Top Techniques For Classic Sudoku

[@robertsamuel1994]

The whole time I am watching these videos my response is: "oh yeah that seems logical, I could've seen that myself." So then I gave it a go, solved 1 puzzle in like 2 hours, so I tried another one and all of a sudden I'm like "where tf does that 5 come from!?"... def way harder when trying it yourself. There's a beauty in the swiftness of how Simon deduces everything without any mistakes.

[@aniketb2010]

Mismàs aqui.. whenever I see it online..Easy but doing it myself... WTF?? ;)

[@kuraban1]

Always feels good when you beat Simon's video time for a solve. Until you watch the video and see just how much time he devotes to teaching a variety of sudoku techniques!

[@Coyotek4]

I prefer to call these 'Rook Move Constraint' Sudokus.

[@akiya9216]

x wing?

[@Yamayeehaw]

Dhanan Balasaravanan that’s not a usual rule in sudoku

[@chiepah2]

Ah yes, the infamous Rook move constraint. It's a ... classic

[@nathanpohl5396]

Your diversions and goose chases regularly contribute to the expansion of my logic skills and are always welcome! Hope u do tackle tatooine. Looks as brutal as twin suns would actually be.

[@drhackchess]

You know.. pen and teller give an award when they get stumped. You need a cracking the crypitic stumped award for phillip.

[@jaeusa160]

The "Haven't Got A Scooby" Award.

[@blueberrypieology3088]

Interesting bit of logic with the three’s, thank you for explaining. I didn’t know that yet and as a beginner, am learning through these little sidesteps.

[@gregoryrodgerspowers8755]

What a missed opportunity! The "completely useless" technique you showcased WAS super useful, at that exact moment, if you just looked at the other columns. The 13 pair in Col5 combined with the 3's in row 6 eliminates the 3 from r3c9. Forcing the 3 into row1, which combines with the penciled 6's to give a 36 pair.

[@BramLastname]

So many words, And I barely understood half of it.

[@ArloLipof]

I bet Eugene Varshavsky finished both puzzles in under 8 minutes.

[@avisannschild]

So pleased with myself for spotting an X-wing in the first puzzle -- only the second time I've done that on my own! Was able to finish it without watching the video in 32:06, which pleases me too. Learning so much from this channel -- thank you so much for doing classics regularly!

[@ericbright1742]

I wonder if you could do a video on X-Wings, Y-Wings, and the other little notable tricks. Or if you have, maybe organize those videos into a playlist, and throw in that Phistomefel trick.

[@tryfail_failbetter]

Yes, please!

[@PH34RB]

There are definitely some that go into that, in detail. Mostly much older videos.

[@283leis]

they have done some, but they're super old now. it would be nice if they made updated ones with better video and audio quality

[@MrHighvolt]

i'd like that too :)

[@zanzaboonda]

Swordfish!!! I can't spot these for the life of me. Jellyfish, sometimes. Swordfish are my biggest struggles.

[@juliap1925]

Thanks for sharing- I was stumped on X-wing for the longest time, so your demonstration of it in this video was extremely appreciated.

[@necaton]

i somehow wanna see the video of him struggeling with the sudoku he couldn't solve more than anything else.

[@robertr7923]

@crackingthecyrptic how about something like failingthecryptic or cryptingcracksus or something similar. i think we could learn a lot from it.

[@TheofanisIII]

It was super hard. Took me 50 minutes or something while the one he actually solved for us took me just above 10 minutes. It involed multiple swordfish and almost 10 279 triples all over the board. I also had to use multiple basic chains like turbot fish and some more advanced chains and a couple BVC chains.

[@S_Black]

@@TheofanisIII That last part isn't needed. There are more basic steps like locked candidates, pairs/triples and maybe an X-Wing. Just lots of them

[@TheofanisIII]

@@S_Black Well, tbh I find chains to be easier to spot than hidden triples, which is why I took so long finding those damn 279 triples.

[@BrooksMoses]

I found the 279 triples and got all those filled in, and am still stuck at 1:30 in....

[@dmitryweinstein315]

1 hr 11 min for the second one... it is really one of the coolest classic puzzles, thanks Philip!.. the first one though I struggled with - you can get a lot of digits from the very the beginning but I didn't manage to keep the discipline of notation and blew it twice before getting the right answer...

[@carmieisenberg6850]

Best channel on KZbin

[@ThatGuy-dj3qr]

Thanks Simon. I always love your classic Sudoku solves.

[@julieannmyers8714]

11:08 with no special strategies (but never bifurcating). Can't wait to see the smart way to do this! You've really helped me get my notation more efficient!

[@keepmylittlesecrets]

First one was smooth and pretty quick, but that second one- OOF. Took me 2 hours and 6 minutes, but I did it! Spotted the swordfishes very early on, it was after all those initial swordfishes that took so much time. No bifurcation, though, so I'm proud!

[@debspimpisjim]

keepmylittlesecrets beat me by 1 minute. Good job.

[@dollarhyme]

Knowledge bomb! 4 not being 3 has already changed my life!

[@zanzaboonda]

Lovely. I really enjoy the variants, but it was refreshing to get a classic one again. Not only is it helpful for beginners, but it also serves as a guide post to see how much we've learned. (Getting better!) If you do post the other as a bonus, that would be great! Jellyfish are my kryptonite.

[@ianpearse4480]

Nice puzzle. Enjoyed doing it. I really like the puzzles you let us have a go at. 21 mins, so I am never going to be good at this but that was fun. Thank you.

[@philipnewmansudoku]

This made my day. :)

[@JosephPetersonJEEP]

Took me 2 hours to complete your puzzle, mith... and I feel like I did it pretty quickly for me, spotting things I normally struggle with.

[@ragnkja]

Your puzzle took me a good 48 minutes, and I probably spent at least half that time just colouring and pencilmarking, so it’s not an easy one.

Nice to see you again explaining classic sudoku techniques. 3 years ago you used a software with many mouse movements for switching between big numbers and pencilmarks and afterwards coloring while video cutting and so on... The web interface is a really big advantage!!!

[@keskinyavuz]

I am amazed how much and how quickly I learned from the channel. First one was done under 0 minutes and the second one around 45 minutes including some family distractions. My strategy for the second one was to highlight all the possibilities of a certain number, look for two in a column/row and grouping by each of these two possibilities and then removing the left-overs. Clear the color codes and repeat until I have pairs in boxes.

[@BigAsciiHappyStar]

Under 0 minutes? Even Eugene Varshavsky couldn't manage that!

[@glum_hippo]

Golly! That 'Tatooine' puzzle had a whole SCHOOL of swordfishes in it. Never seen so many in a single pile.

[@philipnewmansudoku]

A companion puzzle, Tatooine Sunrise: ......... 1....23.. .4..5..6. .6..7..1. 2....38.. ........7 ..95..... .5..6..7. 3....82..

[@Wecoc1]

On the same topic, I recommend this one by Klaus: ......... .17.2.8.3 ..3...2.4 .84.537.6 ......... .72.1...5 .48.715.2 .35.4.6.1 .........

[@sunriselg]

Thanks to your tip, I found five of them. But nothing else. No idea where to go from here. Edit: found a few triples, two more swordfishes and an X-wing. First digit after 55 minutes, then finished the rest in ~7 minutes.

[@paulcook2961]

Any hints? I'm trying it now. Found swordfish* with 5s, 7s and 9s and have each restricted to 2 positions per box. Where next? Suggestions welcome if you've solved it (or even just got further than me). * I'm guessing that is the correct plural.

[@philipnewmansudoku]

@@paulcook2961 As Judith mentioned, there are others to find. A small hint for both of you: Consider what some of them have in common. :) I have a full write-up, which I am happy to share if Simon doesn't end up tackling it in a later video.

[@doublepudge465]

Cracking The Cryptic: Blooper Reel This is a Video we Need !

[@blobdffoo819]

Oh wow i finished the first featured in 9:00, things are getting smoother after watching all the tips ! Thanks guys !

[@blobdffoo819]

The second one took me few hours ! And i lost some time because of a miswriting a pencil note (a 1 instead of 4 that screwed me a bit ahah)

[@Anashadk]

At last I solved one of the puzzles, the first one. I used one xwing, otherwise no other techniques. Now I am going to look to see how you solved it. Thanks for the entertainment.

[@littleschnitzel8226]

If it's some consolation for you, Simon, I solved the puzzle you gave up for over an hour, I had it almost finished and the swordfishes were beautiful- and then I accidentaly clicked the restart-confirm button and a ragequit followed. :)

[@stevesebzda570]

This was a really cool one. That x wing thing on the 2s you mentioned really did it.

[@AngelzWrath11]

I understand why you couldnt solve the tatooine sudoku. It took me over 3 hours to solve it. By far the hardest classic ive ever done. Id love to see your solve of it when you do it, to see what tricks you use to solve it more efficiently than me.

[@miniaturecolossus5242]

Regarding the pincers and pivots discussion at 12:00, it actually does give you something if you look at column 5 instead of column 8, as this allows the elimination of 3 from r3c9 giving a 3/6 double up in the corner. Doesn't help to solve the puzzle (you need the x-wing on 2s and the 1/6 double to do that), but it's a good example of the technique.

[@wonkywombat]

Being a newbie to this puzzle I really enjoyed it. The X Wing explanation helped a lot. Will watch again.

[@kn1nja]

Took me quite a while, but I managed to solve the 2nd puzzle in 2:25:35. Fun puzzle. Took over an hour just to get the first digit as others have mentioned.

[@sarahr.1076]

Ruleset was too difficult, couldn't solve it. :D

[@mightworth3735]

I didn't even try

[@HalfBakedLunatic]

Funny.

[@rebmcr]

I'd like to see solves where you struggle, it would make me feel better about my own abilities!

[@MsNosis]

thanks to previous solves and explanations on this channel, I found the X-wing on 2's in this one!

[@glennmelven3414]

Managed the first puzzle in just over 20 minutes. Tattooine Sunset, 20 minutes staring at the grid with just a few pencil marks and I just knew there was something going on with the 79s.

[@vishesharora2352]

Took me a loooong time, what a beautiful puzzle!

[@erikkubonhalvorsen4347]

I really loved the Tatooine Sunset puzzle. It is all about going about the "smart" numbers with Swordfish colouring until you can reduce the possibilities to create the twins and trippels. Took well an hour, but great fun :)

[@GPCTM]

Scary at first, turns to a very clean and well behaved sudoku. Kudos to the author.

[@nigelm5777]

The puzzle you’re stuck on STARTS with five (5) consecutive swordfish steps in Stuart’s solver. He rates it tough at 1551 which is a very high difficulty.

[@Gary21H]

Great lessons in this one. I like how Simon showed us the logic he was trying even though it didn't lead to anything, because when he got the the X-Wing, that opened up the puzzle for the solve. Often I'm left wondering "how did he know to look at that logic?", but this shows that it's all about asking different questions, and sometimes it will lead to nothing, but eventually you'll (hopefully!) ask the right question and get the solve!

[@JetPuff96]

Got the second one in 16:08, very satisfying to get one number and watch the rest fill in almost immediately, then back to unraveling.

[@catherinedresser5723]

You guys are great thanks for these videos, we are on lockdown again here and I enjoy getting stuck in : )

[@conexant51]

Funny how the start was so smooth then everything grinded to a total halt, and then that x-wing that blew everything wide open again and it was yet again smooth sailing until the finish. Great puzzle! Classic sudokus do have their charm.

[@davidbourke6211]

For Tatooine Sunset I highlighted all the cells that were on intersections of the half given rows/columns and center-notated all of them with given digits (beautiful pattern btw.) I then noticed there was only one 5, one 7 and one 9 in those cells. That led me to endless starfish (or possibly crosses between x-wing and starfish) which I'm calling *x-stars, rather than x-fish :) 2 hours of brute force logic later and I'm mentally exhausted but satisfied.

[@MyChannel910725]

Best time of the day, the longer the video, the better the day

[@quimmmus]

I also love Simon’s videos! They are great, I still don’t understand why though! Regardless of the quality of the videos, it’s quite sad what you say, isn’t it?

[@PaulReinerfelt]

Nice to see a classic sudoku! I don't care much for the variants. (Also, it has been ages since you did a cryptic.)

[@CameronWattMusic]

Managed the puzzle in about 50 minutes. Was a headache and I'm not very good at sudoku but I'm proud that I managed.

[@Kelters]

Thanks for running through the Pincers and Lever logic again. I remember I should look for it, but it often escapes me. So, although it was "completely useless" for this solve, I found it a useful revision of piece of sudoku logic not mentioned much of late. BTW, this is one of the reasons so many are happy to go through a standard sudoku solve at regular intervals. Thx. :)

[@SamAshworth91]

1:29 Tatooine has twin suns, not twin moons (it actually has three moons)

[@coyote4237]

Thank you, this was entertaining and informative.

[@Coyotek4]

26:00 for the first puzzle, but I will admit to bifurcating near the end, as I couldn't figure out the logical path to the end. EDIT: I need to get better at spotting X-wings!

[@Crocodile_Appreciator]

Yeah, I didn't spot the X-wing at all so I had to use much more complicated and slow logic to get to the end :c

[@alexbove106]

I didn't quite bifurcate, but I figured out something like the x-wing using the counterpart squares (which could have been 8's and would have affected the 2-8 pair Simon was focused on). Once you figure out that the bottom left square has to be either a 2 or an 8, the 9 in C2R8 is forced and the puzzle cracks wide open.

[@nickcorrado5105]

I didn't find the x-wing, either. A shame, since I was doing so well up to that point....

[@ragnkja]

Here’s a sudoku that’s great for practicing X-wings and pointing pairs: kzbin.info/www/bejne/i4KvfH6LlLGCers

[@dylansmillie7397]

Hi there, I really love watching your videos and I can watch them for hours they’re so relaxing! I would like to download and try your apps for myself but they’re $8 and I don’t have much money :( I do already have a sudoku app that I use but yours look really good and I’m considering purchasing them but I don’t know if I would like them or not. So I would suggest having maybe a 1 week free trial or even just a short clip showing off the app! There are a couple pictures on the App Store showing off what it looks like but you can’t really get a feel for it from just pictures. Just a suggestion :)

[@cgyrask]

It took me a little over an hour to solve Tatooine Sunset, and I'll have to say that is the hardest classic Sudoku I have ever done. It's chock-full of swordfishes and even a thematically appropriate x-wing, and at one point I had a minor epiphany that the digits given for the moons were in the pattern of a inverse jellyfish, but I was unable to leverage that thought into anything useful towards solving it. For anyone about to attempt it, I'll offer this advice to get started: Focus first on the digits that have at least 3 givens.

[@kenx1618]

quite a nice puzzle...happy i eventually was able to do it

[@michaelenyart5789]

I've never really attempted Sudoku before (other than a few easys and mediums online) and decided to try this one and I'm 90 minutes, about 23 placed numbers in, and completely stuck and unsure if I've made an error. Lol! Time to watch the video

[@NMalteC]

This is a lovely puzzle. I strongly encourage anyone to solve it without using pencil marks. There's only a single pattern that you must find. This opens up the entire grid.

[@mhoogev]

I am not an expert Sudoku player but seriously! i've solved the one you stuck on in the video, even without using pencil marks so i guess you can stare blind on puzzles too as i have seen you solve the most difficult Sudoku's..... how on earth you could miss it?? Keep up with the good work.

[@chrisheron3044]

They should make a podcast where they talk to different puzzle-makers and solvers

[@Grikkez]

I'm usually rather Luke-warm to standard sudokus and prefer doing variants, but Tatooine Suns is one the best sudokus I've ever done. The solution path (or should I say solution swim) is startling and I'm amazed that it's possible to make a puzzle with such a path to the solution. It was faster to solve than expected, but that is probably because I realized the theme of the solution rather quickly. Also, when I saw the puzzle I didn't expect my first digit to be a 1. (I got my first digit at about thirty minutes and solved it in under thirty five .) Hints below. Hints: Swordfish galore. Swordfishes on all digits except 1 with some cleaning up between swordfishes. Order of swordfishes: 5-7-9-6-2-4-8-3.

[@eduellery]

There must be something between 5-7-9-6-2 and 4-8-3. I could clean up a lot on the first set, but can't swordfish on 4s after that. Must have something happening - triples, x-wing, something...

[@Grikkez]

@@eduellery Yes, I seem to remember that I had to spot a triple or two as well (I think one was in the first row, but I could be remembering the details wrong).

[@eduellery]

@@Grikkez I got it. Swordfish on 1 (yeah) between the sets. Always cleaning up with doubles/triples after swordfishes. First digit is a 4 and from there it is quite easy. What a nightmare that was.

[@chiepah2]

I haven't finished yet, but I am trying Tatooine Sunset and I thought it would be interesting to point out that Phistomefel's Theorem can give you all of the -5's almost immediately- 7's and 9's pretty easily, 5's take a bit more work. (Simon should love that)

[@sonnyboywannabe]

Thanks for the Classics!

[@honigschlecker1]

Almost two hours for the second puzzle. Holy moly. 😀 Included some colouring, swordfish, X-wing, tripple, and a AIC/bifurcation which turned wrong after a loooooong time. That wrong path was pretty entertaining, though. :-)

[@yichen6313]

The second one is brutal! Full of fishes in the beginning... And after all the initial fishes come the real difficult part. I'm not sure how I got through it... (around 1h30) I would be extremely interested in seeing Simon or Mark go through the Tattooine Sunset puzzle

[@sunriselg]

I spoiled myself a bit, reading the comments. But I finished the second one in 1:02:46 - I set my first digit after 55 minutes, then the rest went very quickly.

[@bmomosaik]

i dont even play these any more not even sure why this showed up in my youtube list and i still finished it sub 35 mins well messing around... oh and i did it with the snipping tool didint get no nice software to type numbers into for me.,

[@negar1368]

Well for someone who has never able to spot swordfishes, the second puzzle was a pretty good practice! :)

[@BradJames878]

This is probably an older video, but the 'diversion technique" shown at the 11:40 mark has since been named a '2-string kite."

[@jimbomanno]

YAY! A classic at last. Thank you. I'll have a go now.

[@susanlemmey4012]

That 'pincer' is actually an empty rectangle. any offset pair of a number in a box can give that affect if able to 'look' at a restricted column or row. I found three (or four) of them on 3s in this puzzle when I tried it myself. and during your solve was staring at one that would create a 28 pair in box 3 (causing a 36 pair in the same box).

[@Wolfhound_81]

Total Sudoku beginner here and in the first seconds I'm like "wait, what? How do you know there's a 5 already?" :D Guess I need some beginner videos.

[@TonyNaggs]

First puzzle I was a little slow, no major issues. Second puzzle (Tatooine Sunset) was hard. I got some 79 pairs early on with slot machines, reduced some other digits to 2 or 3 alternate chains. But couldn't find a logical path to any actual digits, so I went back to the 7s & 9s and guessed a digit which quickly took me to a valid solution.

[@fermujica4600]

I spotted some of the swordfishes in the second one but... impossible for me. You better make a video solving it! Even if it's a long one I'm sure most of us would enjoy it :)

[@ericveneto1593]

That diversion was actually useful! Don't apologize Simon.

[@alienrenders]

15:30 for the first one. 45:01 for the twin moon one. The second one is filled with swordfish and many of those are created by forming pairs from previous swordfishes. Tedious start, but after a certain point, even with few digits in the grid, it just solves itself. Just very annoying doing swordfishes for almost every digit and then finding pairs or triples.

[@S_Black]

What you explain @12:50 is a 2-String Kite. Computer programs can certainly detect these

[@rm-rf]

I paused the video to try the Sudoku. Took me almost 30 minutes and I solved 4s and 5s among the last digits. Took you all of 10 seconds to find them all... :D

[@omer-x2j2z]

Solved the first, upper one in 28:37. Withou using pencil marks At timestamp 14:30 check which numbers are missing in column 6. That are 1, 5, 8. Row 6, column 6 already has a 5 and an 8, hence there must be a 1. A 1 there means that in row 4, column 5 there must be a 3 and in row 6, column 4 there must be a 7.

[@sebrofniloc]

Gratified to see Simon follow the same route as me, but got stuck at the point he pulled the X-wing out of the bag and referred to the video. Plain sailing from there - just wish I'd seen it for myself!

[@drengskap]

The puzzle by Rimu Takamura, I managed in 31:36, using your New York Times 'open flank' gambit to get started. Tatooine Sunset is completely impenetrable to me at this point ;-)

[@kayleawilson]

Rules were confusing lmao. Also hearing you gush about the Star Wars one made my nerd heart sing

[@Skeeto9]

17:30. Really happy with that time. I'm actually really surprised I was able to pick up that X-wing.

[@soyruba]

Yees same time for me, and I too felt like that when I discovered the X-wing! :)

[@rickcarter7495]

I saw the x-wing pretty quickly because when I had the 28 pair I looked over for empty rectangle possibility but instead saw the x-wing. It took a bit longer to see there actually was a good use for it. The solve after being able to apply it was quick.

[@FolgoreCZ]

1:29 Twin moons of Tatooine. Spoken like a true massive Star Wars fan. :-D

[@LightDhampire]

23:15 My best time yet! My first 1 was when I finished column 6 (from working 7's and finding 3's, I think).

[@rebeccanorth6349]

💕💕💕💕 whatever solve you do. Great entertainment 😊

[@ivanblackz]

Do more classic sudokus!

[@fubaralakbar6800]

11:35 I'm probably not the first one to point this out, but there is something at least marginally useful here. If V-7=3 (center block, southwest), then V-2=1 and II-8=3. But if V-7=7 then VI-9=3 and III-2=3. Now III-9 can see both II-8 and III-2, therefore III-9 cannot be 3. That only leaves 2 and 8 for that cell, which pairs with the 2/8 in III-1, creating a 3/6 double in III-2 and III-3. It's small, but every elimination counts!

[@davigurgel2040]

14:04 there was an actually useful thing you could have done with the 3s, but on the other side. In row 6, if the 3 is in column 4 it forces a 3 on r3c5, if it is not in c4, it has to be on c9. Either way, r3c9 can't be a 3, so it be forced into r1c8/9, making a 3x6 pair

[@maxoshiro]

Ok, so I managed to do the second one in 34:29 - I couldn't get a single digit for 25 minutes and when frustration overflew I started randomly choosing numbers from the notations I had. I know, unbelievably stupid, but I am amazed I somehow got it correctly.

[@Westez499]

Please Simon could you do the Tatooine sunset -puzzle. It is one of the only regular sudokus that has been too much for me. 3 attempts and still cant finish it.

[@davidcarlson7172]

Loved it!

[@jonathanharsh7434]

The first one took me 11:10 and I didn't need a single hint. I also didn't take hints for the second one, but that one took me over two hours so I'm not sure I can still classify that as a win.

[@henrym5034]

First one 46:01 Having to resort to marking all candidates, did some not-so-useful x chains. but after finding the 16 pair the puzzle cracked open.

[@alephnull00]

The first one took me 20:44, second one took me 1:33:21. Interesting!

[@luketurner314]

17:09 - With a hidden 2 x-wing in rows 1,9 and col 1,7 and a few naked singles

[@lavachickens]

newbie to the whole sudoku solving game. 27:38 for the featured one in the puzzle doesn't seem too bad

[@RandomBurfness]

I tried the second classic and oh boy. I had to use SEVEN Swordfishes, a bunch of hidden/naked triples, AND an X-Wing to wrap it up.

[@rogerstone3068]

Just when I'm getting the hang of the X-wing, you tell me I have to learn swordfish as well? Oh groan...

[@paulcook2961]

I'm trying it now. I found swordfishes on the 5s 7s and 9s and now have each in 2 positions per box. Where next? Suggestions welcome.

[@RandomBurfness]

@@paulcook2961 There's one on 2s and one on 6s. Then you need some pairs and triples, then you get one on 8s and then another one on 1s, then you get an X-Wing on 1s and THEN you get a naked single and then the puzzle collapses.

[@paulcook2961]

@@RandomBurfness OK gonna try each hint one by one. Didn't find swordfish on any other digit but I'll look at 2s and 6s now.

[@paulcook2961]

Oh I realise I HAD spotted the swordfish on 6s but forgot! But I missed the swordfish on 2s. Normally I wouldn't beat myself up for missing a swordfish but in this case, I was specifically looking for swordfishes on each digit, one-by-one!

[@a9b9c9d9]

8:34, but I'm almost certain that I made a faulty deduction at some point that just happened to work out. Not sure how long it would have taken otherwise, but definitely longer.

[@philm5872]

can you use the naked single rule to narrow a square to 2 numbers? So if A square sees all numbers except 2 can you pencil mark in these 2 numbers?

[@walkingwriter4325]

21:15. Best time yet! Guess I'm learning a few things. :D