Eller Puzzle

Requires a Wolfram Notebook System
Interact on desktop, mobile and cloud with the free Wolfram Player or other Wolfram Language products.
Recreate the original setup using only knight hops.
[more]
Contributed by: Karl Scherer (March 2011)
Open content licensed under CC BY-NC-SA
Snapshots
Details
The "set up" Checkbox
Click "set up" to create your own setup or amend a given setup. Clicking a position repeatedly will cycle through the tokens. Once you are happy with your setup, click the "set up" checkbox again.
Please note that only one position should be unoccupied in any setup!
How to Build Your Own Real Game
The Eller puzzle makes a nice solitaire game which you can easily manufacture yourself.
Here are the details of the author's board:
Take a square board of thick acrylic about 27 cm long; drill 25 holes of 25 mm diameter and use large marbles or glass balls (30 mm diameter) as tokens. Finally, glue a 27×27 piece of thin white acrylic underneath the clear board to enhance the look.
Once you have played this hands-on version of Eller, it becomes clear why there is an empty position on the board (instead of all positions being filled and the moves consisting of swapping two tokens): it is much easier to only move one ball at a time, especially for children.
History
The Eller Puzzle was first published by the same author as a Zillions game.
Permanent Citation
"Eller Puzzle"
http://demonstrations.wolfram.com/EllerPuzzle/
Wolfram Demonstrations Project
Published: March 7 2011