Top This!

Ok, enough with the self-indulgent meta-posts and back to our regularly scheduled puzzling. Another one of the puzzles that I got from ThinkFun was Top This!. It looked like an interesting variation on the usual assembly puzzle, so I thought it might be fun to try.

Top This! consists of two sets of pieces, one is orange and the other is blue. Each set contains two copies of each of the five tetrominos, which are the five ways of arranging four squares. The puzzle was invented by two junior high students from Taipei, Yu-chuan Lin and Chun-yen Chou.

Each of the challenge cards shows you two orange pieces and two blue pieces, and your task is to arrange them in the same shape so that one could cover the other. In the harder challenges, you have three pieces of each color to arrange.

A pretty neat concept, since usually with assembly puzzles you are trying to make a predetermined shape out of a set of pieces. In this puzzle, you don't know what the final shape is. Instead, you need to figure out how two different sets of pieces can make one shape.

Another interesting thing about this puzzle is that it demonstrates how approaching a problem from a different angle can make all the difference. Sometimes I would try in vain for several minutes to arrange the blue pieces in a way that the orange pieces could cover them. Having no luck, I would then try to arrange the orange pieces so that the blue pieces could cover them and would solve it almost immediately. You wouldn't think it would make a difference, but it really does.

As with all of ThinkFun's graduated puzzles, the fourty challenges start out with beginner, intermediate, advanced, and expert. I got through the beginner and intermediates pretty quickly (maybe 30 minutes or so). The advanced were a bit tougher, some I got pretty quickly and others I spent a few minutes on. The expert ones were a bit tougher, as you would expect. I think I got through the whole set in between 1 and 2 hours.

I don't want to give too much away, but somewhere among the challenges is a neat little trick that stumped me for a while. I thought it was great that they only put it in once, since it really caught me off guard!

One thing that I didn't like as much about this puzzle was the feel of the pieces. I think a denser plastic would have been preferable to me. Also, I'm not a big fan of the bag to hold the pieces since I'm a little OCD and the bag doesn't fit in tidily with my other puzzles. I'd rather a box or something for them, but that would drive up the price.

Overall, Top This! is a neat little puzzle at a very reasonable price. Definitely worth checking out!

100th Post!

Whew, that's a lot of posts! Thanks to everybody who has been reading this over the past year! I couldn't have kept it up without all your positive feedback. I've had a great time writing and look forward to plenty more puzzling adventures in the future. Since I'm a numbers guy, here's some statistics:

• Pages: 260
• Words: 76,634
• Paragraphs: 830
• Sentences: 4,010
• Flesch Reading Ease: 70.4
• Flesch-Kincaid Grade Level: 8.0
• Page Loads: 29,426 (712 per week)
• Unique Visitors: 17,191 (416 per week)

It as been very cool seeing folks visiting from all around the globe. Since I've started, there have been visitors from 104 countries from Argentina to Vietnam! Here's a snapshot of where recent visitors have come from:

If you're sick of checking to see when a new entry has been posted, take a minute to sign up for the email notification on the right and you'll get an email every day there is something new to read.

If you're just joining us, here are a few of my favorite posts:

• How it Started
• A Curiosity Awakened
• Building My First Puzzle Box (my most popular post)
• Frand's Mind Bender (Part 1 and Part 2)
• My Puzzle Nemesis Vanquished!
• Stewart Coffin Visit

Have a favorite of your own? Post it in the comments below. Also, if there's something you like or don't like, let me know in the comments or contact me, and I'll try to make the next 100 posts even better! Thanks again for reading!

River Crossing

I recently had the chance to do some puzzle testing for Tanya Thompson at ThinkFun. If you're not familiar with ThinkFun, they're an awesome company that is responsible for bringing a lot of interesting puzzles to the masses. They're probably most well known for Rush Hour, but they have a large product line of other great puzzles as well, many of which have won numerous awards.

One of the products I tested was the 2011 refresh of River Crossing. It has a completely new set of 40 challenges, so they had some testers going through them to make sure they were classified appropriately and to see what we thought. In other ThinkFun news, they are also releasing 2011 refreshes of  Rush Hour, Tip Over, and Chocolate Fix! Each will have all new challenges, so that should be plenty to keep you busy for a while.

As a thank-you for helping test, they sent me a few free puzzles, which was quite kind of them! I was thrilled just to get a sneak peek at what they are working on, and the puzzles were a bonus. One of the puzzles that I received was the original River Crossing, and I was quite interested to see how it stacked up against the refresh.

In River Crossing, the objective is to get the Hiker from one side of the river to the other. There are stumps that are arranged throughout the river and planks that connect the stumps. The Hiker can pick up planks and put them down, but they must fit exactly between the two stumps (the planks are 1, 2, and 3 units long). The only catch is that he can only move planks that he can walk to: no hopping between the stumps. A bit confusing to explain, but it is quite intuitive: you can even try out a few challenges on the ThinkFun website. The puzzle concept was designed by Andrea Gilbert (check out more puzzles on clickmazes.com) and the physical version was created by Bill Mitchell. Graham Rogers and Serhiy Grabarchuk also contributed.

To make it easier to play, the planks have magnets in them, and so does the hiker. This lets you use the hiker to pick up the planks, which was pretty handy. It also keeps him from falling off while you're thinking. Tanya mentioned that the refresh wouldn't have magnets, so I'll be interested how it compares.

The puzzle comes with a plastic base with a bunch of holes in it, and the challenge cards are large enough to fit over the base. There are holes in the challenge card where the stumps are supposed to be inserted. The starting location for the planks is indicated by a shadow, though the shade of the shadow isn't much different from the shade of the water, so on several occasions I forgot to insert a plank.

It can take 30 seconds or so to switch challenges because you need to pull out the stumps, switch the card, and then put the stumps in. This isn't too bad, but for the easier ones you might spend as long setting the puzzle up as you do solving it.

Since I did the testing of the refresh the online version of the puzzle, I was quite interested to see how the physical version worked. In all, I think they did a really good job of it: the pieces fit snugly and it is easy to pick up the planks with the magnetic hiker. It takes a bit of getting used to, but is quite efficient once you do a few challenges. The hiker's bold hands-on-hips stance is quite fitting and cute graphics on the challenge cards are also nice.

The challenges are very well classified into different difficulty levels. I thought that they did a particularly good job in the first few Beginner challenges. Each one teaches you a little bit more, so you're sure that you understand the rules. The difficulty gradually ramps up as the complexity increases and you need to add more tricks to your repertoire.

I think that since I had already gone through the 40 challenges in the refresh, I found the original version to be a bit easier than I would have otherwise. I think I got through the whole thing in about 2 hours, and it probably would have taken me another hour or two if I didn't have some practice on this type of puzzle first. Still, I think these puzzles are slightly easier than the ones in the 2011 refresh: the refresh had a few that stumped me for 20+ minutes, which is a good thing as far as I'm concerned.

This puzzle was good at demonstrating how thinking backwards from the solution can help you solve a sequential problem. Sometimes it isn't obvious how to start out, but you can see how the end must go and work your way backwards. Even with this tactic, the advanced challenges can be pretty tricky!

I enjoyed it so much that I purchased River Crossing 2. I'll write a separate review of that later, since I'm still working on it. It is more difficult and adds two new types of challenges that are quite interesting as well.

Overall, River Crossing is a very cool puzzle and quite reasonably priced. Definitely check it out if you're into this type of puzzles!

Stanley Puzzle

Fellow renegade puzzler, Peter Wiltshire, found The Stanley Puzzle in Hoffman's Puzzles Old And New, a book published in 1893 that catalogues most of the puzzles available in the 1890's in London. Peter made himself a copy, which he brought to IPP29, and at the urging of a few interested collectors, decided to make a few more. In all, he made 7, one of which I purchased from him on PuzzleParadise.

Here is the entry in Hoffman which describes the puzzle. It was stamped from brass and bears the picture of Sir Henry Morton Stanley, known for his exploration of Africa. He also supposedly uttered the famous phrase "Dr. Livingstone, I presume?" during an expedition aimed at finding the Scottish missionary and explorer David Livingstone.

Peter's version of The Stanley Puzzle is made out of aluminum using a jigsaw and a file. It has been polished to a good shine and looks quite nice!

Upon receiving the puzzle, I started working on it right away. The purpose, of course, is to remove the ring. At first, it appears impossible, since both of the flat pieces are too large. With a bit of fiddling, I was able to figure it out without too much difficulty.

I brought it over to a friend's house yesterday, curious to see how difficult they would find it, and both of the folks who tried it were able to solve it without much trouble.

I think the only downside is that the solution is a bit simple for my taste, but I still found it enjoyable. This will be a good one to show to people who get frustrated easily, since it isn't too tough. Overall, a nice little puzzle!

More Small Boxes from Japan

A while ago, I wrote about a few boxes I got from the Karakuri Club's Small Box series. I really enjoyed these puzzles, and they're quite reasonably priced so I decided to order a few more. I tried ordering #4, #5, and #7 (the only ones that were in stock that I didn't have), but they replied that they were also sold out of #4. Oh well! I'll have to grab that the next time they decide to make some.

My order arrived a few days later (I'm always amazed by how fast things arrive), and I eagerly got started working on them. I like doing things in order, so I started out with #5 first. It had the telltale rattle of a hidden mechanism, so I had a feeling that it was going to be pretty tricky. After a few minutes of making no progress, I decided to switch over to working on #7.

The Karakuri Small Box #7 was quite nicely crafted, as are all the boxes from the Karakuri Club. It is made out of Katsura and Teak. One thing to note is that the Karakuri emblem is not inlaid, like it is in the rest of the series. Instead, it looks like it was stamped with a hot implement. Still, it looks nice!

I inspected the box briefly and was able to discover the first move quite quickly. It is a bit unusual, which is required for the way that the mechanism works.

On the website, the description says that the second move is 'unexpected' but I found it to be pretty much what I expected. Perhaps it is slightly different than more standard Japanese puzzle boxes, but I have seen it several times before.

After this, I was unsure how to proceed. Nothing else moved that I could find, so I spent a few minutes wiggling things trying to figure out how to get it apart. All of a sudden, it popped apart in a pretty unusual way, which is always a nice little surprise.

I think it took me about 10 minutes to figure this one out, which is longer than the other boxes took me, if I remember correctly. I think most folks will be able to figure this one out without too much difficulty. Overall, a neat little box!

Now, back to Karakuri Small Box #5! I neglected to mention that this box has a slightly different appearance from the others. This one has a 'base' at the bottom that you can't really see in the picture. This box is crafted out of Maple (KK-5-2).

Here's a snippet from the description on the Karakuri Club website that I found intriguing:

Even though you try to open it in your hands, it isn't easy to open. You may not think you need a desk, but it sincerely is helpful to solve the puzzle.

This definitely piqued my interest, so I was eager to see how it worked. As I mentioned, since the box rattled when I moved it, I was pretty sure that there was some kind of hidden mechanism involved. As such, I tried all the standard things you try with a hidden mechanism puzzle: I tilted it, I whacked it, I shook it and I spun it in various orientations, all to no avail!

I sat and thought about it for a bit, and tried to peer in the slight gap along the bottom to see what the mechanism was, but that didn't help much. I fiddled around with it a bit more, and quite surprisingly it started to open! However, my finger slipped and it shut and locked again. Darn!

I tried to reproduce what I did before, and I was able to get it to open. Unfortunately, the mechanism was not visible, so even opening it doesn't reveal the secret. Eventually, after playing around with it a bit more, I was able to get it to open reliably. The solution is quite clever and it must be an interesting mechanism that enables it. Very cool!

I was quite satisfied with this box as well. I found it to be fairly difficult, I think it took me a good 10-15 minutes to figure out. I'd be curious to see how my non-puzzler friends find it. I'm looking forward to trying out the rest of the series: I still need #4, #6, and #8.

Octagon Box

I recently purchased Octagon Box from the last CubicDissection auction. It is a Bits and Pieces reproduction of Pile of Disks by Akio Kamei. I had seen it before on Rob Puzzle Page, where he lists the many Bits and Pieces boxes he has purchased over the years. He said this was one of his favorites, so I was happy to see that Eric was selling it. Jeff also did an entry about this puzzle.

There were a few cosmetic issues, so I got a pretty good deal on it. Two of the joints are separating a bit, and it has a few dings on the top. Still, the mechanism works quite well, so I'm quite happy with it. Photo by Eric Fuller.

Visually, it is a nice looking puzzle. The laminations are quite well done, and it has a nice finish on the exterior. There is a nice bevel running along the top and bottom edges, as well as between the lid and body of the box.

Oddly, one segment of the laminations that is supposed to be dark ended up looking light, which kind of throws things off a bit. I thought that this might be a clue at first, but I think it was a mistake. Still, it is fairly well crafted for a Bits and Pieces box.

It took me about 3 minutes to figure this one out, but I think I got lucky. I took a glimpse of the mechanism, thought that I understood it, and then put it back together. Much to my surprise, it didn't work quite like I thought it did. After another 5 minutes I had it open again, and this time I studied the mechanism a bit more.

The mechanism is pretty clever, there are a few little details that were included that make it a nice puzzle. There are some dead ends that sort of give you a hint as to how it works. The one drawback is that solving it can feel a little random, but that is frequently the case with hidden mechanism puzzles.

Overall, a solid puzzle! I'm glad that I was able to find it for sale.

T4 Popplock

I recently read Jeff Chiou's blog post about some puzzles he borrowed from Jonas Bengtsson, one of which was the T4 Popplock by Ranier Popp. I have seen his awesome looking puzzle locks online, but haven't purchased one yet since they're pretty expensive. Jeff ended up buying a T4 after he borrowed one from Jonas, and he was kind enough to offer to loan it to me. Thanks Jeff!

As you can see from the photo, it as a beautiful looking lock! All of Ranier's locks are individually milled out of brass, and the precision is superb. It is an extremely heavy puzzle, weighing in at over a pound (793g). It comes with a key.

When it arrived, I started working on it right away. As Jeff mentioned, the first move is pretty easy and I discovered it fairly quickly, since it is a standard trick. I also discovered a feature that I knew would be of importance, but was unable to proceed further.

I was stuck at this point for two weeks, playing around with it here and there for a half hour at a time. I emailed Jeff to let him know what I had tried and see if he could offer any small hints help me out. He provided a few bits of information about what not to do, which helped narrow down my search a bit.

This Sunday I headed up to my parents' house and brought a few other puzzles that they could check out, and figured I would bring this one along to see if I could make any progress.

Sure enough, while I was showing it to my mother, something new occurred to me! It was quite a relief to finally be making progress after 2 weeks of being stuck at the same spot. My hopes were high that I was moments away from figuring it out completely, however I immediately became stuck again. I learned slightly more about the feature that I knew would be of importance, but didn't actually discover the next step yet.

The next day, I finally figured out the next step! It was quite similar to what I had already tried, I just wasn't doing it quite right. I think that is my only criticism of this puzzle: this step is a bit harder to discover than it needs to be. There were a few things that could have been done to make it a bit easier to stumble upon, which wouldn't have decreased the difficulty or enjoyment of the puzzle much.

The next and final step only took me a minute or so to figure out, but it is quite cool. I didn't do it quite as intended, but it worked. The intended solution is even more elegant.

In total, I think I spent somewhere between 10 and 15 hours on this one. Puzzles like this take a ton of patience, since they give you so little to work with at first. Many hours of pushing, pulling, twisting, rattling, and whacking trying to figure out what is going on.

Jonas mentions in his blog post that this lock is as good if not better than Danlock (the gold standard for puzzle locks). I think I would agree that the craftsmanship is definitely superior: it is a much more complex mechanism that must have taken a lot of work to produce. As a puzzle, I still think I slightly prefer Danlock.

They both have some neat elements, but Danlock's simplicity gives it a bit of an edge in my mind. I could definitely see how some folks could tilt the other way if they prefer a more novel and clever mechanism. If the second move of the T4 was a bit easier to discover, I think it would have been a bit better.

Overall, an awesome puzzle that I would highly recommend if you have the budget for it. I am tempted, but I probably won't be buying one since they are so expensive and the International Puzzle Party is coming up. Woo hoo! This and other Popplocks can be purchased from Puzzle Master and Grand Illusions.

Thanks again to Jeff for making this review possible!

Twist the Night Away

Back when I was looking for interesting puzzles to build out of my LiveCubes, I stumbled across Twist the Night Away in this thread on the Puzzle World Forums. It is a 4x4x4 cube designed by Tom Jolly that requires 7 rotational moves to disassemble, which is quite remarkable.

Usually I'm not too keen on purchasing puzzles that I can build fairly easily with LiveCubes, but Eric Fuller was selling a wooden version for a very reasonable $40, so I decided to pick one up.

I loved Eric's description of this puzzle:

I was showing various puzzles to an IPP attendee when they skipped right over this one. I started to show it to them and they said "Everything interesting that can be done with 4x4 cubes has already been done". I laughed and showed them about half of the solution, at which time they cried "Stop - I'll take it!". This really is a fabulously interesting cube, and Tom really hit the ball out of the park with it. It's just a downright fun puzzle that still puts a smile on my face to solve.

Indeed, this really captures it perfectly: it is a remarkable design! In addition, Eric did an excellent job crafting it. The pieces fit together perfectly, and have a nice finish on them. It is made out of Carolina Mountain Ash and is 3 inches square. I really liked the way he constructed the pieces: it gives the puzzle a nice appearance on the outside when it is assembled.

Even though I had solved this one before with LiveCubes, it was a much better experience using actual wood since I didn't have to worry about the pieces coming apart. Not only is this a non-trivial puzzle to disassemble, I would say it is actually pretty tricky.

The first three pieces come out quite easily, but the remaining two pieces are trapped by a 4x4 'hoop' structure. Even knowing the solution, it still takes me a few minutes to remember how to do it. Also, check out Jonas's blog post on this one.

Putting it back together is even trickier. I brought it to a family event a few days ago and somebody was able to get it apart, but it took me about 15 minutes to get it back together again.

If you have a set of LiveCubes, head over to Puzzles Will Be Played to see what the pieces look like and give it a try. You won't be disappointed!

Oskar's Matchboxes

Oskar's Matchboxes is an interesting puzzle designed by Oskar van Deventer. It can actually be constructed by just gluing together matchboxes that are of the standard 3:2:1 proportions. I wasn't planning on buying this because I figured I could always make them out of matchboxes, but I never got around to it. Recently I decided to pick up a copy at The Games People Play in Harvard Square.

The version I got was made by Philos Games, a German company that produces as wide assortment of puzzles and games. Since it is mass produced, the price wasn't too bad at around $25. It has a nice appearance and even though the wood is unfinished, it has been sanded smooth. It is made out of Cassia Siamea and Beech, for a nice contrast. The Cassia Siamea has a nice grain pattern. The fit is a bit loose, but passable.

The puzzle itself consists of five pieces, each of which is made of a drawer attached to a lid. (In this version, the 'drawers' are actually blocks of wood.) The objective is to get all of the five matchboxes closed.

When I first tried this one, I got really lucky and was able to solve it in under 5 minutes. Pretty much the first thing I tried worked, which was quite surprising. I shrugged and figured it was an easy puzzle. A few days later I decided that I should probably try it again before I write my blog post, and sure enough it took me quite a bit longer, maybe 20 minutes or so. I must have just randomly positioned the first two pieces correctly on my first attempt or something.

During my second attempt, I discovered a second solution because I was attempting to solve it in a more systematic fashion. I prefer the appearance of the first solution I found to the second: the first one has boxes jutting out in all directions, while the second solution has one side that is flat.

I'd give this a 6/10 in terms of difficulty. It does take a fair amount of patience, but I think most folks will be able to get it if they keep at it for a little while. Overall, this is a solid puzzle, I'm quite pleased with it.

Trevor Wood, Tom Lensch, and Eric Fuller have each made runs of this design, and each one looks a bit different since the thickness of the wood can be chosen by the designer. Here's a photo of the version made by Tom out of super-thin 1/16" wood to replicate the look of real matchboxes. Very cool!

Interestingly, on Trevor Wood's site, he mentions that there are three possible solutions, but Eric and Tom both say that there are two. Trevor says that the third is only possible if the size and position of everything is just right. I haven't found a third solution on mine yet, but I'll keep at it!