Sam Loyd

Who was Sam Loyd, you ask? Erno Rubik would tell you there would be no Rubiks cube without Sam Loyd! Loyd was a world renowned American puzzle creator and mathematician that inspired millions.

Sam Loyd (1841-1911) was born in Philadelphia, Pennsylvania to a well off estate agent. Sam was the youngest of nine children and spent most of his childhood in New York where he became fascinated with the game of chess. From very early on Sam became well known for his ability to solve very complicated chess problems which eventually landed him a job as a problem editor for Chess Monthly Magazine. After some schooling to become a mechanical engineer he visualized an opportunity to make a living off of his chess problems and logic puzzles.

By 1870 Loyd had become more interested in composing mathematical puzzles than chess problems. He had composed a famous problem consisting of three cards, two with the picture of a horse and the third with a picture of two jockeys. The puzzle was to rearrange the pieces so that the jockeys were riding the horses. He sold it to the showman P T Barnum and it became famous as P T Barnum's Trick Donkey. He published many books in his time that outlined many of these famous puzzles.

Loyd's most famous puzzle was the 15 Puzzle (Puzzle of 15) which he produced in 1878. The 15 puzzle was a sliding tile puzzle using a 4x4 grid. The goal of the game was to rearrange the numerical tiles into ascending order by sliding one tile at a time. Loyd wrote about the puzzle in Sam Loyd's Cyclopaedia of 5000 Puzzles, Tricks and Conundrums which was published in 1914 after his death. This puzzle gained an extreme amount of exposure due to a contest Loyd had started. Loyd saw that it was virtually impossible to solve his puzzle if the fifteen blocks were arranged in the square box in rectangular order, but with the 14 and 15 reversed as shown in the following image.

Loyd offered a a prize of $1000 for the first correct solution to the problem. However, that prize still goes unclaimed even though many people claim to have solved it. People became infatuated with the puzzle and many 'tales' arose of people trying to solve it for days at a time. Many said they could solve it but failed to reconstruct it in front of Loyd. The mysterious feature of the puzzle is that none seemed able to remember the sequence of moves they took to result in completion. According to Loyd the puzzle is mathematically impossible to solve and felt his money was safe. A slide puzzle like the puzzle of 15 with square pieces can only be solved when the number of exchanges necessary to solve the puzzle is even. The 14-15 puzzle attracted world wide attention that can only be compared with the Rubik's Cube that conquered the world 100 years later. Erno Rubik drew his inspiration from this slide puzzle when he designed his famous cube which can be seen as a 3 dimensional version of a slide puzzle. Read more about Loyd's influence on Erno Rubik.

Loyd not only conceived many logic puzzles, he also was a skilled entertainer and gave many performances of ticks and ventriloquist acts. Loyd produced over 10,000 puzzles in his lifetime, many involving sophisticated mathematical ideas to solve problems.

Moon Valley challenges PDA users to give the 14-15 puzzle a try. Now available for free download is the Puzzle of 15 for Pocket PC. You can try Loyd's famous 'unsolvable' 14-15 puzzle or test your problem solving skills on easier solvable tile arrangements using numbers, letters, or pictures.

Download Puzzle of 15