I Don't Understand The Difficulty!

Chiral 2&2 by Koichi Miura

Sigh! I have been working on this puzzle for since I got it in amongst a large batch from Mine way back in February 2021. Yes, that is 5 years! It has been in my work bag for the whole time and I would take it out to play with it at least once every week or two and even let colleagues play if they showed interest and could be trusted not to use force. It never got solved. It's a pretty simple challenge. There are 4 tetrominoes (2 pairs of chiral shapes) to be fitted into a 3x3x2 box through a diagonal opening in the top. There are no other holes or widening to be useful. It really shouldn't be that hard. 

It certainly should be clever because it won a Jury honourable mention at the 2021 IPP design competition. Usually puzzles that are incredibly tough don't do particularly well in the competition. It requires a solution to be beautiful or unusual or really clever. Despite the supposed lack of extreme difficulty, I just couldn't seem to solve it. I had tried what I thought was every possible move and every possible assembly and just failed every time.

Always easy to get 3 of the 4 pieces in!

Usually after a period of several months, I remove failed puzzles from my work bag and transfer them to the desk in my study or one of the various caches of unsolved toys around the house. But I hadn't done it with this one for several reasons. My study desk is now so completely covered in stuff I either haven't solved or haven't gotten around to putting away that I daren't add any more for fear of the whole leaning tower coming crashing down. The other puzzle stashes are starting to annoy the present wife (actually they started that about 3 years ago) and so I am trying not to clutter them up more. So, I kept on trying week in and week out.

Recently I have received some rather amazing complex toys and have been working on them:

Emerald Vault

Rune Lock

Two fabulously beautiful challenges from Dedwood crafts - I haven't managed to solve any of Dee's puzzles for a very long time. I don't know why - maybe I am rubbish at puzzles?

Gravity Box

I need my lunch

These fabulous challenges take a long time for someone as dim as me and so I need a few nice quick and easy puzzles to write about as well. In desperation with nothing to write about after I spent 7 hours writing the on-call rotas for our department, I decided to torture myself with something that I had failed on for 5 years. What could possibly go wrong?

As usual, start outside the box, make some shapes that will fit in and see whether they can be taken out piece by piece. There is a very specific set of requirements for the pieces to be removed. I was able to cut down the solution set quite quickly and found a few positions where 1 piece would easily be removed but a second would be impossible. I also (for the 100th time) found a nice arrangement where 2 pieces were removable. Now I needed to work out how I could get the remaining 2 into/out of the box. It was going to need rotations and they were going to be hard to find. There really isn't much room for manoeuvring once one piece is inside. Nothing seemed to work! I found a few nice possible rotational moves but either they wouldn't work when another piece was inside or they took me in the wrong direction. Aargh! I vaguely remember Derek (remember, he's the genius) mentioning to me that one of these puzzles from Mine required a coordinate motion. So I tried that and also got nowhere.

I spent yesterday evening muttering to myself and still failing. Aargh! This morning, I had a nice lie in and came downstairs nice and refreshed - ready to crush it and write up a wonderful review. Mrs S and I have got on board with this intermittent fasting thing and don't eat anything until about 1pm. She duly came into the kitchen for breakfast to find me with my head in my hands and muttering to dark oaths to myself and wishing I had some hair to tear out. As any good wife would, she laughed at me and said I was useless at puzzles and should give it all up. This made me sit up and drop a piece into the box where it sort of fell onto its side in a way that I hadn't thought would be possible.

OMG! By taunting me, she had forced me to find a new move! 

AHA!

Don't look if you don't want to see a spoiler - otherwise click on the button for a solved view.

Why had I failed for so long?

 

I had suddenly found a wonderful move that should have been perfectly obvious from the very beginning. It wasn't even that difficult a move but I had not been able to see it for all those years until a combination of desperation and ridicule made it possible. Maybe I need to get Mrs S to make fun of me more often? Maybe not!

Burrtools tells me that there are 10 possible assemblies of the pieces into the 3x3x2 shape but only 2 (mirror images) are possible solutions. I didn't use BT until after I had solved it.

I can see why it won the honourable mention. It is not actually that tough but is very clever and well hidden. I just love almost everything that Koichi-san designs. He's a genius too!

These come up for sale periodically on Puzzle Paradise and it's definitely worth getting hold of a copy.