Are There Any Good 2-Piece Puzzles Which Can Baffle?

 by Serhiy Grabarchuk, Jr.
When it comes to mechanical puzzles it always comes to pieces. A mechanical puzzle can hardly be imagined as an entity not consisting of pieces. What really differs and matters is the objective. In some puzzles the pieces are put together, in others – taken apart, in some – slid around, in others – removed or interchanged, etc.

Often, though not necessarily in all cases, the more the pieces, the harder the puzzle can be. In some puzzles the number of pieces can reach hundreds or even thousands (that is not counting some jigsaw puzzles alone). Not discussing how fun such puzzles can be, they can definitely baffle the solver. But more interesting is to take a look at the opposite end of the set. Since a set consists of at least two pieces (if not count such a particular case as a 1-piece folding puzzle) a key question is if there are any 2-piece puzzles which can really baffle? Fortunately, the answer is “Yes!”

Several preconditions had been considered while selecting the puzzles for this review.
1. The 2-piece puzzles have not to be trivial.
2. The pieces for these puzzles can be compound pieces, not one-block pieces. But if such a piece is broken into the smaller blocks the idea of the puzzle is totally lost.
3. Very specific cases of the 2-piece puzzles, for example, such as mazes (one piece can be the board and another one – the moving token) haven’t been considered for this review.
 2-Piece Pyramid: fit two pieces to get a regular tetrahedron. Image from Source
It seems the 2-Piece Pyramid puzzle is still the most familiar and recognizable among all 2-piece puzzles. To many of us it was presented in our childhood. The impression lasts for a lifetime and is strongly associated with both simplicity and ingenuity. One of those brighter “easy looking-tricky solving” puzzles. Moreover it is one of the rare 2-piece puzzles with both pieces identical. Despite this fact even experienced adults can have substantial difficulties while finding a solution. Guess, the reason is the puzzle deals heavily with the 3D imagination. And while many of us can imagine the shape of a pyramid (a regular tetrahedron), the idea it can be broken into two identical parts is not that easily perceived at all.

The Puzzle & Craft Factory sells a handmade wooden version of the 2 Piece Pyramid Puzzle.

Several years ago a leading puzzle company ThinkFun has come with a plastic version of the puzzle – Aha! Pyramid Twins (buy at Amazon) as a part of their bigger set of eight world-famous ingenious puzzles – Aha! Brainteaser Classics (buy at Amazon).
 Nails: separate two bended nails. Image from Source Cast DEVIL: separate two pieces. Image from Source
Quite a good number, if not to say significant number, of the 2-piece puzzles can be found among wire puzzles. Not all of them can be considered very intriguing and many of them can happen to be different variations of the same principle, but there are definitely some of them worth to pay closer attention to. Dick Hess has made a wonderful job publishing Compendium of Over 10500 Wire Puzzles (7th Edition, December 2003) and many 2-piece wire puzzles can be found directly in his book. Probably the most interesting among the 2-piece wire puzzles remains a couple of the so-called “hard wire puzzles” – the classic Nails and some of their modifications; and Sao Paulo puzzle. They both are example of puzzles consisting of two identical pieces. In each of them the objective is to take apart the two pieces. An inexpensive version of the Nails produced by Parlor Puzzles can be bought at Amazon. By the way Parlor Puzzles produces a collection of 2-piece wire puzzles (buy at Amazon). ThinkFun has been also producing a version of Sao Paulo puzzle as a cast replica – Twin Tangle (buy at Amazon). Another cast metal version of this puzzle – Cast DEVIL – is produced by Hanayama and can be bought at Torito online store.
One more very interesting classic 2-piece design is the Hedgehog in a Cage puzzle. It consists of two different pieces – one is a cylindrical cage and another is usually a ball with several rods protruding from it (the “hedgehog”). The ball is placed inside the cage and the objective is to get the ball out of it. There are a number of puzzle’s versions produced in plastic, wood or metal. A handmade wooden version of the puzzle can be bought from Wooden Toys Shop. A metal modification of the Hedgehog in a Cage from Czech Professor Bakalar is manufactured by Hanayama as Cast CAGE (a part of the Cast Puzzle series – please see below) and can be bought at Torito online store.

 Wooden handmade version of the Hedgehog in a Cage - from Wooden Toys Shop. Cast CAGE - a metal variation on Hedgehog in a Cage puzzle. Manufactured by Hanayama. Can be bought at Torito website. Image from Source Image from Source
 Moby Maze: probably the first maze built on a Moebius Strip. Image from Source
Coming to contemporary 2-piece puzzles it is worth to mention a number of designs from a prolific Dutch puzzle designer Oskar van Deventer. Mostly these are Oskar’s maze-based brand concepts - Basketball, Bronco, Moby Maze, Rotten Apple, Sunflower, Tube Maze, etc.. These and some other his designs can be bought from George Miller’s Puzzle Palace (simply find them in the inventory list based on the title or the author's name).

Several more amazing 2-piece designs came recently from a leading Japanese puzzle designer Iwahiro. First of all this is his clever Caged Pyramid puzzle – remove pyramid from the cage. Can be bought at Puzzlein (Japanese website). No less tricky is his Dinghy puzzle - remove the chain from the wire part and then return it to the starting position again. And then there is Twinquint - a puzzle where the goal is to create a pyramid with just two pieces each of which consists of five balls jointed together. It can be bought at Torito (the page with the puzzle is in Japanese).
 Caged Pyramid - remove pyramid from the cage.
 Dinghy - remove the chain from the wire part.
 Twinquint - create the pyramid with two 5-ball pieces.
Image from Source Image from Source Images from Source

On top of all described above there exists a real “treasure chest” of 2-piece puzzles that one can ever think of. Hanayama, a Japanese toy company, produces a special Cast Puzzle series containing precious gems by puzzle designers from different parts of the world. The geography is really widespread – Japanese Nob Yoshigahara and Akio Yamamoto, Dutch Oskar van Deventer, Ukrainian Serhiy Grabarchuk, Finnish Vesa Timonen and others. Amazingly, but among current 40+ beautifully cast metal puzzles in the series 2/3 are the 2-piece puzzles! The entire series can be viewed here, while the puzzles can be bought at Torito website.
 View the entire Cast Puzzle series here: Buy the puzzles of the series from Torito.
This year’s gem of the Cast Puzzle series is undoubtedly Cast LOOP from Finnish designer Vesa Timonen. The puzzle, “born in plastic to become a metal classic” (read the history of puzzle at George Miller’s site – simply click the “Cast Loop” on the inventory page) has been presented at the 27th International Puzzle Party, August 2007, Australia. The two identical pieces (differ only in the poles of two tiny magnets) which have to be fitted together to create a complete ring had become an instant hit and won the top Puzzlers' Award at Nob Yoshigahara Puzzle Design Competition 2007. Hanayama indicates the puzzle’s difficulty level as “Easy” (one point from six possible), but it seems the puzzle is in fact a little bit harder and the story reminds the one with the 2-Piece Pyramid. Don’t be upset if it takes you not a minute, but maybe five, ten, half an hour or even an hour to solve the puzzle. Whatever it takes, be sure getting the complete ring on your palm will be a valuable reward for all your attempts. The puzzle is wonderfully designed and manufactured and it brings a lot of joy. It is strongly recommended as an addition to any puzzle collection, and it constitutes an excellent gift or souvenir to enrich your pastime and parties.
 Cast LOOP by Vesa Timonen - based on an original puzzle ring he created for his girlfriend. Fit two pieces together to create a complete ring. The puzzle can be bought from Torito website. Images from Source
Once again, the puzzles reviewed here are not the ultimate list of the 2-piece concepts. If you know of more non-trivial 2-piece puzzles which really can baffle and are worth to pay attention to, please, drop us a line.

Posted: November 11, 2007   Last Updated: December 1, 2007