Puzzle Description:

the x mark

#1: Sylvain "WCPman" (qwerty) on Sep 8, 2008 [SPOILER]

X are better looking when totally symetrical, but then you have to add detail inside or around to make them fun to solve.

Gotta LOVE these types of puzzles. :-(
No way to start solving, other than by guessing. It's clear from the title what this will be, so that at least helps. If you use edge logic, and start in any of the corners, it will work up to a certain point, and then you must try again somewhere else.

I don't know, I just kept going with my edge logic (bottom rt. corner) and never had to start again. I wasn't sure until about 1/2 way that it was right. oh well. ;)

OK, maybe I'm having a slow day, but I don't see how to use edge logic on this at all.

Well, I just started placing one of the corners and making an assumption that it went there. I never ran into any error (telling me that that original placement was wrong). Isn't that a form of edge logic? Placing a row/column of x # of pixels in one of the corners and going until you prove it wrong? I guess that some people call that trial and error or guessing. In this case, they all mean the same thing.

Nope. That's guessing. If you are doing edge logic right, then you totally KNOW that each cell you mark is correct.

However, it is natural to guess that the corners are going to be black, and if you do that the rest solves logically.

This is kind of like the "diagonal logic" thing. I know there is a unique solution, and I know what it is just by looking at it, but I haven't been able to come up with a sound logical procedure that lets me "prove" that those corner cells need to be black.

Yes, but in edge logic, don't you pick any edge row or column, and place it at either extreme of the edge/row, and start solving it until you get an error, thus proving that any number of spaces are to be given a small dot?

so true Jan. I just kept going and saying...maybe....maybe. So not true logic was being used.

Sort of, but I only look about two step ahead. If I'm placing a block in column 1, then I look at what cells that would fill in in column 2, and see if that is consistent with the clues for column two. This is something that I can pretty easily do without marking anything on the screen.

The whole "logically solvable" thing is a bit of a fuzzy definition (as has been discussed many times here) but to me it basically means that I wouldn't run into trouble if I were doing the puzzle on paper in ink. Things like edge logic and smile logic are cases where you can figure things out with only a little looking ahead, no more than fits in my mental buffer, but I suppose people's mental buffer size varies. If people can play chess in their heads, I expect they can solve paint-by-number puzzles in their heads.

I have never admitted to being able to do that far ahead all in my head. That takes extreme talent and brainpower. I don't think we will ever be able to reach a consensus on what logically solvable means. I am sorry for bringing it back up. Anyway, this puzzle requires "guessing" in some form or another.

Hopefully this X is on a treasure map and we need to get shovels to find the buried treasure chest.

Goto next topic

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