Lacking QC – Messing a-round

Messing a-round is a 2D packing puzzle was designed by Alexander Magyarics and made by alienpuzzles.  It was 3D printed and used by Alexander as his exchange puzzle at the 41st International Puzzle Party (IPP).  The tray is white and each of the 8 pentominoes is made with a different color giving it a vibrant look.

The puzzle consists of 8 pieces that need to be packed in the tray although not all at the same time since the tray can only accommodate 7 of them.  The pieces are rounded and fit together nicely with each other.  However, 2 pieces are missing a couple of rounds and the pointy corners don’t fit nicely in the inside corners of other pieces.  Really, what has become of quality control these days?  At least these unrounded corners were discovered before distribution and the solution statistics were duly updated.  With these unrounded corners, the number of solutions for packing all the pieces except the T piece dropped from 128 to 1.  Similarly, the number of solutions without the Z dropped from 95 to 2 and the solutions without the L dropped from 19 solutions to 1.  It’s almost as if the corners weren’t rounded on purpose.

Although those unrounded corners are initially awkward, you quickly get a feel for what pieces won’t go together well.  Given that roughly 99% of the potential configuration are going to be eliminated by the unrounded corners, you begin to suspect that finding the valid 1 or 2 working solutions is going to be tough.

I experienced the expected almost solved situations several times.  The case where the last remaining opening for a piece matches a piece that was already placed and not the one in your hand.  And the case where the last piece in your hand would fit if only one of those unrounded corners had been properly made.

Of course, I started with the missing Z challenge since there were 2 solutions and it would be like finding 1 of 2 needles in a haystack instead of a single needle.  And sure enough, even though it took some time, I eventually found 1 of the solutions.  Challenge complete.  No, I didn’t feel compelled to search for the other solution.  It’s always there if my conscious starts to nag me but she’s usually after me to do other non-puzzle related things.

I did the missing L challenge next since T pieces are usually a real pain in these types of packing puzzles.   I found this one much more difficult than the missing Z challenge and it took a lot longer to solve.  In fact, I sat down with it several times without success.  I was relieved when the last piece finally went in to complete this challenge.

I saved the missing T challenge for last since I find that the T piece in 2D packing puzzles usually don’t work well with other pieces.  However, the T is so restricted in how it can work with other pieces that it actually supported finding the solution.  There isn’t much you can do with that T so it helped to narrow things down rather quickly.

If you like Messing a-round, Alexander has designed other puzzles where he’s forgotten to round the corners of some pieces.