Extreme Sudoku: Viewer-Requested Solve Of A Brutal Puzzle

Simon takes nearly 30 minutes to solve this requested puzzle. There are x-wings, finned x-wings and a swordfish so perhaps it's not surprising...

[@cmonkey63]

A rainy Sunday afternoon, Simon's calm voice walking through a difficult puzzle, and I'm learning. Call me a nerd, but this is fun!

[@ScarletMimic]

KZbin's algorithm sent me to this gem of a video. Very relaxing and softly entertaining, thank you for this Simon!

[@debralegorreta1375]

Learned a lot seeing how you feel your way around the puzzle. Excellent puzzle very well explained. Thank you.

[@thomaslong8401]

X Wings sure are easy to see when it's pointed out to me!

[@Blubb5000]

...or after 15 minutes of looking straight at them.

[@imransaifi2399]

Thanks Simon for solving this sudoku for me. I really enjoyed and learnt too much watching you solve this sudoku.

[@stridedeck]

I learn more from you struggling with these hard ones!

[@coxsj]

Very helpful seeing you looking for leads within the puzzle. Also appreciate that you solved the whole puzzle on camera. It is helpful to see the end game as well. Many thanks.

[@DaveGeelen88]

Thanks for solving these :D Can solve alot of puzzles of a decent level, but get stuck on these very hard ones :D Having someone show how to think, helps very much to reach the next level. Namasé Mucho Gracias I love you forever man Peace be with you

[@rabidsamfan]

Yay for the Nikoli puzzles to come. I really enjoy them.

[@juanvenegas5253]

ive always seen the x wing pairs. learned what they are called here and learned how to spot them better.

[@bingewatcher391]

wow!! That was definitely impressive!! You know its tough when takes a fleet of x-wings and swordfish!!

[@goster4070]

Thanks for the puzzle and hopefully more soon, Nikoli included!

[@leefisher6366]

Hi Magpie, I had no idea you were KZbinrs too! This should be worth watching.

[@ajaypoddar2705]

I love your videos on sudoku.

[@wossaaaat]

At 18:40, you had a uniqueness trick you could have used to limit those 3s a tiny bit, eliminating them from C9R2/5, although I'm not sure how that would have helped your solve (if at all).... I used it to eliminate possibilities, but I'd given up on snyder and populated the remaining possibilities by this point, slowly chipping away at them til I got to the solution.... brutal puzzle indeed. Took me almost 3x as long, but I got there in the end, which I don't think I would have been able to do before I started watching your channel. Thanks for all your work... even if it does leave me feeling woefully inadequate, haha.

[@lornavantilburg4622]

Did it in 28mins by using all your previous lessons.. helped as a distraction while dealing with the stupid flu lol

[@charleshultquist9233]

I like these symetrical design puzzles

[@danielspivak3926]

I managed to spot the 1s a bit differently around 13:00; if you look at column 9, it has 1s within your finned x-wing, so that sort of gives you a "triple wing" (if that's the correct terminology?), which is really the same as finding the x-wing on the rows.

[@nikarm22]

I’ve also noticed that way. I know this is an old comment, and you probably already know but The most I’ve heard it’s called “swordfish”. And when there are 4 rows or columns a “jellyfish”.

[@jasonoliver3548]

I love watching you solve these, it makes me more aware of x-wings etc. I would, however, like to point out that when you placed a 5 in row 1 column 6 (16:23 mark) that it was actually a bit of a guess because you only had one pencil mark there at the time. I watched that part twice, but please let me know if I'm wrong.

[@CrackingTheCryptic]

Delighted you enjoy watching them. I actually felt a bit embarrassed about this one because it seems such an age to take for a classic Sudoku puzzle. At the point you mention, I think the 5 was forced. The difficulty with this puzzle (and my solve of it) is that I am constantly switching between different types of pencil marks - which I appreciate must make it very hard to follow. At one point a little earlier in the video I'd started to look down column 6 for options and I'd discovered that r1c6 could only be a 5 or an 8. Therefore, when I finally figure out that there is a 4/8 pair in col 6, I know I can eliminate the 8 from r1c6 - which just leaves 5 as the last possibility.

[@msolec2000]

Okuyama is 奥山 (which means "remote mountain")

[@julieannmyers8714]

If you put your pairs in earlier, the unwinding goes much faster. (3,6 & 8,9 & 4,9) for example).

[@27scole]

It is interesting. I made a mistake and by that I think I can tell which way the 2s are in the first xwing you found. You ruled out the 2 in row 6, column 8. Now, I overlooked there is a 2 in box 9 and I found therefore a couple 2s in row 4 column 8 and 9. And by that I found a new couple 2s in box 5 by which I found that the lower xwingpart 2 can only be row 6 column 6. Now since I made a mistake, it has to be the other way round haha and I feel this is true because it always bugged me a bit about Sudokus this perfectionistic vibe, as much as I enjoy the logic of it.

[@27scole]

Ah I'm sorry you lack the wit to get it.

[@carlwessels4648]

Awesome

[@kiranagarwal7047]

Which software do you use to solve the sudoku I want it so that i don't have to waste time on writing and erasing pencil marks

[@dvoorganisation459]

Thanks Sir

[@goldenera7090]

is it true that once we find an X wing, then there must be a "reciprocal X wing" in the same boxes? what I mean is illustrated by this example. Simon found an X wing on 1 in r5 C3 c4 and r8 c3 c4.....but then he also found what I call a "reciprocal X wing" on 1 in same boxes ie boxes 4,5,7,8 in r6 c2 c6 and r7 c2 c6 can we use this as a general principle though? or is it a coincidence?

[@CrackingTheCryptic]

Just coincidence I think. Eg if you transpose a couple of columns you can shift the second x-wing into boxes 6 and 9 and out of 5 and 8 - which would make the x-wings not appear in the same boxes.

[@goldenera7090]

thanks Simon @@CrackingTheCryptic

[@judahmcnicholl8334]

at 6:40, why is it a 6, what is the logic preventing the middle bottom of that block also being a 6?

[@skenming]

6 is the only option in that cell, known as a naked single.

[@mrbrianakias1]

In column eight 2 5 6 8 are missing and in that cell 2 5 8 are eliminated yielding a 6 naked single

[@davidhimmelsbach557]

I thought that your swordfish quickly established Column 2, Row 9 as a "small 4" -- does this make sense?

[@motorhead1995able]

You missed the 1's sharkfin but the alternative solution was more instructive

[@AnveshKurapati]

Whats the app that's used?

[@Freeedy]

For once I managed to solve this puzzle under 8 mins ... I’m gob smacked!

[@deucedeuce1572]

How long if you didn't have to explain?

[@goldenera7090]

can you also solve yesterday's telegraph diabolical please?

[@CrackingTheCryptic]

Yes, I will try to take a look at it.

[@TheRealDrWho]

At 03:26 why pencil in the 2 in r2c6 ? Couldn't a 2 also go in r2c4, r3c4 and r3c5 ?

[@peternelson8876]

He was looking at columns 6 and 7, and checking off which spots a 2 would fit, he wasn't looking at the whole 3x3 box. (Box 2)

[@TheRealDrWho]

Ok thanks that makes sense now I also get why he eventually put the 5 at 16:13 and then the 2 in at 17:00

[@peternelson8876]

@@TheRealDrWho no problem 👌

[@christinebuckingham2480]

So if you just did the 1-9s in the puzzle in order you would find most of this early on. I don't understand why you don't do it this way to begin with.