straight up did things in a weird way that got me the result anyway, works on easy sudokus pretty well, but would never work on Hard or Extreme. Since using pencil marks, I can do things much quicker on those modes. I got this one in 28 minutes though... I think my biggest mental issue was, and perhaps I am spoiled by the app I use, that your website doesn't remove pencil marks when I place a number... but that probably only saves a tiny bit of time... I pencil mark every box numbers could go in and then use logic... so baby steps.

One cannot help but think that there must be a cleverer way of solving these puzzles.

Hmmm. Rewrite on paper. Solution took 5 minutes.

How can you have 3 sixes in the diagonal? They should be 1 to 9 only.

I thought everybody did that or something similar but why limit to 2 possibilities. Include rows or lines with 3 possibilities helps it unfold quicker. I would also have completed doing all the numbers with 2 possibilities. Eg 7s in row 6 columns 1 + 3.
I also do not actually pencil in the number, I place a small dot in the appropriate place in the square. Eg. 1= upper left [as your puzzle shows in row2 column1], 2= upper centre, 3= upper right,.....9= lower right. A small cross on a dot indicates that number is no longer viable. Works for me!

Thank you for the sharing

In my opinion using pencil markers feels like cheating. I feel like it's just more fun and challenging without the pencil and even though it would take slightly longer as you'd have to remember the potential numbers, it's even more rewarding once completed.

that is really helpful

I solve my puzzles in ink. 💪

Wrote a program that fills in all the possibilities for each box. Boxes with one possibility are filled with that number and the rest of the boxes in a square and row have that number deleted. However, on all "tough" puzzles the end always comes down to a final guess where several boxes have pairs of answers which either completes the puzzle or does not. There is no further logic that will give a solution.

Either/or logic is how I start all my sudoku puzzles.

❤ tic tac toe...how to cancel out three sixes ( 666).. in a row...❤❤❤❤❤😂😂😂😂🎉🎉🎉😢😢😢😮😮😮🎉🎉🎉🎉😂😂😂😂😂😂😂❤❤❤❤❤❤❤❤❤❤❤❤...effective time binding...virginity is the key to time travel....

Wow

This is the way I do it.

I never put possible numbers on the box(es). The presentation was good.👍🏼

Perfect! Thank you. It makes such a wonderful change to have someone speak clearly and intelligently (sorry, but I'm a Brit and I appreciate both the tempo and the accent...) and, of course, the overpowering logic laid out so clearly. As good as a good movie - oh, and I'm a techie, too!

I d suggested not to write anything in the boxes. Only 2 littles dots to point pairs or triple. The rest stays in your brain. The grid will stay clean. Then only use writing in corners when you are obliged to work on a hypothesis

Satisfaing to see those techniques which I developed by the time of solving Sudoku's on my own. That only proofs these riddles are all about algorithms.

Not at all how I did it, but it's interesting to see the thought process of someone else.

Me seeing the video: Ah, interesting. Will take a look at the trick but prob not watch the whole thing

Over 17min later

Me: Wait, I watched it all

Nice tricks. Really would simplify my brute force pencil marks as I'd normally put every possible allowable number in each square from the get go then filter them after

Looking like Sean Locks younger brother

I am so disappointed! I thought this video would teach me a new, "magical" trick. But there was nothing in it I didn't figure out by myself years ago.

Really like your videos but I can't stop thinking you are the sorting hat from Harry Potter.

I do it with adding the little numbers.

Is it better to be faster? Not necessarily because it’s easier to trip up. Logic dictates the speed. But what slows me down is wondering if I left the oven on etc. This was great at showing the patterns hidden within the puzzle.

Do you control the Sudoku app? Would it be possible to add highlighting, where you could e.g. click on "1" and have all "1"s highlighted? This gives you very good and quick visibility of open spots and is a major help in solving quickly...

Too easy. Didn't even use a pencil. I might watch your video later.

Hmm. Wondering why you didn’t start by completing row 4 and building upon that. Row 4 can be solved with 100% certainty.

I wrote a computer program to solve any sudoku puzzle, and now I can solve them in a second or so. I wrote the program, so it's my solution. It's just another technique. Is it cheating?

I'm definitely going to be carrying these over to my sodoku solvings :) love the paired cell idea for clean penciling cells

Late to the party, but thanks for this video. 
I've been solving 4x4x4 Sudoku puzzles for several years. Do you have any tips like this which can be helpful in speeding up the solving process? I've been relying mostly upon memory rather than upon writing possible numbers into squares. It's often surprising how many digits can be remembered when there are 256 squares with up to 16 numbers to think about in each square if the puzzle. 
Sometimes, however, a grid of potential numbers can occur which don't have an immediately obvious solution, apart from guessing and seeing what happens. How can we overcome that situation?

First time I’ve understood what x-wing meant on sudoku pages!

Thanks! Great voice for it too

A complex way, but it seems to work. I