Did This Sudoku Make Us Cry?

We were told this puzzle by the great Phistomefel might make us cry... did it and, if so, why!? You can play it here:
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Rules:
Normal Sudoku rules apply. Cells separated by a knight’s move (in chess) cannot contain the same digit. Digits on a line between two circles must lie between the circled ends (ie greater than the lower of the two circled digits and lower than the greater of the two circled digits). The digits along an arrow add to the digit in the associated circled cell. Digits can repeat on the arrow if allowed by the other rules.
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Hi! We're Simon Anthony and Mark Goodliffe, two of the UK's most enthusiastic puzzle solvers. We have both represented the UK at the World Sudoku Championships and the World Puzzle Championships.
Thank you for watching!
Simon and Mark

[@ldubls30]

I am petitioning for phistomefel to make a puzzle titled Simon's Coloring Book.

[@queenofroses09]

I second that!

[@leporid257]

@@queenofroses09 doch

[@mikesummers-smith4091]

@@queenofroses09 Ik auch.

[@matthewender3473]

Coloring is pretty useful! Not necessarily the bit tried at the beginning, but the 8/9 helped some, and around minute 53, I found a quicker end by using (well, highlighting) inference chains with cells that see all-but-one of the candidates in another box.

[@pandagirl7144]

Not many comments but I’m down

[@wossaaaat]

Me: There has to be a 6 on the ring, put a 6 on the ring... that blue can't be 4, remove 4... come on Simon. Also me: No way I could place a single digit on this puzzle before the heat death of the universe. You're a genius.

[@lezzly8581]

This ^^^ 😆

[@alexpridham6759]

Agony with those 6s normally i can get past it but it was so long

[@idannen]

This is me. I was mentally screaming about the 4, but I could never solve this by myself.

[@simsim4910]

Just imagine thousends of CTC watchers screaming there's a 6 on the ring for 8 minutes straight ^^

[@codyd6515]

@@simsim4910 This is me. Yelling at the screen to see the 6 on the ring. Over and Over until he does

[@seanmcdermott2035]

Me: Looks at length of video Also me: Sees creator Simon: Do have a go... Me: Nah, you're good

[@WanderingWolfe]

Hey, I did it. Didn't even take me an hour. It took way longer than an hour, but I still did it! lol

[@pulsefel9210]

@@WanderingWolfe the fact your comment and their comment was a year apart for me says loads. id still be going

[@WanderingWolfe]

@@pulsefel9210 LOL, no kidding. Honestly, though, I just found the channel a few months ago.

[@86larsonrd]

OK, maybe I have not solved the puzzle but I did figure out that those hexagonal shapes are shields. Why? Because they go between knights and arrows.

[@malvoliosf]

Three whales fall out of an airplane. Two fell on the ground, one fell in the water. Ba-dum, tsssssss

[@philtherealdeal2435]

Spoiler alert... The airplane was travelling over some icebergs at the time of the unfortunate jettison, so two of the whales landed on ice ground and one hit the water.

[@DaleKingProfile]

Simon always talks about us shouting at him and I have to say the SaS (shouting at Simon) index was very high on this one

[@freyadunn2621]

The 6 in r8c2 was sat there for so long and he even looked right there only to use some other logic, we love you Simon! 😂

[@jodyflint6843]

Before he noticed that 6, I think he made an error with the “blue/34” logic? (Obviously the 6 rules it out, but I think that square was an option for the blue).

[@fvizeus]

@@jodyflint6843 the logic was correct. He noticed R7C3, R7C4, R9C3 and R9C4 all had to be different and the possibilities were 3457. The blue square (R7C5) also had to be chosen from 3457 and was looking at 3 of those 4 squares, the only exception being R9C3, so that's why it had to be blue.

[@jsora03]

He pencil marks R8C2 and R9C2 without realizing a 6 needs to be on the between line. Then immediately afterwards discerns that R5C2 is 4 due to the same logic.

[@nathansikkema215]

@@jodyflint6843 There was a 6 in c3 so no 6 in blue

[@jodyflint6843]

@@nathansikkema215 why is this a "highlighted reply"? I think it's the only one in this thread that doesn't answer my question. 🤣

[@martinepstein9826]

Amazing and brutal. If you don't see the exact move Phistomefel intended everything just comes to a grinding halt. IMO you should delete colors when they've served their purpose, unless it's near the end of the solve. Less visual clutter.

[@joern122]

I think that depends on how well you can scan for colours. I am better at scanning for colours than numbers. So I use colour quite liberal when solving these puzzles. To me it is better so have 5 specs of colour in a cell instead of five numbers (but that might just be down to my pathetically bad eyesight xD )

[@gregs2284]

"I can do more with 8s" me: yay, he's finally going to look at box 8 "Only a little bit more, let's look at box 1" me: :(

[@helmiyliniemi1367]

So true :D

[@slurve0h]

Point of puzzle: between two lines Simon: finds logic to fill in every OTHER square instead

[@G0KAD]

Don't be too hard on yourself Simon. That's the job of the setters and of course, us viewers silently screaming and poking at the screen. Brilliant puzzle and a great solve.

[@SneakyFatKid7]

I agree. No need for him to beat himself up when he misses something. It is fun for us when we notice something Simon misses and makes great content.

[@seachicky913]

I’m obsessed with this channel. I feel like Simon is basically Giles (from Buffy) and I love it.

[@mightworth3735]

What is it about?

[@NothingButLiving]

This is spot on and needs a shout out

[@GotG113]

Simon is much cuter than Giles though, imo 😊

[@kilimanjarocruz660]

Simon would be a great Watcher, indeed.

[@xoxjanjounxox]

That is the perfect comparaison! Lol

[@sheauwn6974]

2 in box 9: *can be placed by Sodoku and knight's constraint* Simon: *eliminates every other digit to place the 2*

[@colinfun]

Wow this is the first time I have CRUSHED Simon's time with just over 20 mins. He really struggled with the whole 1 number per place on the between lines and limited options for the addition lines.

[@luketurner314]

Fun fact: that 6-cell "O" shape is a stable configuration in Conway's Game of Life

[@mightworth3735]

Quote of the day: "this just doesn't seem to be enough information. It is nowhere near enough information, Phistomefel!"

[@thechaospope]

This one was good, but I preferred "You can't repeat digits on the between line, so this is 4. I remember that logic from the prehistoric ages at the start of this video."

[@mightworth3735]

@@thechaospope I missed out in that

[@ueliriegg]

he graduated from "this can't possibly have a unique solution" one or two years ago :)

[@MixR700]

I particularly enjoy the long videos where a little suffering happens because I watch these at work on night shift, so the hour long videos really help the time pass.

[@maverickstclare3756]

willing the 4 and the 6 though the screen begging Simon to see them on this great puzzle

[@TPH250290]

After pointlessly colouring the Between Lines at the start, it would've probably helped Simon to colour them in the second half of the puzzle, as he just seemed to ignore the lower Between Line requiring a 6 and the various other restrictions on it.

[@ragnkja]

“Oh, is that what I’ve been missing?”

[@ragnkja]

@Tejesh Patel We’re just joking about Simon’s tendency to ignore the obvious in favour of the complicated.

[@wariolandgoldpiramid]

51:00 me yelling at the screen: "dude, all the digits on the between line have to be different! That means you have a 357 triple, and can just fill it in the other two cells with a 4 and a 6 !"

[@littleschnitzel8226]

I feel like mirrored cells (or their absence, rather) are Simon's doom. If he hadn't been looking for them so much, he'd have been solving each puzzle in just half the time he does. Simon is one of the most clever men out there, but he is so easily enchanted by red herrings. :)

[@robinisomaa]

66 minutes! I usually don't even bother with the puzzle if the video is over an hour, but I did this time. And it was worth it!

[@rdmprotey]

Anyone else yelling at the screen for the longest time for Simon to put the 6 on the blue line in box 7?

[@JonathanKelley1979]

It is so cute watching Simon be so giddy to do a Phistomefel puzzle.

[@pardox28]

I took my damn time with this & didn't once look at this video to help me solve it when I got stuck. I cannot believe I solved a Phistomefel puzzle solo, but I did. Thanks for the practice between-lines puzzles, Simon, they really helped me be able to solve this one today.

[@heathermichaelson3526]

"Maybe I'll just do a quick one... let's see what the new one that just posted is....... OVER AN HOUR FOR SIMON????? Nevermind"

[@laurenstephens1945]

The most exciting part of my day is when you upload. Thank you so much for doing what you do!

[@AngryViking234]

The 2 deduction at 47:30 is better by tracking that 2 has to be on the line in boxes 7 and 8. Because it's on the line and the 2 in r5c3 prevents r7c4 by knight's move there's an effective x wing on 2s in boxes 7 and 8.

[@quaby5308]

I love how at 40:25 Simon refers to highlighting 3 possible position for a digit as being "reduced to highlighting madness in the grid"

[@MisterM2402]

It's amazing how the knight's move constraint keeps combining with other constraints to produce beautiful new logic. It's surely the most versatile sudoku variant rule.

[@adamheywood113]

It's okay man you got this, we're all here with you

[@ivanramadhan3376]

24:26 show us how his brain works. He can process that complex thing in a few moments. Love that ❤️

[@NowUndefined]

I can't even imagine what Phisomefel's mind must work like to come up with the logic to create such a beautiful puzzle. Thank you for allowing us to join you in solving it

[@andrewnelson2525]

Love Phistomefel. I got off to a brilliant start, then when I was working on 2's my eye skipped over the grey circle in r2c6 as a possible candidate and broke the puzzle. I'd done so much long protracted logic by that point I couldn't find where I broke it. I started over and was happy to solve on the second try in two hours. That Simon solved in one hour with no missteps is amazing no matter how much I was saying "remember to put a 6 on the between line".

[@andrewgrant6516]

Come on Simon, pay attention! There's a 6 between 1 and 8, and only one cell it can go in. You crack the safes but don't pick up the money sitting on the floor in front of it.

[@amoswittenbergsmusings]

That is one of Simon's many charming traits. He despises the riches of this world and revels in the rarefied atmosphere of the worlds above us mortal humans. He just prefers battling with angels and demons over picking low hanging fruit, to mix some metaphors.

[@glennmelven3414]

What would be the fun in that?

[@KalOrtPor]

Took me three times as long to solve this, but the little scanning things like noticing the 6 has to go in, or marking 8s in box 3 and immediately recalling the 8s were marked in the top row of box 1 are things I'm good with and why I breeze through very easy puzzles with the best of them.....But then I'll get stuck on something that's more involved, banging my head for an hour on things Simon and Mark usually end up spotting within a few minutes. Stringing complicated logic chains with multiple constraints together isn't my problem, it's usually when you have to stop and say "Can this be this, why not?" or "What's wrong if I do this?" like figuring how to place the 9 in box 2.

[@blackbot7113]

Me: *watches baffled as the puzzle gets solved when I wouldn't even have known where do begin* Also me: "I saw one move Simon missed, therefore I'm very smart!" (The bottom left 6 at 58:00)

[@arewhyinoh8595]

21:04 if you look at boxes 1 and 4 you can highlight a few things, C1R5/R6 cannot go in the same box or the same column, and the 2 numbers in those positions must appear on the in between line. So you know C1R5/R6 have to go into C2R2 and C3R3 and C1R3 pairs up with C2R4.

[@markp7262]

53:35 finish. I started coloring en masse a bit before Simon did, and it definitely helped at the end. 3-7 pairs had to have the same digit as 3-4 pairs, and other such logic appeared to finish it off. Fun fun fun!

[@federicocucc7852]

Another sublime sudoku from Phistomefel , I actually found it more "approachable" than others, but still a solid 45 minutes needed

[@DJarr216]

Let's be real, every Phistomefel puzzle makes us cry. Tears of joy when we finally have solved them.

[@tabularasa0606]

And tears of joy for the beauty of the logic. They really are logical masterpieces of art.

[@xJONNYFATXMOSHx]

1:00:35 Simon - ‘Oh, I can put a six here, that must have been sitting there for a while.’ Me, finally seeing something before him, as if I could even begin these puzzles - ‘I’ve been saying that!’

[@zincfive]

I think it's easier to spot things when you aren't leading the solve, teaching others and filming yourself at the same time

[@isaacpianos5208]

You think so?

[@matthewgentry-hornet1946]

I can never do the sudokus but love watching Simon solve them. Definitely been screaming that the 6 in the bottom left has the be on the line in box 7 for a good 10 minutes though!!

[@bristolrovers27]

Brilliant puzzle Simons solved in his inimitable style, missing a couple of simple scans but producing some death defying logic to make up for it Great Chanel I’ve hardly missed a day this last year

[@garanceadrosehn9691]

There were times in the last 15 minutes where I figured out the digit for one cell before Simon did, but I am also absolutely certain that if I had tried to do this puzzle, it would have taken me *days* to figure it out. Seems silly to mention how I might have solved two or three of the cells a minute sooner than he did. This puzzle requires logic capabilities far beyond mine. Another impressive job from Phistomefel!

[@Raven-Creations]

That was a beast, but in a masochistically pleasurable way. 51:14 - two questions you should be asking: 1. the top between line has a triple, what happens if I eliminate 357 from the rest of the line? 2. Where can 6 go on the bottom between line? Nine minutes later, after much floundering, the penny drops (also after missing the knights move on 4 on blue for too long).

[@RichSmith77]

"Would you be surprised if I wrote a 9 in to the grid there?" (24:25) Since that's where I got stuck, I'd have to say yes, yes I would. Until I paused the video and could work out for myself why r9c1 couldn't be a 9. That was the one hint I needed. Excellent puzzle.

[@amoswittenbergsmusings]

My daily meditation to Simon's soothing sounds is up! Hold all calls.

[@stephenromano8413]

The 2 in r7c8 was there for so long, you could have found it using the logic from the 1-8 between line :)

[@wariolandgoldpiramid]

At 5:00 - I have spotted something interesting about the two arrows hat start in in Box 6. By sudoku rules and knight rules, all 5 of those cells have to be different from each other! Now 6 is impossible, because 123 would kill both 15 and 24. 7 is also impossible, because 124 kills 16, 25 and 34.

[@justanotherforsenboy1651]

It puts the cry in CRYptic

[@matthewender3473]

4:35 'And that seems to be about as far as the arrows take us.' At least until you look at how all *5* cells on the arrow see the others, which restricts the circles a good deal more

[@gregs2284]

At 55min in he does the most complicated thing imaginable with mirroring cells and colouring when you could just write in the 6 on the line. The one cell in the entire puzzle that had a clue on it that he wasn't using and steadfastly insisting on ignoring.

[@harmvzon]

“Would you be amazed if I would put a 9 here? “ That deduction with the 9 was insane. How fast did he see that? Incredible

[@ryaneakins7269]

I was just reading Martin Gardner's original article on John Conway's "Game of Life", where they called that shape a ‘beehive’.

[@derekfordyce9]

I see "Game of Life", I thumbs up. I'm a simple man.

[@darreljones8645]

When I was a kid, the only "Game of Life" I knew was the one sold by Milton Bradley.

[@cameranc.3244]

I love that this channel has become Simon fan boying over not only the sudoko but the setters. It really encourages both the setters and the solvers. If it was just about the sudoku itself it wouldn’t have become as popular as it has.

[@amoswittenbergsmusings]

At approx 49 minutes: 6 on the lower in-between line is in box 7 in c2.

[@gi0nbecell]

How did Simon always forget about the distinct lines, remember it, then forget again? The distinct digits alone would have told him the position of 6 in box 7, because he needed one on the line, and the other positions were ruled out. Just one example. Edit: I wrote that comment at about 45 minutes in the video. Seeing that this disambiguates all the other 6es, and combined with the logic on 3s and 4s, this was indeed a crucial bit of logic. I admit, I would probably never found a way to start this puzzle (like many others on this channel), but usually when I start from a position Simon gets stuck after the first few digits, I manage to see the rest. Which I would never have achieved before I started to watch this channel (and especially Simon, as Mark is often a bit too fast and too „biforcaty“). Thank you for this!

[@tzampini]

That is one HARD puzzle! And I love watching Simon solve it. It's mesmerizing to watch. Thanks for entertaining us with your brilliant mind.

[@RealCadde]

36:55 Another way to think about that is... One cannot go on the blue line because it would have to have a zero in one circle. And one cannot go in R3C5 because it is seen by knights move by the one in R5C4.

[@wokkawicca]

What an incredible journey this puzzle proved to be! Solved piecemeal over 2 days, forgot to pause the timer so no idea, but it was hours. Just loved how the logic of the 3 different elements flowed together. I have no idea how you conceive of something like this as a setter, but it was a pleasure to tackle.

[@skid68]

Simon is so happy when he can place colors :) Why does Simon make it look so easy for him and then like he helps use some time with marking up where he knows it is an "8" then keep marking up until he thinks we seen it and pointing at the screen say it is "8" there than 8 , 8, 8, 8 with me/we then missed that it delivered all of them :)

[@carollaw21]

At 36:08, you finally gave me the last clue I needed to solve this after what felt like hours of staring. It was a knight’s move, of all things. Somehow, I always miss those.

[@amoswittenbergsmusings]

57:02 Simon *says* it! On the in-between line he finds a quadruple 3457 which *immediately* places the 6 - which was available for some time already. [edit] 1:00:28 Simon finds the 6. I can stop screaming at the screen.

[@serebix3685]

Same thing for me with the blue which was clearly not a 4 for a long time because of the knights move from box 4!

[@sebastiaanb2651]

The 6's looking into the blue line (ever since the 6 in box 4 was placed) have had it up there for far, far longer

[@tehcanadianbacon314]

51:55 "I'm surprised that's not resolved, there's probably a 6 looking at this position" ... I was like yep - and then was surprised when he didn't stop to see the 6 in box 8 and 6 in column 3 which forced a 6 onto the line. lol xD ! Simon's mind is something else, I can't solve these puzzles without his help and he gets hard things so quickly! But the simple deductions can take some time

[@thanoshadtherightidea8724]

That 6 on the line teasing him for so long had me screaming at the scene. JUST PUT THE 6 ON THE LINE!!

[@Vuya_]

That was first one, that took more, then an hour to Simon, that I did myself) Before was able to do all by myself only puzzles, that took Simon under 40 minutes. Right now I’m the happiest person alive) And never felt so smart)

[@ShDragon1]

"It's stunning! It just makes me feel stupid." I have never related with another human being more in my entire life. :)

[@buzzly108]

*1:18** **_Rules_* *3:21** **_Let's get cracking!_* *19:44** **_First Digit!_*

[@soremekun]

No bobbins? LOL

[@robertbeeson3181]

Very often simple solutions to cells are overlooked, as you tend to stay on your current line of thinking. Try making a recursive approach, fill in a digit, then go back and see what impact placing that digit has before you carry on your current train.

[@helmiyliniemi1367]

Me looking at the 2 eights in box eight and therefore the number eight's place in box nine for 15 minutes before Simon finally saw it 30 minutes into the video... 🙄😯 But it's fine because I know that he always apologizes when he finally sees something that we have probably seen for a while 😊🙏🏽 Great video as always!

[@HenrikKleist]

50:04 when you placed 4 you removed pencil marks from box 1, then you have 357 triple in box 1. Due to digits on a line between two circles can't repeat, then you can remove 357 pencil marks from box 4. Which gives 4 in middle of the box 4 and which in turn gives 6 in upper right corner of the box 4. See, I'm learning from you :) Edit: You spotted it in 52:16

[@lainverse]

Digits can repeat on the arrow... but the other rules will send a complaint. I love how he made that into a clue to check arrows immediately.

[@thomaskang6562]

The 2's were actually far easier to figure out once you finished the 1's 8's and 9's but you missed some beautiful logic. At 41:10 in c4 the 2 cannot be in r3 or r6 because of sudoku and knight's move, meaning it is either in r4 on the arrow or in box 8. In box 8, however, the 2 cannot go in r7 due to knight's move, and it cannot go in r9 because it would rule a 2 out of every spot in box 7, and it amazingly cannot go in r8 either, because it and the 2 in box 5 would rule out every single spot for the 2 to go on the 1-8 between line. This gives you the 2 in c4 on the arrow, fixing the arrow, which limits the 6 in c6 to going in row 7, this puts the 2's in c6 into box 2 giving an x-wing placing 2 at r3c7, and that disambiguates all the 2's in the grid.

[@HuLech]

26:27 "Vienna". This is why I love you man

[@torknudsen2316]

No knoledge bomb today. I feel cheated. How can I no possebly know what 1-9 adds up to.

[@k13m13]

It doesn't add up. 1-9= -8. Just sayin' ;)

[@space_hobbit]

the thumbnail reminds me once again of the delightful fact that Phistomefel is an anagram of Mephistofel, a german name for the devil :D

[@adityajogalekar2376]

i believe thats why the thumbnail

[@stephenbeck7222]

It’s definitely an intentional anagram. I think someone pointed out the term has its own literary history, including as a character in the original German novel known in English as the Neverending Story (which was adapted into a popular movie).

[@jovi_al]

@@adityajogalekar2376 yes, that's what he said

[@space_hobbit]

@@stephenbeck7222 oh that's cool, I never read the neverending story :o there's definitely a character called Phistomefel in a different German novel, by Walther Moers, though I don't know if that one has been translated to English... it's where I know the name/world play from anyways

[@nerdiconium1365]

Also, there’s something wrong with the thumbnail on mine because for Simon’s video, it doesn’t show the one they made and you’re talking about. It’s doing the default thing with showing a frame sometime into the video. All the other videos seem fine so I wonder what’s wrong here

[@mightworth3735]

Simon: please, can we get further, now? Phistomefel: enough further for today

[@pedrobluis]

When you've pencil marked 6 on box 7, you should have spotted that 6 should be on the between line.

[@eliminator7ful]

Hmm. You solved a fifth or so of the last part of the puzzle in the last two minutes! Amazing to me, Simon! Many of your videos are like magic tricks to me, even though you explain every thought along the way. I love your apologetic demeanor. You are positively the most humble genius puzzle solver ever. Beautiful spirit! Very brave too, taking on the computer puzzles. I began watching your channel a few weeks ago to learn about Sodoku. Watching your vids has enabled me to tackle level 4s in that short time. I love to learn by watching. Great work. I watched one of your times Sunday crosswords too, and learned how to approach the solution of those in the first sitting, though they are very difficult. Thank you so much for mentioning my home state of Idaho in the United States when trying to solve one of your recent Sunday Times crosswords!

[@Dynamic_Pupil]

It took 104 minutes instead of 1 hour and 4 minutes... but this was my first Phistomefel solve where I didn't need Simon's narration to get "unstuck"! I played video at double speed to see how he went about it, and I was shocked! Simon DIDN'T color the grid as part of the final solve?!? (After solving 1s, 8s, 9s and getting down to four ambiguous 2s, I assigned colors to the remaining cells in the top in-between line. That line, column 3, and the nice dynamic between boxes 7 & 8 let me walk all around the grid using provable logic. Once I proved the 8 Arrow's 6 was "purple" [R4C3 in my model] that cracked the whole puzzle in short order.) Amazing puzzle, fantastic solve by Simon as always. Looking forward to the next norinori or starkiller!

[@Lantalia]

Fixating on coloring for a specific digit, when you have already identified the digit, is a waste of colors and a distraction

[@gc2009able]

I'm quite proud on this one-the only place I got stuck was with the 9's at 39:00... I didn't see that contradiction from the right angle. Granted, the whole thing took me like 2.5 hours instead of 1 hour! But I figured out the rest of the logic on my own. This channel has taught me so many cool ways of approaching Sudoku puzzles. I really enjoy Knight's Move puzzles especially.

[@dab1810]

At 58:16 Me: I've been yelling for 10 minutes to use the 4 knights move on the blue! Simon: I think I have to use column 6

[@fleurpalmer-paquis8226]

ive been screaming "USE YOUR EYES SIMON" about the 6 in box 7 for the past 15 minutes

[@leberm5577]

Amazing video simon, phistomefel is a mean constructor, his genius is humbling

[@bonneville1285]

I love the suspicion with the first digit, 19 minutes + Phistomefel? That seems too easy. ... 23 minutes - Normal service has been resumed.

[@FryuniGamer]

Oh God, I saw the 3 9s from the center circle nearly instantly and I was so mad at Simon for missing that

[@E4mj]

Wow, I solved that quite differently to you -- I think because I caught the 6 on the line straight away, which triggered off other things in other ways. Interesting! Always a joy to play along with you :)

[@mycroft64089]

It might have helped to color in the O shapes restricted to unique digits. After commenting on their beauty and using it to crack into the starting logic, going back to review that property could have speeded things along.

[@floydbloke258]

Thoroughly enjoyed this one. Chuffed with myself that I managed to solve it without help, although it was over a couple of sittings and goodness knows how long it took me.

[@wixxed]

That's so amazing the way you worked out the Red-257. I found it a totally different way. I don't remember how but I do remember pencilmarking all my 2's around the board and figuring out 2's later on. And even more amazing is that you ended the puzzle with 57's but I ended my puzzle with 37's!

[@laszloliptak611]

Brilliant puzzle. I was just wondering throughout the solve what the sum of the digits are in a row, column or box... How can you solve a Sudoku without knowing this????

[@nickburton5871]

What one needs is a knowledge bomb!

[@ueliriegg]

but... it's the secret!

[@Tiger21us]

I did it by myself without peeking into video beyond the rules section! First time on Phistomefel sudoku! Took me just under 190 minutes and was immense fun!

[@ExoKiller4]

Yes Simon, I can confirm that 6 has been sitting there for ages

[@richardmead9785]

Failed to see unique digits on the 2 long between-lines for a long time. Perhaps 20 minutes. Hard to play if deductions made early on are subsequently forgotten.

[@saanage3892]

My time: 70:58, I got stuck placing the 357s for longer than I'm proud of because I didn't realise R6C4 and R7C5 would have to be the same number. An excellent puzzle nonetheless

[@savola3129]

40:32 "highlighting madness in the grid, hoping it leads to results" is my entire solve strategy. :)

[@craigstocker5268]

I managed to complete it in 43:36. At 37:00 when you work out the 1 in r2c5, you can use the permutations of numbers that add to 9 to complete both arrows coming off the 9. i.e. There are 3 options: 1,2,6 paired with 4,5; 1,3,5 paired with 2,7; and 2,3,4 paired with 1,8. The only one that fits is the 1,2,6. From there the puzzle solves. Great solve in the end!

[@RichSmith77]

Why doesn't the 1,3,5 - 2,7 split fit?

[@DiMono]

I finished in about 1:10:xx. There was some interesting logic I found regarding 2s on the lower between line: Due to the 2 in R5C3, 2 on the lower between line must be in R8C2/5 or R9C4. However, R9C4 sees all three possible placements for 2 in box 7. That means the 2 in row 8 must be on the between line, which forces the 2 in box 9 into column 8, which then forces the 2 in box 3 into R2/3C7. Armed with that, when you place the 2 in box 1 you can circle the grid and finish them off immediately. There's also some interesting colouring regarding the honeycombs: R4C2 and R5/6C1 must appear on the between line in box 1, and R3C1 sees two of them, therefor R3C1 and R4C2 must be the same. That one doesn't get you as far, but I found it early and thought it was neat.

[@davideissler6162]

Love watching you solve but not one of your best days. I think Phistomefel has gotten into your head. At approximately 42:00 you wanted to rule out a 2 in r3c7. You could. 2 can not go on the between line in r1c5 as you can ‘t put 1 in the circle. Thus a 2 in box 2 can only go in r2c6 or r3c5 which are both seen by r3c7! Q.E.D.

[@Moolers]

I solved it before watching the video (obviously, but I usually watch the intro first) and was surprised to hear it's a 5/5 difficulty. It wasn't easy, but I've had more trouble with 3/5 difficulty puzzles recently and there's been 4/5 ones I couldn't even finish without hints.