Coin-matching game

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A coin-matching game (also a coin smack [1] or smack game [2] ) is a confidence trick in which two con artists set up one victim.

The first con artist strikes up a conversation with the victim, usually while waiting somewhere. The con artist suggests matching pennies (or other coins) to pass the time. The second con artist arrives and joins in, but soon leaves for a moment. The first con artist then suggests cheating. The victim, thinking they are going to scam the second con artist, agrees to match coins each time.

When the second con artist returns and begins losing, he accuses the two of cheating and threatens to call the police. The first con artist offers a sizable sum of hush money, and the victim contributes something too. After the victim leaves, the two con artists split up the money extorted from the victim. [3]

In game theory the term refers to a zero-sum two-person game of imperfect information (not involving a third player or collusion); [4] [5] [6] other variations on the name are "matching coins" or "matching pennies". [7] [8]

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Entropy (information theory) Average rate at which information is produced by a stochastic source of data

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Nim

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Prime number Positive integer with exactly two divisors, 1 and itself

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Confidence trick Attempt to defraud a person or group after first gaining their confidence

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Matching pennies is the name for a simple game used in game theory. It is played between two players, Even and Odd. Each player has a penny and must secretly turn the penny to heads or tails. The players then reveal their choices simultaneously. If the pennies match, then Even keeps both pennies, so wins one from Odd. If the pennies do not match Odd keeps both pennies, so receives one from Even.

Pigeon drop Confidence trick

Pigeon drop is a confidence trick in which a mark or "pigeon" is persuaded to give up a sum of money in order to secure the rights to a larger sum of money, or more valuable object.

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Odds and evens is a simple game of chance and hand game, involving two people simultaneously revealing a number of fingers and winning or losing depending on whether they are odd or even, or alternatively involving one person taking picking up coins or other small objects and hiding them in their closed hand, while another player guesses whether they have an odd or even number. The game may be used to make a decision or played for fun.

Three-card Monte

Three-card Monte – also known as Find the Lady and Three-card Trick – is a confidence game in which the victims, or "marks", are tricked into betting a sum of money, on the assumption that they can find the "money card" among three face-down playing cards. It is very similar to the shell game except that cards are used instead of shells.

Fair coin

In probability theory and statistics, a sequence of independent Bernoulli trials with probability 1/2 of success on each trial is metaphorically called a fair coin. One for which the probability is not 1/2 is called a biased or unfair coin. In theoretical studies, the assumption that a coin is fair is often made by referring to an ideal coin.

In game theory, an epsilon-equilibrium, or near-Nash equilibrium, is a strategy profile that approximately satisfies the condition of Nash equilibrium. In a Nash equilibrium, no player has an incentive to change his behavior. In an approximate Nash equilibrium, this requirement is weakened to allow the possibility that a player may have a small incentive to do something different. This may still be considered an adequate solution concept, assuming for example status quo bias. This solution concept may be preferred to Nash equilibrium due to being easier to compute, or alternatively due to the possibility that in games of more than 2 players, the probabilities involved in an exact Nash equilibrium need not be rational numbers.

Penneys game

Penney's game, named after its inventor Walter Penney, is a binary (head/tail) sequence generating game between two players. Player A selects a sequence of heads and tails, and shows this sequence to player B. Player B then selects another sequence of heads and tails of the same length. Subsequently, a fair coin is tossed until either player A's or player B's sequence appears as a consecutive subsequence of the coin toss outcomes. The player whose sequence appears first wins.

Geometry Branch of mathematics

Geometry is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space that are related with distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is called a geometer.

References

  1. Porter, Thomas J. Jr. (November 28, 1969). Con Artists Show Diversified Skills. Pittsburgh Post-Gazette
  2. Associated Press (January 11, 1963). 3 sentenced; they picked wrong man. The Spokesman-Review
  3. Staff report (November 9, 1913). Coin matchers of Times Square are doing rushing business; Detective Says He Knows No Less than 100 Professionals in That Line, Who Feel Safe Because Few Ever Get "Sent Up." The New York Times
  4. Robert Clarke James; Glenn James (1992). Mathematics dictionary. Springer. p. 180. ISBN   978-0-412-99041-0.
  5. Soo Tang Tan (2005). Finite mathematics for the managerial, life, and social sciences. Cengage Learning. p. 543. ISBN   978-0-534-49214-4.
  6. Herman Chernoff; Lincoln E. Moses (1959). Elementary decision theory. Courier Dover Publications. p. 346. ISBN   978-0-486-65218-4.
  7. Peter Morris (1994). Introduction to game theory. Springer. p. 11. ISBN   978-0-387-94284-1.
  8. Julio González-Díaz; Ignacio García-Jurado; M. Gloria Fiestras-Janeiro (2010). An Introductory Course on Mathematical Game Theory. AMS Bookstore. p. 29. ISBN   978-0-8218-5151-7.