Samuel Loyd (January 31, 1841–April 10, 1911) was an American puzzle author and recreational mathematician.

Loyd claimed from 1891 until his death in 1911 that he invented the fifteen puzzle but he had nothing to do with the invention or popularity of the puzzle. As a chess composer, he authored a number of chess problems, often with witty themes. At his peak, Loyd was one of the best chess players in the U.S., and was ranked 15th in the world, according to Chessmetrics.

An enthusiast of Tangram puzzles, Loyd published a book of seven hundred unique Tangram designs and a fanciful history of the origin of the Tangram.

Following his death, his book Cyclopedia of Puzzles was published (1914).

Excelsior problem

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''Main article: Excelsior

One of his best known chess problems is the following, called "Excelsior" by Loyd after the poem by Henry Wadsworth Longfellow. White is to move and checkmate black in five moves against any defense:

Loyd bet a friend that he could not pick a piece that didn't give mate in the main line, and when it was published in 1861 it was with the stipulation that white mates with "the least likely piece or pawn".

Trick Donkeys problem

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Another significant problem is called the "Trick Donkeys" problem. In the problem, the reader must cut the drawing along the dotted lines and the rearrange the three pieces so that the riders appear to be riding the donkeys. It is solved by an optical illusion.

Books

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• Sam Loyd's Book of Tangram Puzzles (ISBN 0486220117): by Sam Loyd
• Mathematical Puzzles of Sam Loyd (ISBN 0486204987): selected and edited by Martin Gardner
• More Mathematical Puzzles of Sam Loyd (ISBN 0486207099): selected and edited by Martin Gardner
• The Puzzle King: Sam Loyd's Chess Problems and Selected Mathematical Puzzles (ISBN 1886846057): edited by Sid Pickard
• The 15 Puzzle (ISBN 1890980153): by Jerry Slocum and Dic Sonneveld

See also

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• Henry Dudeney

External links

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• Biography from the School of Mathematics and Statistics website at the University of St Andrews
• The Sam Loyd Cyclopedia of Puzzles - The complete 1914 book by Sam Loyd (public domain) scanned
• Cyclopedia of Puzzles by Sam Loyd - All puzzles from the book as a web site
• Farmer and Wife to Catch Rooster and Hen - interactive Sam Loyd's puzzle
• Chessmetrics entry for Loyd

Puzzle designers | 1841 births | 1911 deaths | Chess problemists

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