Karakuri Packing

A couple of weeks ago I went away on holiday for a week and took a couple of puzzles along to play with – one of them was Karakuri Packing from Mine’s recent release – and boy was I chuffed with that choice – it has turned into one of my favourite puzzles in a long while.

Designed by Yasuhiro Hashimoto and beautifully made by Mine, it presents you with five pieces (some of which have holes in them) and two dowels to be placed in a box with a slightly restricted opening. A quick count will convince you that there should be more than enough space in the box for those pieces so it should be a simple matter of working out how to arrange them all inside the box…

And that’s where the fun starts…

I’ve often described the first step in my solving technique as getting myself to the point where I think a puzzle is impossible, and then working out how it might possibly not be… this puzzle did that to me multiple times – and that’s probably the main reason I’m such a huge fan of it – it gives and confuses and then gives again…

Having already established that the pieces should all fit in the box… I set about trying to do just that. Don’t get me wrong, it’s easy to find an assembly that would fit inside the space if the opening weren’t restricted, but that little strip across the top turns out to be quite confounding…

It turns out that the restriction and the shape of some of the pieces means you can infer quite a lot about where some things have to be – and that really feels helpful – only it turns out that it’s impossible to actually put them there and get the rest of the pieces into the box… hey ho – step 1.

At this point I was still swithering between a couple of potential assemblies and trying lots and lots of different things to gradually whittle down the possible approaches – until I was left with only one that I thought had to be the right approach – only there was no way to actually execute the assembly – step 1 - again.

Time to think not only outside of the box, but well-differently…. And there lies not only a little madness, but also gold dust it turns out – because there is indeed a way to get around the current blocker in that assembly process… only problem is that another blocker appears almost immediately after that…

Ultimately there is a way to deal with the final hurdle and the pieces just slide neatly into place…

…and when I saw that happen I got one almighty “A-Ha!” buzz that lasted for ages… it’s such a neat little puzzle that makes you Think (c) quite a lot… and as a result it’s become the one I’m currently most enjoying giving to other puzzlers to have a bash at – it is excellent!

Kudos to Hashimoto-san for the design, and thanks to Mine for bringing it to the attention of us puzzlers around the world.

King’s Day 2023

A few of us have been making the annual trip across the channel to Wil’s legendary King’s Day Puzzle Parties for a while now, and now that we seem to be past all the international lock-downs, Steve, Ali and I made the trip across once again this year.

We met up in Eindhoven where Louis picked the lads up from the airport and collected me from the train station (I’d flown into Schiphol). We checked into our hotel, grabbed a few puzzles and then headed to Louis’ where he’d laid out a fabulous spread for lunch. Well-feasted we hauled out the puzzles and settled into the usual routine of “Here you’ll like this one”, “That’s impossible” and “Aahhh, I really like that one!” with varying delays between them. (Louis’ delays tended to be a lot shorter than ours for some reason.)

I’d taken along my copies of Karakuri Packing, Chained Lumbers and Coin Wallet from Mine’s latest release knowing that the guys probably hadn’t played with them yet… they all went down really well, although Steve stopped short on one or two of them, choosing to delay any gratification in favour of respecting the designers… I’m sure that’s what he said.

Several of us had a play with Louis’ copy of Tri-Rodspan – a 12-piece co-ordinate motion puzzle designed by Bruce Patterson and modelled by George Bell. I’d printed out a set of pieces just before I left on this trip so I was keen to see how easily they went together – fortunately Steve was keen to see how easily Louis’ copy could be disassembled so I got the chance to assemble it. Unfortunately I didn’t pay quite enough attention to the colours and ended up reassembling them in a totally uncoordinated fashion… which set off some serious OCD twitching and a “proper assembly” was undertaken, only for Steve to spin it and start the whole process all over again…

I spent a while fiddling around with a copy of a tray-packing puzzle (Amsterdam?) calling for different levels of Dutch houses to be made in a frame… I managed a couple and felt quite good about myself until Louis promptly went and found several new solutions in a matter of minutes. (Apparently there are several challenges!)

Somewhere around 6pm Louis ordered a massive pile of pizzas which magically arrived at the door a short while later, so we feasted again… plenty pizzas disappeared include some of the famous cinnamon and sugar pizzas that were left for the dessert round.

At some point Mieke prompted us to see about playing an escape room and she and Louis then managed to find one that had a slot available for later that evening, so a short while after dinner we all piled into the car and headed off to a nearby town to help our mate Barry get his meth lab sorted before the cops raided it – and then we played an escape room.

The room had a few really good surprises – the first transition caught us all by surprise and made us all smile – there was some darkness-induced frustration in the second phase due to the flashlight we were supposed to have not being available as it was broken (as we discovered afterwards) and then the third phase was really well done… we made a bit of a meal of one of the main puzzles and that slowed us down a lot, but on the whole we cranked through it all pretty quickly and we enjoyed the room. It was fun to be on the other side of the law in a game…

Back to Louis’ for a little more puzzling before he deposited us back at our hotel for some sleep ahead of the main event on Sunday.

He duly collected us after breakfast and we headed off to Venlo where we were the first the arrive with Wil literally just having finished all his preparations. There were warm greetings and plenty catchings up over a quick coffee and tart before the rest of the known puzzling world began arriving.

The Monkeys had taken along a few copies of Burrly Legal to offload and custom-made Wil a six-piece Burrtle Opener to add to one of his collections – exceptionally well-played The Two Brass Monkeys!!!

The weather on Sunday was fantastic, so the outside tables were put to very good use, with Oskar in his usual spot with piles of new 3D-printed designs inviting anyone to have a fiddle. 

I spent quite a while getting myself hopelessly entangled in a copy of Rainbow Stairs – and just when I thought I was making some progress, Oskar sat down next to me and said “You realise that’s a variation of the Fifteen puzzle don’t you?” – a particularly cruelly-timed comment given I’d literally just got myself to the point where I needed to swap two pieces around… Thankfully(!) he went on to point out that it didn’t have the same parity constraints, so I might actually be able to solve it… and a while later I did indeed manage to align all of my rainbow’s stairs.

While I was doing that Steve was frantically twiddling the handle on Let That Sink In until it did in fact sink in (or out) and then Oskar talked us through the theory behind it – I loved the bit where he assumed we could all instantaneously multiply 7,11 and 13 in our heads while he was telling us about the design. (It’s 1,001, which is interesting because the opposing gears multiply out to 1,000…)

Several of us had a go at his Screw Gears – and I for one can confidently say that I did not come up with a helpful strategy for solving them – over dinner I did manage to almost assemble the screws in precisely the wrong order and I considered that a major achievement.

Michel was handing out copies of a safety pin challenge that I enjoyed playing with while I was writing this blog post – if you want to have a bash yourself, put three safety pins together in such a way that they won’t come apart, but if any one of the three pins is opened, all of the pins come apart.

It was great to catch up with Jan Willem again and to relieve him of a couple of old Karakuri boxes that he had spare copies of… and in time-honoured tradition when I went through airport security the next day, that was the one thing they were interested in! (I suspect they’re all closet Japanese puzzle box aficionados.)

I spent quite a while playing with some extremely rare wonderful old Karakuri boxes from Wil’s collection over the course of the afternoon – a rare treat indeed.

Frans was looking a lot less battered than he has been and it was nice to catch up with him and Rob and Goetz and Michel and Rob (yes, the other one) and Patrick and Christian… and no doubt several others that I chatted or puzzled with over the course of the day… and have forgotten to mention.

At some point the crowds began thinning out and when Wil received a call from his local restaurant he realised he totally missed his booking slot… we all bundled into a few cars and headed into town for another fabulous meal – with the obligatory puzzles on the table as usual. The food was superb, the company excellent and it turned into another night to remember.

Once dinner was complete a few of us ended up back at Wil’s for a little more puzzling and a lot more coffee – it’d been a long couple of days for some of us – before Louis saw us safely back to our hotel somewhere after midnight.

Thanks a stack to Wil for hosting us all on Sunday and giving us another King’s Day to remember and to Louis for fetching and carrying us over the weekend and entertaining and feeding us royally on the Saturday!

 <Some pics courtesy of Wil as I didn't take enough myself!>

Nine Balls

Another superb puzzle from the mind of Koichi Miura, brought to life by Mine.

You’re presented with (there’s a clue in the name!) nine balls joined into three pieces and invited to simply place them into the supplied frame, which is clearly large enough for the nine balls in a three-by-three layer. One of the pieces has a red dot on one side and a blue dot on the other and you’re politely asked to insert the pieces into the tray with the blue dot showing and then the red dot showing.

The only slight wrinkle is the placement of the two holes that allow the pieces entry into the frame – one on the centre of a side, and one in the middle of an edge on the top of the frame. There are also a few little holes around the corners allowing some scope for manipulating the pieces inside the frame – and no, that’s not a spoiler – you’ll work that one out for yourself in around three seconds flat – and if you didn’t, you might want to consider another hobby.

Once you start experimenting with the pieces you’ll find ways to get them all inside individually, but it’ll take a little A-Ha! moment to get them all in with the blue dot showing…

Getting them all in with the red dot showing is a little more challenging and definitely requires some outside-of-the-box-thinking.

I really loved the solution to this great little puzzle – it’s not one you’re going to spend hours and hours mulling over, but it will definitely put a smile on your face and give you a nice sense of achievement when you slot the pieces into the frame with the red dot uppermost.

For me this is definitely another puzzle that deserves to be called “delightful”!

(…and I managed to get through that without a single double entendre!) 

 

STOP PRESS

This just off the interweb: some bloke called Nick has discovered an alternate solution for the blue challenge that makes things more interesting... go on, get your copy out and find the other assembly - you know you want to... and yes, I did! :-)

 

Turning Quarter Hole

Another excellent puzzle from the mind of Hajime Katsumoto and the fair hands of Mine-san.

It’s beautifully open and honest – the name even describes it all pretty accurately: put the pieces into the box through the one quarter hole in the rotating cover. The interior of the box is two cubies high and the corners of the square box are cut off at 45 degrees to remove the corner cubies – leaving an octagon-ish space to be filled.

You’re told that the aim is to insert the three pairs of pieces to form a cross-shape inside the box, and a little experimentation outside of the box soon shows you that there are plenty of ways to do that… so far so good…

However, when you seek to transfer that construction into the box you begin to realise just how restrictive that opening really is… it only lets pieces go in in one way. Helpfully there are plenty of little finger holes to help manoeuvre your bits around inside, but there’s only so much you can do with the little opening.

The good news is that experimentation is richly rewarded in this little packer, and there are a few unintuitive things that you’ll find might be quite useful…

Then of course it’s just down to finding the most suitable assembly and working out how the heck to get it all inside. There might well be an obvious last piece to go in, but you’ll find that the order of some of the preceding steps might need more than a little thought as well.

I really like the fact that you need to use your wits on this one, it’s not just about bashing through all the possible assemblies – it’s also about experimentation and learning.

Thank you Mine-san for bringing this great design to life!

Katsumoto-san’s winners

Two new puzzles really stood out for me at this year’s Puzzle Design Competition – interestingly they shared a common theme and a designer: Hajime Katsumoto. And I wasn’t surprised when they both took a Jury Honourable Mention and one also won the Puzzlers’ Award in the 2016 Nob Yoshigahara Puzzle Design Competition.

They’re both excellent and if you get a chance to play with a copy, or pick up one of your own, you will not be disappointed! 

Slide Packing has a really simple premise – it’s one of those puzzles you can just leave out without any description or instructions and everyone will instinctively know exactly what the goal is… you’re presented with a box in two halves and a few pentominoes … so clearly the object to put the pieces into the box and close it up… simples! 

Anything but, actually!

The two halves of the box slide together on a pair of rails carved into the edges of the two pieces. The bottom half of the box will allow two layers of cubies and the top half will fit a single layer… the resulting space inside the closed box allowing for a full 3*3*3 cube. The pieces you need to put inside the box will only take up 20 of those 27 cubies – so there’s theoretically bags of space left over inside there once this thing’s solved… 

Hopefully I’ve convinced you by now, dear reader, that this is not only theoretically possible, but you’re probably thinking to yourself that surely there’s another catch… well there ain’t – that is it!

But when you start playing with putting the pieces into the bottom half and sliding the lid closed you realise the problem – you’re going to have to either put one of the flat pieces inside the lid and get the others into the bottom half of the box without any obstruction to the top half, which would allow you to simply slide the lid into place, or you’re going to have to manoeuvre things around while the lid is semi-open and hope you can get things where you need them to be…

Now when I first sat down with this puzzle it was pretty clear what you were trying to do, and I very quickly found that everything I wanted to try wouldn’t work. So I fiddled around for a while and rapidly ran out of ideas…so I did what anyone in my position would do and moved onto the next puzzle… but in the back of my mind I kept playing around with the odd idea or two… and the next morning I’d come up with a plan that I was thoroughly delighted to find actually enabled me to slide the lid home with everything neatly inside the box… my favourite puzzle in the Design Competition and also the one puzzle I’d save.(*) 

Penta in a Box consists of five pentominoes to be packed inside a neat little box with a hinged lid. Once again we have space inside the box for a 3*3*3 cube, so this time there will only be a couple of cubies spare once the box is closed… the pentominoes are also all different this time, which makes finding a 3*3*3 assembly a little more of a challenge!

Finding one is only half the battle, however… the hinged lid effectively swipes a little bit of the top front row of cubies because of the arc it takes as you close the lid… which is interesting because you know there are only two cubies spare in there, yet the lid will probably stop you using three of the cubies – and while it’s been a while since I did any really serious sums, even I remember that 25 into 24 don’t go good! 

Thankfully there aren’t nearly as many possible assemblies with this set of pentominoes so it quickly reduces to the problem of closing the lid and how you can cunningly remove the apparent constraint. 

Another puzzle that needs a bit of thought before the arrival of a massive “A-Ha!” moment…

Two terrific puzzles from Hajime Katsumoto – both were available from Mine’s webshop – hopefully more will become available in due course… 

...and it's not just me who thinks these puzzles are brilliant! - Read Kevin's thoughts over here... 

(*) At one of my earliest IPPs one of the veterans asked me which puzzle that I’d acquired over the course of the magical few days I would choose to keep if I was only allowed to save a single puzzle? It was a brilliant question! And one that we generally discuss every year now… This year it would have to be Slide Packing!

Thinking inside the box…

Caramel Box was a big hit at this year’s Nob Yoshigahara Design Competition, taking a Top Ten Votes Award for its designers, Mineyuki Uyematsu and Yasuhiro Hashimoto, while it amused a shed-load of puzzlers. 

I’d had a fiddle around with the competition entry and didn’t get very far at all, so when I spotted a few copies on Mine’s table in the puzzle party, I grabbed one. 

Caramel Box makes a brilliant pocket puzzle – two sets of wooden blocks each need to be placed inside the sheet metal box and the whole she-bang will easily fit in your pocket. 

The box encloses a 3*3*2 space and has an opening across the top (a 2*3 side). The only possible problem to get in your way is a single overhanging square in one of the corners. All you have to do is place each set of three pieces (both of which form a solid a few cubes shy of the required 3*3*2) inside the box so that they aren’t protruding out of the open end… how hard can that be?

Picking a set of blocks to start with (they’re different colours so you don’t unwittingly end up with a set of mismatched blocks) I decided that the best attack would be to find a 3*3*2 assembly outside of the box and then set about trying to work out how to get that assembly into the box – finding an assembly wasn’t too tough, but then exploring how to get it inside the box generated quite a few alternative orientations and rotations… sadly the first several assemblies didn’t turn out to be particularly productive, so I switched strategies and focused instead on getting to an assembly that worked inside the box.

Either I got lucky, or it turns out this is a more productive strategy, as I managed to reduce the number of alternatives I needed to consider quite significantly  and indeed stumble across a solution to the first set of pieces in a matter of minutes (pity I spent more than an hour on the less productive approach!).

Finding the first solution was a very rewarding “A-Ha!” moment – with a number of moves required to successfully manoeuvre all of the pieces into their correct spots to allow the final piece to settle into place. 

Fresh with a victory under my belt, I swapped to the second set of pieces and expected to find a solution in a similar amount of time… only to realise that there’d probably been a fair amount of luck involved in my first solution. 

The solution for the second set of pieces didn’t come as quickly and as a result, I was suitably satisfied when it did finally wander along. Once again, finding an assembly isn’t the real challenge, it’s finding one that allows you to fit it into the box and then reverse-engineering the choreography required to actually get the pieces in there…

This is one of those deceptively simple little puzzles – everything's on show and there are only a couple of pieces to contend with, yet it provides a pretty decent challenge – and the fact that it’ll fit in your pocket makes it dead easy to lug around to torment others with… it’s a great puzzle.

[See what Jerry thought of Caramel Box over here.]