a.k.a.L'Ane Rouge, Which Way Out, Psychotease,

Escaping Jail, Cao Cao Escape, Klotski

Patented in England by J. H. Fleming 1932,

this one is "Which Way Out" by T.C. Timber Brain Twisters circa 1995,

in a box made by J. A. Storer 2007.

(maple, tray and 10 pieces, 2x2 is painted red, 3.75 x 3.5 x 0.9 inches;

box is resized cigar box with brass hardware, 4.75 x 4.75 x 1.75 inches,

lid diagram also showsSimple Traffic Jam,Century, andSuper Century)

Hordern's bookcredits the Red Donkey as the third most sold sliding block puzzle (after theFifteenpuzzle andDad's Puzzler). It is shown in the 1996 design patent of Mendelsohn and the 200 patent ofL. Aryan. The goal is to slide the 2x2 piece (without picking pieces up) to the bottom center so that it can drop out through the opening (we will not charge an extra move for falling through the opening even if the final move of the 2x2 piece is in the horizontal direction). This puzzle is likeSimple Traffic Jam, with the 1x2 piece move above the 1x1's. There are a number of starting position variations, the leftmost being the original FrenchL'Ane Rouge:

The September 2000 patent of L. A. Aryan describes the same puzzle as the Red Donkey puzzle. Figure 1 shows the puzzle (the box lid is corrected in a revised Figure 1 at the end of the patent). The claims describe a ten piece sliding piece puzzle with a hinged lid. Some study might be required to determine exactly what is new about this patent. Figure 4 presents a (not minimal) solution of 22 positions that require multiple moves (a total of 99 straight-line moves):

Here is the solution idea that came with Which Way Out. Many of these positions represent several moves (a total of 118 moves straight-line moves):

Here is a solution of 90 straight-line moves for Version A; it can be converted to 81 rectilinear moves by combining steps 10/11, 14/15, 24/25, 39/40, 47/48, 52/53, 55/56, 79/80, and 88/89:

The solution presented on the preceding page for Version A (and also the 81 rectilinear moves solution that is presented inHordern's book- Puzzle C27d) is minimal and reaches exactly the same position at Step 4 as does a minimal 81 rectilinear moves solution (90 straight-line moves) for the Version B and C start positions (and so step 4 onward can be used for all three puzzles):

The Winning Ways book shows the Version D start position. Step 6 of a minimal solution for this variation is exactly the same as Step 4 above, and so this variation has a minimal solution (for both straight-line and rectilinear moves) of 2 moves longer than Versions A, B, and C (pieces 1, 2, 3, 4 must be renamed to 3, 1, 2, 4):

Simple Traffic Jam

Shafir Games 1981;

minimal solution of 64 rectilinear moves.

Century

Designed by J. H. Conway 1975;

minimal solution of 99 rectilinear moves.

Super Century

Designed by Gil Dogon 2004;

minimal solution of 138 rectilinear moves.

Psychotease, copyright 1969.

(cardboard box and 10 wood pieces, 9 x 11 x 1.5 inches)

Escaping Jail, copyright University Games Co. 1993, made by Raintree Puzzles.

(wood box and 10 wood pieces, 4.4 x 3.25 x 1.2 inches)

Cao Cao Escape, LEO Marketing, 1995

(wood box and 10 wood pieces, 3.8 x 3.125 x 3/4 inches)

Further Reading

Wikipedia Klotski Page, from: http://en.wikipedia.org/wiki/Klotski

Pegg's Page, from: http://www.maa.org/editorial/mathgames/mathgames_12_13_04.html

Baxter's Page,, from: http://www.puzzleworld.org/SlidingBlockPuzzles/4x5.htm

Aryan Patent, from: www.uspto.gov - patent no. 6,116,600

Armendariz Design Patent, from: www.uspto.gov - patent no. 367,502

Mendelsohn Design Patent, from: www.uspto.gov - patent no. 388,840