Sharps and Flats: The Secrets of Cheating
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foreword to the online edition


I. introductory

II. common sharpers and their tricks

III. marked cards and the manner of their employment

IV. reflectors

V. holdouts

VI. manipulation

VII. collusion and conspiracy

VIII. the game of faro

IX. prepared cards

X. dice

XI. high ball poker

XII. roulette and allied games

XIII. sporting houses

XIV. sharps and flats









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The Coin Toss

It would be safe to assume that the coin toss is probably one of the oldest gambling games. The game requires a simple prop that also happens to be the object of the game, i.e. money, or more specifically a coin (please note that paper money was only introduced later in history).

The coin toss is a game that is likely to have evolved spontaneously, in various parts of the world independently from each other. Any coin, after all, has two sides and a coin toss is nothing but a simple guessing game.

If we assume that the legitimate game evolved spontaneously, we can further assume that the crooked versions of the game also evolved spontaneously. When cheating (at any gambling game in general) the objective is always the same: to win money. This objective can be accomplished in various ways. In the case of simple gambling games, such as a coin toss, the most logical approach is to influence the outcome of a future event. In more complex gambling games there may be other approaches, such as manipulating the amount wagered, gaining information (such as using marked cards), wagering after the outcome is already known, etc...

Pursuing our investigations, then, let us suppose that we now approach one of the spots where winners and losers, sharps and flats, meet on the common ground of applying meat and drink to the refreshment of body and soul. Here, if we are favored, we may chance to meet with a little entertainment intellectual and instructive provided by the spectacle of three persons who are engaged in the scientific recreation of spinning coins upon some convenient corner of table or buffet. Needless to say, they are two 'sharps' and a 'flat,' and their little game is 'odd man.'

The game is simple, but financially there is a good deal in it. It is played in this way. Three coins being spun on edge upon a table, it is obvious that either all three will fall with the same side up in which case the spin must be repeated or, two will fall one way and one the other. The owner of the latter coin is the 'odd man.' There are two systems of playing. Either the odd man is out that is to say, he stands aside, whilst the other two spin for 'head' or 'woman' or the odd man pays. In either case, the loser pays the other two. If fairly played, of course the chances are equal for all three players. But, alas! even this apparently innocent game is capable of sophistication.

The method of cheating will be seen at a glance on referring to fig. 2.

A coin which has been slightly beveled to one side will bear a superficial examination without creating suspicion as to its genuineness. If it has a milled edge, it must necessarily be re-milled. Such a coin, when spun on edge, will always tend to fall in one direction. The beveling, as shown in the figure, is exaggerated, for distinctness' sake; in practice, the angle is very slight.

Two 'sportsmen,' each provided with coins of this description, meet with a 'mug' and propose spinning for liquid refreshment. If they are pretty sure of their man they may possibly allow him to win. Afterwards, however, they lead him on to spin for higher stakes, and then he invariably loses.


Beveled Coins

FIG. 2 -- Beveled Coins

If the game is 'odd man pays,' they spin with coins which will fall alike; simultaneously changing their coins from time to time, so that they do not always bring them same side up. This being so, all three coins must either fall alike, or else the dupe will be the odd man. Then he pays each of his companions the amount of the stakes. Thus, the chances are dead against the dupe, for his opponents cannot possibly lose.

When the game is 'odd man out,' the winnings are not made so rapidly; but at the same time they are quite as certain, and the proceedings are not so liable to create suspicion. In this case, the sharps spin, with coins which will fall in different directions, and consequently the dupe is never the odd man. His coin is bound to fall the same way as one of the others; so he has to spin again with one or other of the 'rooks.' If the second spin is 'head wins,' the sharp will use a coin which falls 'head.' Here, again, the coins must either fall alike, and the spin be repeated, or the dupe must lose.

To disarm suspicion, however, the second spin may occasionally be a fair one; his opponent using a 'square' coin. Even then, the chances are two to one against him. Supposing the stakes are a sovereign, the loser has to pay the two winners a sovereign each; and therefore if the dupe loses he has to pay two sovereigns, whilst, if he wins, he receives only one. So much, then, for 'odd man.'

It is very usual for gamblers to keep raising the stakes, when losing. This is done in an attempt to recuperate the previous loses, and winning a small amount on top. Since this is a commonly accepted behavior amongst gamblers, this psychology can be used (and often is) against unsuspecting dupes.

In the case of a coin toss, the sharpers would at first use a coin that would make them lose. They would insist on doubling their bets and the sucker, confident that he is on a lucky streak, would gladly accept. The money would keep accumulating in front of the sucker and then he would lose it all on one spin. From that point on the sucker would attempt to recuperate "his" money. However, although he did lose a pile of money on a single coin toss, in reality he only lost the small amount that he had originally wagered. If the sucker were to walk away at this time, he would only have suffered a small loss. But the psychological effect, in the suckers mind, is that he could have walked away with a nice bundle. So, in order to recuperate he offers to double his bet. The sharpers gladly accept, as this time around, the sucker is about to lose more than the original minimum bet.

If the sucker loses on that spin (which he most certainly does, unless the sharpers are playing some other reverse psychology, for whatever reason) he will most likely want to double his bet (or at least place a large one) on the next spin. But from that point on, the sucker just never seems to be able to win again.


The coin gaff that Maskelyne described is a beveled coin. Another gaff that is commonly used for cheating at Odd Man Out is a double-sided coin. The double-sided coin is the gaff that would be used when the coin is tossed up into the air, instead of spun on the table. Of course, since a double-sided coin is a pretty obvious gaff, it would never be used in the spinning scenario, as it is too likely to be discovered. Also, when expert sharpers are at work, the sucker has no chance at discovering a double-sided coin, as the coins a constantly switched in and out of play. So, if a sucker is ever given the opportunity to examine the gaff, you can bet the house that he's not looking at the same coin.

The double-sided coin offers a 100% sure outcome. In other words, if the coin is double-headed, there is no way that it will ever land on tails. At first glance, the beveled coin seems to be a percentage gaff; meaning that it is not guaranteed to land on the desired side, every time. But in actuality, the beveled coin is not a percentage gaff at all. If the coin is beveled to lan on tails, it cannot possibly land on the other side, due to the fact that the center of gravity always pulls the coin down the same side. Even a slight bevel will guarantee a 100% predictable outcome.


It should also be noted that professional sharpers do not necessarily have to emplay a gaffed coin, to do a coin toss scam. There are several manipulation tricks that can be employed to gan an advantage, without the use of a gaff.

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