Pierre-sheet-scissors

Pierre-sheet-scissors is a Jeu children, also called paper-stone-scissors or chifoumi in France, rock-paper-scissors with the Quebec, stone-paper-scissors in France and Belgium, sheet-stone-scissors in Suisse. There exist many regional alternatives.

The two players choose simultaneously one of the three blows by symbolizing it with the hand: In a general way, the stone beats the scissors (by blunting them), the scissors beat the sheet (while cutting it), the sheet beats the stone (by wrapping it). Thus each blow beats another blow, fact tie against the second (its counterpart) and is beaten by the third.

History

Just like the Play of Go and the Mahjong, stone-sheet-scissors was invented in China. According to a book named Wǔzázǔ (五雜俎 or 五雜組) written by Xiè Zhàozhì (謝肇淛) towards the end of the period Ming, the lords of the Dynastie Han played play called shǒushìlìng (手勢令) which is regarded as being stone-sheet-scissors.

There is no trace of stone-sheet-scissors in Occident before there are direct contacts with Asia. The Western authors of the end of the 19th century only mentioned it like an Asian play. The Chinese and the Korea NS use the fabric with the stone and the scissors , whereas the Japanese have it famous sheet . This indicates that this play arrived to Occident in contact with the Japan.

Strategy or chance?

The solitary alternative consisting in playing against a machine using the optimal strategy constitutes a game of pure chance. One cannot thus, strictly speaking, classify stone-sheet-scissors like game of reasoned chance. This category of plays rather relating to the plays with noncomplete information, founded on the probabilities, where tangible elements make it possible to support such behavior instead of another.

In the alternative with troix choice, the optimal strategy, within the meaning of the Game theory, consists in choosing the blows in a random way, in an equiprobable way. However, it is only the strategy guaranteeing that there does not exist strategy of the adversary enabling him to gain with a Probabilité strictly higher than 1/2. Vis-a-vis an adversary practitioner a sub-optimal strategy, it is possible to find strategies gaining, based on the knowledge of the adversary.

Many experiments suggest that it is quasi-impossible with human to generate a random sequence without the assistance of a random generator (die, coin,…) or pseudo-random (computer, list of the decimals of π,…). On the basis of this report, players try to include/understand the sequences of their human adversary to be opposed to it. That amounts playing in a “psychological” way, as with the Poker, for example. But by choosing this way of playing, if one is almost certain to move away from the 50% of chance gains, one is not absolutely certain to move away some in the good sense. In addition, the best method to be opposed to an adversary which tries to include/understand its sequences consists in playing indeed most randomly possible, which is not “anti-play” since it is the best way of posing problems with the adversary.

Pseudo-federations

Many Web sites affirm to organize events imitating the great sporting events without it being really possible to consider their width real. Two French sites exist, that of the Championship of the world of sheet stone scissors (FCC) and that of the Swiss Federation of RPS (of English Rock Paper Scissors).

The only organization whose real existence is established is the international company of the RPS ( World RPS society ) based with Toronto which says to count approximately 350 members. It organizes an expensive tournament and richly equipped, that it entitles “championship of the world”. In 2003, this tournament joined together several hundreds of participants hoping to touch the first prize like some spectators of the Toronto-native agglomeration. The tournament drew the attention of the media. It is however enough to consult the site of this organization to understand that it is about a parody of sporting federation.

Regional alternatives

In some of these alternatives, one sees appearing new symbols:

the well beats the stone and the scissors (by making them fall at the bottom) and is beaten by the sheet (which recovers it). In this alternative, the well and the sheet carry it in two cases out of four while the stone and the scissors only once on four. However, the scissors are the only ones to carry it on the sheet ; and like in addition, between the stone and the well , one notes that each of both has the same results against sheet and scissors , but that well overrides stone , the balance of Nash of the play consists in never not playing stone , and making as if the play were well-sheet-scissors .

Internal bonds

Paradox of Condorcet

External bonds

Interplanetary Championship of Sheet Stone /prochain Scissors on September 7th, 2008/Lausanne/Suisse
World RPS Society
Couverture presses championships of the world of Swiss RPS
Sporting Fédération of Sheet Stone Scissors
Swiss Fédération of RPS

Simple: Rock'n'roll, paper, scissors Zh-yue: 猜包剪揼

Random links: