darn it, I think my brain has shrunk

i'm stuck!

Done

go

my browser had an interesting loading problem... showed this expert as to be empty of any given numbers :)

hmm - might be easier that way... :)

or not! LOL... haven't made my own sudokus yet. But refreshing solved that part of the puzzle...

wellp the first 5 cells from crasshatching were easy-enough... time to see what this expert is all about...

got 8 filled now and still not hard

halfway and kinda stuck

ditto, 18 filled... im afraid greens arent going to change anything, but time to try em...

good idea

greens didnt help - dont see any chains/wings that i can understand - going red/guess now...

greens did help here, am seeing the light at the end of the tunnel... now I only hope it isn't a train

cool, congrats... *keeps dropping red-crumbs*

got it. Thought I had a unique rectangle and hit red, but I could go back and find the mistake.

neato - my first guess hasnt solved, nor conflicted - i hate that...

you'll figure it out, as ever :) GL and cul8r

ciao...

ooph - conflict, finally... i hope *goes back and starts the other side of the red-trail*

going purple

:-D

done, but i needed three guesses - sigh...

i tried plugging this one into scanraid and i honestly have no idea how it solves the thing even tho it tells me every step... apparently unique rect does apply (i still dont get this one), but when it got to *an evil strategy*, it looked like voodoo to me... gl everyone...

Just to reiterate, Unique Rectangle emphasizes the rule that a proper Sudoku has only one solution, thus if those four cells all contain the same two candidates, then that Sudoku is invalid. Make more sense or confuse you more?

i always have trouble deciding what-can-be-eliminated in a UR, one? both? either? (apparently not) i only seem to understand it when the squares are xy,xy,xy,xyz... its all voodoo, i say... j/k

Difficulty score 41. I did a lot of guessing.

You're applying a difficulty score to something you guessed? Does this mean that your criteria for difficulty is the difficulty of the guess?

lol - the computer gives the score. the human (tries it indep of computer) needs to guess... :)

Instead of worrying about other people's credibility, I should actually rest my head on a pillowy star.

To H: what is scanraid? how do i acquire one?

irv, it's a website dude, scanraid.com

go

I think there will be a few LESS ELITES tomorrow morning after this one!! A real head scratcher!!

It's got me doing singles chains right now.

Go. Well, I got one cell without greens.

Oh you'll get a handful before you need to green.

done

That's pretty good, Bunny.

Did you guess?

Well, I guess there's no shame in going green at this point.

I just made a move that seems logical, but that I've never seen documented anywhere.

Oh, there was some shame! I forgot to check for loners.

Ok, no, my logic was apparently illogical. My logic teacher says that too, in fact.

Back to madness.

hey hey

slice, what was the move you did?

Well, I have two aligned cells with 3/4 in them, and two parallel cells with 2/3/4/5 and 2/3/5/6 in them, I concluded that in order to avoid the 'deadly pattern' those cells must either be 2 and 5 or 2 and 6, which leads me to infer that one of them must be '2' and so I can remove it from another cell that the can both see.

However, it broke the puzzle.

er, the second thing should be 2/3/4/6.

meaning it made it incredibly easy to solve, right/

er, ?

No, it didn't do anything at all, in fact. But I found another identical pattern somewhere else and did the same thing, and _that_ made it incredibly easy to solve and subsequently broke the puzzle.

ah, okay

yeah, I've done something like that on a couple of other puzzles (I forget which), although I have no idea if there's a name for it

I'm looking for a death blossom now.

a what?

A horrible, horrible maneuver that should never have to be used.

Also, the lack of (unlocked) bivalue cells in this puzzle is aggravating me.

yeah, I'm still early in this puzzle, but I've only found a few

All the 7's in the lower half seem significant, but I can't see how.

I've exhausted the possibilities of an xy- or xyz-wing, wxyz doesn't look too likely based on (again) the lack of unlocked bivalues. Singles chains led to nothing, though I didn't try every number, only those that seemed likely to give me something.

Almost locked sets and aligned pair exclusion are next.

Well, I'll take a break and come back to this later when my brain is less fuzzy.

I _will_ find the solution. I'm too stubborn to force anything.

Yes, I guessed :)
Sorry, the kiddos are runnin' circles around me.

this one has me worried; even when I'm making correct moves I don't think they're right, but I just broke open a little bit ... and I'm seeing a cascade beginning

Done! Had to use greenies and made 2 educated guesses but after that everything fell into place.

at this rate, I'm going to have greens in every cell before it's all said and done

The majority of moves I know depends on unlocked two-value cells, and this grid just doesn't have that many.

yeah, as do I - I have a few random tricks I can do with cascades (I don't know what their actual names are) and some three-valued cells, but this is just kind of a mess. I'm resorting to that trick you mentioned earlier to see it that unlocks anything (although I do have to ask: were the values you used there values in the puzzle?)

ah, yes.

okay - then I either haven't reached there yet or I'm going about it differently, I don't know

Starting with R6C3 and R6C9, head south two rows for the other two cells, just don't use it on the 4/5 pair nearby, that's what broke it for me.

In fact I could remove '3' from a certain cell based on what broke my puzzle, but I'm not doing it because that's illicit knowledge. lol

okay .... you're still a little ahead of me then. I can see that I'll eventually get to that spot, but I'm still missing some knowledge that'll let me eliminate a number from each of the other ones (not the R6 ones; I have those)

I have the entire puzzle greened (manually, of course)

was that a 2/3/5/6 in one of the cells? I just got something else

no, the cells are 2/3/4/5 and 2/3/4/6

okay, that makes way more sense

I mistyped the first time around.

yeah, I was looking at it (missed something that could be column-eliminated - whoops!) and realized that either my puzzle had bit it or there was a typo :)

okay, now I have to find the other time this occurs :)

...which I can't seem to do, I don't think.

does this incarnation need those matching bivalue cells? I only have a couple of instances of them right now, which may be the issue, and neither of them match up with anything corresponding

(...I think. I do have one potential match, but that resulted in a dead end, I think.)

Whoops, sorry.

It builds on unique rectangles.

I think I may be familiar with that term in practicality, but not in theory, if that makes sense

You can't have a square sharing the same two values because they would be interchangeable and the sudoku would not have a unique solution.

4 boxes can't share the same 2 values?

Right.

okay - then I did see it correctly

unfortunately, this leads to another more depressing conclusion ... I screwed something else up, maybe.

In this case, if we look at the locked pair of 3/4, we can see a rectangle formed by two other cells that also share 3/4, but that have other values.

yeah, I see it - I actually did see it earlier, but I think I have another problem with the board that's going to cause me to have to restart

Both of those cells can't reduce to 3/4 or else we would have a rectangle of 3/4 which is broken in and of itself.

...oh. wait, just kidding. I made the same assumption twice.

Thus, one of those cells has to not be 3 or 4.

yeah

and then that causes a bivalue (?) match with another cell, which allows the break in this case

Now, there's no documented unique rectangle strategy for four-value cells.

it should be able to be done in theory, but I'll have to figure out how later. even though I think I have this broken, I may have to go back in a minute and restart

But I built on the logic involved with a type-4 rectangle (I think) and made an assumption that since those two cells can't reduce to 3/4, they must be some combination of either 3 or 4 AND either 2 or 5 and either 2 or 6.

And actually, breaking it down like this is making me see why it's not a logical move. heh

....yeah, I am. nuts.

unfortunately, every time I attempted to solve the puzzle from that point I hanged myself. I'm starting over.

I applied the same logic using the 4/5 pair in the botttom-center box along with the 3/4/5/7 and 2/3/4/5 cells in the lower-left, which is where my puzzle broke and I decided that my idea wasn't going to work after all.

so in other words that idea doesn't work, or it does? you've totally confused me now

It does not.

in general, or just in that particular instance?

Logically, there's nothing that says I can eliminate the candidates that I did.

Therefore it's not a valid technique.

okay

wow, solved it by accident

Solved it with a jellyfish.

a jellyfish on what number? I'm willing to try it..

(hi peep!) pop on IM

go

done

go

good lord...

here goes nuttin'

man, March 28, 2006, hardest puzzle *ever*

done

done

definitely not an easy one

done. plugged this into Sudoku Susser (Mac app) to get some help. Unfortunately, it suggests lots of comprehensive chains which are, essentially, guessing. Wish I could have gone without the guessing.

Okay, I've read the posts, and nobody seems to have a solution without guessing. Here goes nothing......

Hmmmm, lots of nothing. 11 filled in, going manual green.

expert? i predict a large amount of sucking in my immediate future!!

I'm with you moe. Greens helped some, 18 filled in. But nothing left to try.

looking back through the days comments is discouraging. don't do it!

I agree. Jellyfish? This late on a Saturday night? No way...

making a few guesses...

whoops!

gonna tackle this one later tonight. getting a few beers might not make the puzzle any easier, but I won't care as much! :D

It hasn't helped me. See ya...

Done. Had to guess. I hate guessing. Maybe tomorrow I will find time to to figure out a real solution.

expet...ouch...can I beat the clock