A Sudoku With A Single Given Digit - Still Possible?

[@OsvaldoChannel1]

I have no idea as to why the algorithm suggested this channel to me but this stuff is hypnotic, thank you algorithm

[@at8ax]

It always strikes me as odd that you use green for "no" (aka "stop") and red for "yes" (aka "go"). Remind me never to ride in your car.

[@TheAgentAPM]

Well, this is how you go through watermelon. Perhaps he likes them.

[@jdyerjdyer]

Maybe because it is "Sandwich Sudoku" green stands for mold and you don't want mold on your bread...

[@nathanfievet5546]

I do think it is because of visibility. When the sudoku is all red you cannot read the numbers easily.

[@jdyerjdyer]

@@nathanfievet5546 I used black myself to just mark off the ones that couldn't be 1 or 9, then after all those were placed I selected the entire puzzle and cleared the colors.

[@devonhalford5522]

Josh Dyer does red mean that your sandwich is good to eat cause personally I wouldn’t eat a sandwich that was entirely red

[@payaniga-prashanth]

First time ever I heard about 'Sandwich Sudoku'! Watched till 5:00, paused and took me 32 mins to solve it completely :)

[@Jackjesse-jt5ii]

When you see a move but you can’t do anything about it AHHHHHHHHHHHHHHHHH

[@OsvaldoChannel1]

Yeah, but while you are screaming "THAT NUMBER GOES THERE" he finds like 5 more elsewhere, so there's that

[@yrrahyrrah]

Well, you could just click on the link below the video and solve it yourself ;)

[@snowfloofcathug]

harrythedevil Silly Devil, I miss too many things in between Simon’s misses!

[@TheWalkerboh65]

One of the best Sandwich Sudoku's I've ever done. Its one of the few I've done that uses all the clue both in the placement of the 1's and 9's and all sums are needed to solve the rest of the puzzle.

[@snowfloofcathug]

walker_boh_65 Well done!

[@guilhermemarra3099]

beaten the puzzle in 26:33. Not the hardest i've seen, compared to some on the app. Some took me well over 40 minutes to finish I'd love to see a "check" feature in the app. I don't like to use the "All Errors" option, as sometimes I just misclick and instead of putting it as "pencilmark" I put the number in a cell, and immediately knows if it's wrong or right. But I turn it on sometimes to see if I've made any mistakes along the way. The problem is that opening the options in the game makes you lose all your "redo", so if I've made a mistake and then turn on the "All Errors" function, sometimes I have to start over. Having a "check" option would make it so that I could check that all my logic was correct (or wasn't) and make me able to retrace the steps to find out where I screwed up. There's some space for some buttons above the grid. Maybe you could make two different "checks". One for "checking with the answer" and one for "checking if I haven't placed two of the same numbers in a row/box/collumn". This last one would be pretty useless IMO, but maybe it'll be of some use for someone Edit: This whole comment is based on my experience with the iOS version of the app. I don't know if it's exactly the same for android or steam

[@Herculean.Aficionado]

Never had sudoku explained ot me so i never understood the rules. I do now and i have a decent understanding of how to solve it quickly. Great commentary

[@gposchman]

Love sandwich sudoku, I bought the app for PC, and I'm looking forward to the next 5 games. I'm a Patreon, and I highly recommend it. It is inexpensive and if you like Sudoku puzzles, Mark and Simon are great. Good solvers and great educators and fun to watch. Watching them do live solves is great fun and educational.

[@abdoroma6928]

You hacked everything

[@Pyromonkey83]

Been itching for more of these! I didn't realize the app was updated last night, so I'm super excited to add more stars to that 189 tally! I'm very excited to see the challenging ones. :D This was a great one as well, took me about 15 minutes from start to finish thanks to all the practice I've had. ;)

[@shane8037]

Oh man, I was pumped when I saw that update because I just cleared number 40 😎👌

[@caitygart]

Really fun one. I'm a total novice at Sudoku but I really enjoy your content and feel like I'm learning more each time I tune in. Thanks for another great video!

[@adrianhead6272]

YES!!! First sandwich sudoku attempt without first checking the video... and I completed it successfully in 23m12s (comparable with the video) - very happy!

[@CrimFerret]

I seriously wish you'd create a general app for standard Sodoku with that UI for mobile devices. As near as I can find, there are no others that offer the corner and center markings as choices for where to put the marks. That's an app I'd pay for with no hesitation.

[@garanceadrosehn9691]

Here's a thought on the user-interface of background colors: If you have one or more squares selected, then you cannot tell what background "note" color (if any) those squares have. One way to avoid that would be that if a selected cell has a background color, then leave that background color as a smaller square in the center of the square, and use the selected-cell color as a frame around that background color.

[@garanceadrosehn9691]

I do have the app, which I'm playing on an iPad. One mistake I'll make is that I'll have the app in the "normal" mode (the square which has a single '1' digit). I'll then select multiple squares, and type in a set of digits for those squares. Since I have multiple squares selected, the app knows I can't possibly want "normal" mode, so instead it puts the digits in the corners. My mistake is that I'll then think "except that the second square can't have a '7' in it), so I'll select that single square and tap the '7' to erase it from the list of digits. Except that now I have a single square selected while in normal mode, so instead of erasing the '7' it erases all the *other* digits and then puts in the '7' as my choice for that square. I'm playing with the option that immediately shows me if I've made the wrong final-choice for a square so I notice the mistake immediately, but every time I do this I get irritated with myself, and lose a little time on the game-clock while I fix the mistake. So I'm wondering if it would be friendlier that if I'm entering digits while multiple squares are selected, then the app would switch modes from "normal" into "corners" mode. That way I can safely select a single square to erase one of the digits I just entered. It's also quite possible that I'll just get myself trained to not make this mistake in the first place, but I thought I'd suggest that change.

[@garanceadrosehn9691]

I find that I do enjoy the sandwich sudokus a little more than a standard sudoku. I'm solving one a day. The first day it took me about 80 minutes to solve it, but the last two took me a little over 40 minutes each.

[@garanceadrosehn9691]

Also, on the hints: I often had to resort to hints for the first 15-20 sudokus that I did. I don't know how hard this would be to implement in the app, but it would be nice if it did not show me any hints for squares that I've already filled in. When reading the hint I have to keep switching between the game screen and the pop-up screen which has the hint in it. On some hints I have to do that a few times before I'm sure I understand the hint, and then I see that I already have those squares filled in so that hint wasn't of any help to me. And all the time I'm doing that, the game clock is ticking away!

[@NickCarney94]

@@garanceadrosehn9691 You can change the setting for "Number entry with noted cell" to achieve this. By default it will fill the cell but you can make it so it will remove the note instead.

[@garanceadrosehn9691]

@@NickCarney94 Hmm. I'll try that for awhile and see how well it works for me. Thanks!

[@henryordish]

video starts at 3:05

[@tadperry1817]

Fun puzzle! I like the sandwich sudoku's because although the logic can be more complicated, the sandwich totals are an extra sanity check that I'm not making a mistake and if I do make one, it can be a lot easier to unravel what went wrong. I love games and puzzles. To me, life is about collecting talents and I want to collect the "Good at Sudoku" achievement.

[@stuartmcconnachie]

4:30 33 + 1 + 9 = 42 ? I know it’s the answer to life the universe and everything, but not in this case!

[@li_ka2]

Yes, that's why the 1 and 9 aren't both at the edge, there could for example be a 3 outside the 1 and 9.

[@stuartmcconnachie]

li_ka2 I think you need to check your maths.

[@li_ka2]

@@stuartmcconnachie yeah, I realized my mistake, and that you were making a joke, my bad.

[@noahkupinsky1418]

I’m guessing he was thinking about the fact that there could only be a 2 outside the 1 and 9 and accidentally said 42

[@hdhdhd9375]

@Indie Arts sut up you can't evin spel

[@lennartmuijres664]

Nice entrance through the exclusion of box 6. Took me 13:52. Love sandwich sudokus, I'll check out the app!

[@facilvenir]

It took me a lot of restarts and 33 extra minutes, but I solved it! Great puzzle. Now, I get to see how you solved it. Thanks!

[@Ten_Thousand_Locusts]

The first part of the puzzle kind of reminds me of a nonogram.

[@michaelxfade]

Thanks to your app, I am getting much better with these. This one took me 13 minutes.

[@williampowalski4222]

love the ending. both ways are valid sudoku solutions but only one is a valid sandwich sudoku solution.

[@kamil6438]

I love these sandwich sudokus! And I love your app too, it's great! Made this one in 44 minutes. Not so bad, I think.

[@stuffedlegoguy461]

25:14 for me! Finally feeling like I'm getting the hang of sandwich sudokus

[@davidgeier6365]

I was screaming THERES A TWO THERE!!!! In my head then you put one there and I got so happy. :D I have yet to solve a normal sudoku XD

[@eskimoprime09]

I haven't seen him start the puzzle yet and see his strategy, but just by looking at it I can tell it'll be very similar to griddlers.

[@chrisj50]

Very enjoyable - took me 30 minutes. Thanks for all the puzzles!

[@joshuangerng2119]

Now given digits are so rare, that Simon officially zoned out black digits hahaha

[@yeetdatcodeboi]

who else got ptsd from him not placing the 9 in row 5 till 12 friggin minutes?

[@roybatterham5002]

Yes, it was really freaking me out and then the 68 directly under it

[@Czeckie]

i've just finished the 35th puzzle in the app. I have to say, that 34 and 35 were the first really difficult. I've done 34 without help, but 35 was my first use of hints which I am slightly ashamed about. But I learned something and I hope it will be smooth sailing from now on. Thanks for the app.

[@TJSq]

Lol wow you really needed hints on 35?

[@MrCharlieArgo]

I loved this puzzle! I solved it with no hints (after one false start due to a bit of faulty logic, whoops). I looked at the timer when it finished to see a time of 50:51! Wowowow, that time really flew by. Are we positive that the timer is accurate, though? Maybe it runs fast? haha, jk, trying to make myself look better. Thanks for the great puzzle.

[@johnkneelad]

Brilliant! I enjoyed that.

[@dkalambokis78]

I struggled so much with this, maybe that's why I'm so proud / relieved with my 53:15!

[@corbosman]

Took me a bit, but finally finished. Very nice puzzle.

[@cgomes12]

I am loving the app. Very well done!

[@vlahovivan]

27:47, very cool

[@super_7710]

Woop! Solved it in 56:08!

[@JuanMataCFC]

took me 40mins to do this one. i think this is one of the harder ones i've done, but i def enjoyed it!

[@dreamlover3459]

never done a sandwich sudoku but this video still messed up my brain. I will stil to normal sudoku, its the only one I know how to do lol.

[@intercat4907]

This was a very pleasant 23 minutes; thank you.

[@kasraew]

took my 68 minutes to solve it but I'm still proud of myself. great fast solve here!!

[@RhejMacTavish]

Never seen one before; paused and got it solved in 45 minutes; definitely leaning on previous Killer Sudoku solves for getting the numbers that fit in the sandwiches. Interesting concept!

[@Coyotek4]

14:26 The more I do these, the better I get. Guess I shouldn't be that surprised, though.

[@23Magistere]

Hi, very nice video ! What's the difference between putting numbers in the corner and putting them in the center ?

[@danielbriggs991]

Took me a little under an hour and a half. But I haven't done many Sudoku puzzles ever, and I hadn't done one in a long time.

[@shane8037]

Shout out to all the real ones who been playing the app and did this one in their head with no calculator for the first time.

[@glennmelven3414]

I only like to check the possible sums when I get stuck. Sometimes seeing those numbers listed will give me a hint to what I can put in there.

[@RoderickEtheria]

Solved in 23:10

[@schocker655]

Nice puzzle took me almost 2 hours to solve, but I am actually happy that i managed to solve it without guessing or trying random stuff. Also well done on this solve ^^

[@Brimstone-Gaming]

what is the website for the puzzles.

[@sean00141]

"unfortunately that's not resolvable yet... EXCEPT THAT IT IS"

[@57thorns]

The situation at 12:50 where the position of the 9 on row 4 is determined by previously place 1/9 is interesting. It is not necessary in this puzzle to use to to place the 9 in row 4, you can go on placing the other 1/9 pairs without resolving them until you have the whole puzzle solved. But I wonder if it is possible to create a puzzle where you have to start resolving 1/9 partially to determine where the last 1/9 square are?

[@glennmelven3414]

At least one 1 or 9 has to be given. This is not given to determine where the 19s are, but to differentiate between them. Without that given number all 19s would be interchangeable and the puzzle would not be unique. See Simon's video on Mozart's Sandwich sudoku. His death year is the only way they can be differentiated. The 19s are not part of the sums that are outside the grid. The only way you could do what you are asking would be to make the 19s part of the sums.

[@57thorns]

@@glennmelven3414 Not necessarily. Look at the situation again: If this had been a minefield variant (just stating that two mines in each row and column) there would be no way to differentiate between the possible placements of the mine in row 4 at this point. However, if you keep solving the green square (numbers 2-8) you will eventually see which one it is without assigning identities to the mines,. So my challenge to puzzle creators is this: Make a sandwich sudoku where you cannot determine where all the 1/9 pairs are without resolving from a given 1 or 9 and then go on to solve the rest of the unique sudoku. The given 1 or 9 would still be needed to resolve which one is 1 and which is 9 of course, but it would also be necessary to resolve which of a number of candidates are a 1 or a 9. One way to do this would be to crate a uniqueness issue, a series of 1/9 pair not connected to the given digit, forcing the solver to abandon one of the 1/9 pairs for another that is connected to the given digit.

[@generalhotdog33]

#45 on the app hurt my brain. Diabolical sandwich!

[@saaampe7229]

lovely puzzle, took me about 35 mins

[@charlesmangum3108]

Of course you can. You are producing your own matrix, which will be one of many solutions.

[@aBanabis]

easy puzzle. it took me negative 26 and a half hours and i gained a day to my life span thanks to this. git good.

[@CoenBijpost]

So, in when do you use the corner and when the center notation? Corner for pairs, center for multiples?

[@kieranmoynihan1161]

Coen Bijpost He uses corner notation in relation to Boxes. If a 7 is in the corner of 2 cells in a box, the 7 must be in one of those 2 cells. Center notation is used (by Simon) to identify which values a cell’s true value must he a subset of. If a cell had 68 in it’s center, the true value must be either 6 or 8.

[@LazyMonkey24]

Solid 3 1/9s correct before I screwed up my logic, I’m not good at these

[@jdyerjdyer]

I'm still surprised, though I shouldn't be really, that even a puzzle like this one that seemed pretty linear for figuring out the 1 and 9 placement has multiple paths to solve. You started out the same, but quickly diverged and solved everything else almost opposite to the order I used. Very intriguing, indeed.

[@dave-in-nj9393]

how many are screaming a 9 goes in row5 column1 ?

[@glennmelven3414]

I didn't find this puzzle to difficult. Finished in 21:25. I think that is about the closest I have ever come to beating Simon's time. Simon not resolving that 11 in R5 I found quite annoying as it resolved othe 19s instead of making them either/or. That 9 in R5 was my first digit.

[@Pwecko]

One hour and 47 minutes. I got all the 1s and 9s and then messed up somehow. But I came back to it and got it right. Eventually.

[@rigdigwus]

it really bothers me how you didn’t finish row 5 with the 9 was earlier

[@jvcm8649]

21:32 woah beat the videos time haha

[@dimitrisvasilaras4866]

Ah yes, its all coming together

[@michaelbard420]

How do I highlight non subsequent cells? The controls say hold ctrl while clicking cells but that’s not working for me or I’m doing something wrong. Any pointers?

[@tadperry1817]

Hold control down while moving the pointer and clicking separately on each cell you want to mark. Should work. It's not totally intuitive if you're not used to it.

[@Anarchapal]

1h13m47s for me My first sandwich sudoku, it was really hard, and I'm really suprised that I succeed but damn, that's good !

[@Jubbinn_]

Big brain

[@PuffyOne1898]

49:07 with very little help from this video!

[@tiemen596]

26:21, while eating. Not bad :D

[@Sianistic]

Did it in 29.28 :)

[@The123Christian]

I felt like puzzle #45 in your app was much easier than #44. #44 took me over 1 hour and #45 like 25 minutes

[@DaveGeelen88]

you cheated ??

[@videakias3000]

weird,i did everything right except for one number 7 and the websites thinks i did everything right

[@PotPoet]

Wow.

[@prosperhuang]

Isn't it easier with just 1 number because it gives you so many possibilities

[@slomopanic]

Yes normally it would be really easy. But seems he has extra rules applying which makes it harder. With the extra numbers outside the grid.

[@ShiriAtsmon]

1 hr 13 mins 13 secs from me. Not to bad on my standard

[@rwj_dk]

Squares where something can’t there = Green color... Would be easier to understand if you used red color

[@57thorns]

Just what you are used to. Green to me feels like the less restricted of the restricted squares, while red is either 1 or 9, blocking all others.

[@carolaqalk5978]

14 minutes to finish. It would be fun if you had harder sandwich-puzzle than this one. You solve sudokus that are insane but the sandwich, so far, have been quite easy (except for 1 puzzle)

[@Pyromonkey83]

Totally understand if you don't have the $5 to purchase the app, but if you are looking for challenging sandwich sudoku's, their app has them in spades. The first ~25 or so puzzles range from easy to medium, but the last 10 definitely dial up the difficulty significantly, with the last 5 puzzles probably taking me as long as the first 20 combined. It's well worth a purchase if you want quality hand made sudoku's.

[@dekrachtbron-be]

Try the sandwich sudokus on www.tectonicpuzzel.eu

[@carolaqalk5978]

@@Pyromonkey83 I am sure that they have good ones on their app, but I was talking about the ones they show on this channel. Compared to the sudokus they are very easy. There have been only 2 really good (=hard) sandwiches (that I have seen). One called "Liar" and one called "Mozart". When it comes to sudokus there have been thousands that are extremely tough.

[@cuneytsonmez]

I'm 46 and sill trying to be good on classical sudoku. This looks far beyond me. Maybe in next life.

[@ThePcroz]

Not sure if it's just me, but app is broken since update and doesn't display congratulations screen when puzzle completed (Android)

[@samcappleman-lynes6914]

Works for me - you might want to make sure you've actually got it right! You won't see the congratulations screen if you've made a mistake ;)

[@mateuszzemojdzin7579]

13:09

[@Hochmoa]

Took me 2 hours, idk if I can be proud of it

[@Jolly0872]

solved in 49:44 :)

[@kimberley03butterfly]

Ooof, 45 minutes as I went wrong twice 🤦🏼‍♀️ still, not bad!

[@TheeDoctorPig]

I can't even beat a sudoku with 12 numbers

[@ablejack3]

One hour, Eleven minutes! What do I win?

[@curtzeek8818]

Four minutes in and you haven't done anything, yet you have an ad up.

[@KevAlberta]

LOL thanks for the heads up

[@josepijamas1214]

Wtf does sanwiched mean?

[@Samgurney88]

The 9 on the 11 column could have been filled in much earlier.

[@mairisberzins8677]

AHah this only took me 1 hour and 56 minutes :( I feel stupid

[@giogiolachance4313]

classic brainiac

[@abdoroma6928]

44 minutes easy

[@taktikpur2546]

Took me fucking 1:46 h 😁

[@leovaris8738]

33 + 1 +9 = 42 Ok man Okok i know hes really good but still that caught my eye

[@Knlght0fZero]

The fact that its not a standard sudoku means this title is infact clickbait, bye

[@shereefmohammedgamaleldin468]

Okay, here's a small fact for you. Minimum number of digits that need to be given in a sudoku in order for it to have a unique solution is 17. Any standard sudoku with 16 or less will not have a unique solution. Never fall for any clickbaits again :D

[@tovi3280]

Bruh 33 + 1 + 9 = 43 right?

[@atheistsanonymous5376]

No you need 16 digits