1. Field of the Invention
The present invention relates to card sorting devices, and more particularly, to automatic card sorting devices.
2. Statement of the Problem
Card games requiring a plurality of game cards are quite common. Card games generally require that the plurality of cards be reordered (shuffled) to provide a random distribution so that no advantage is given to any participant in the play of the game based on the likelihood of a particular card being at or near a particular location. To achieve this random distribution the cards are usually shuffled several times by a person acting as a dealer. The processes typically employed by dealers result in reordering the game cards in a deck that approaches but does not achieve randomness. Consequently certain skilled individuals are able to locate or nearly locate cards critical to the play with a degree of accuracy sufficient to gain a sizable edge in the play of the game. This process has been well documented for the game of BLACKJACK and is normally referred to as "shuffle-tracking".
Recently, mechanical shufflers have been designed to perform the shuffling, and some of these are controlled by computer components to assist in the physical movements involved. However, all current methods involve a mechanical shuffle mimicking the process used by the human dealer, and like the shuffle produced by a human dealer, such methods approach but do not achieve randomness. Many of these machines have a tendency to move a number of cards at a time so that it is possible that several adjacent cards will remain together before and after the shuffle. In any event, shuffles produced by a human or a mechanical device are difficult to test for randomness in the real environment of a gaming table.
Additionally, it is desirable to know that the plurality of cards is intact in terms of card suit information, the number of cards of a specific rank, as well as total number of cards in the plurality. This is valuable in that the introduction of additional cards or the removal of certain cards can have a dramatic effect on the probabilities involved in the play of the game.
All shuffling techniques produce a certain amount of stress or friction to the card surfaces thus affecting the life of the cards. Therefore, it is desirable to achieve the shuffle with as little card movement as possible. Mechanical designs tend to require repeated shuffles (or "riffles") to achieve randomness.
It is further desirable that a card sorting device be used to return the plurality of cards to the "as new" sequence (referred to herein as the "new" sequence) for storage, sale, or reintroduction to the game at a later time. In BLACKJACK it is common to frequently introduce new decks of cards frequently. When removed from the tables, these decks are sorted back into new sequence by hand, stored and sold in gift ships, vending machines located in the casino or to various wholesalers. After sorting, these cards are usually drilled, dog-eared, or otherwise altered so as to distinguish these from new decks. It is estimated that some 10,000 BLACKJACK tables in America use over 30 million decks each year, most being sorted back to original ("new") order by hand.
Furthermore, several games require a specific sequence that is not random, but is different than the sequence of a typical "new" deck. For instance, in poker, the deck is presented to the table for play by spreading the cards on the table. The suit order required in poker is spades, hearts, clubs, and diamonds. It is common to use cards that are alternatively presented to the table for play, removed and resorted to this sequence, and then used in play again. Such a sequence, which is not random but dictated by the play of the game, is referred to herein as a "game play" sequence. The constant sorting is currently accomplished by various employees as a secondary duty.
It is also desirable to verify that a winning hand indeed came from the dealer's deck and did not come from another deck. Many games offer large prizes for certain infrequent card combinations, such as Caribbean Stud in which the jackpots are often over $100,000. The added security of being able to verify a hand by checking the card sequence of the card deck is of importance to casinos offering such games in order verify winning hands.
It would be desirable to have a single device to solve the above stated problems that is compact, adaptable to mounting on a gaming table, and that requires little operator skill or training. Such a device should shield the sorting process from view of the players, and should be free of annoying sounds or vibrations. Also, the device should be fast, accomplishing a complete sort in less than one minute. The prior art is devoid of any single device or process capable of sorting into a random, new, or game play predetermined sequence and having these characteristics.
3. Solution to the Problem
The present invention satisfies the aforementioned needs by providing an automatic card sorter that either provides a shuffled stack with a predetermined random sequence or sorts a stack into a new, game play, or other user-defined predetermined sequence. All (random, new, game play, or other user-defined) sequences are referred to herein as "predetermined" because the sequence of the final sorted deck is determined before any card is moved. Although the present invention can be used to sort a large variety of cards, the present discussion, for illustration purposes, will discuss the invention in the context of a stack of one or more standard decks of game cards, each card having a rank and suit printed on its face.
The automatic card sorter of the present invention includes at least one card reader for reading the characters on the face of a game card. From the input from the card reader, the controller, typically a microprocessor in conjunction with appropriate software and hardware, determines the rank and suit of the card. The controller also has sufficient memory to store a variety of information. The card reader, in an alternative embodiment, can also read identification codes (other than rank and suit information).
Having been given a stack to be sorted through an appropriate user interface, the controller provides a predetermined sequence for the cards. This predetermined sequence can be random as provided by a random number generator, the same sequence as a new deck (the "new" sequence), or game play (such as required by poker described above) predetermined sequence. An operator chooses the desired predetermined sequence, either a random sequence, "new" sequence, or game play sequence. Additional user-defined predetermined sequences could be provided for. Once the choice is made, the controller provides the predetermined sequence by retrieving the appropriate sequence from either a random number generator (when the choice is "shuffle") or memory.
The automatic sorter also includes a moveable tray having at least as many slots as cards in the stack. In the preferred embodiment, the first slot of the tray will receive the card having the value of the first position in the predetermined sequence. Hence, once the predetermined sequence is selected, each of the slots of the tray has an associated value (rank and suit) corresponding to the desired predetermined sequence. In operation, each card is read for its value. The controller then causes the tray to be moved to align the slot with the value of the read card into a position to accept the read card. The controller then causes the read card to be moved into the slot by a card feed mechanism consisting of a series of rollers in the preferred embodiment. The next card is then read, and the tray is moved to align the slot assigned to this card, which is then moved into the slot. This process is repeated until all of the cards in the stack have been placed in the tray in the predetermined sequence. The tray is then rapidly spun so that the cards are removed from the tray to form a sorted stack with the cards in the predetermined sequence, which can then be removed.
The random number generator, when the random mode (or "shuffle") for the predetermined sequence is selected, assures that the shuffled deck is random. Preferably, a random number generator such as that currently used in electronic poker machines and that has been approved by a gaming commission is used, so no additional gaming commission approvals will be required. The electronic random number generator and subsequent sorting into the sequence generated provides a degree of randomness that is beyond the capability of mechanical processes and is universally approved by gaming commissions. By reading the cards as they are sorted into the electronically generated random sequence, the randomness can be demonstrated by comparing the sequence of the cards in the stack after the shuffle to the generated random number as well as to the original unsorted stack.
As stated above, one reason that mechanical shufflers and human dealers fail to achieve randomness is that several cards are often moved together and may remain adjacent through several shuffles ("riffles"). The prior art shufflers cannot detect when multiple cards have been moved, so the possibility is always present that several cards could remain together through out a shuffle. The preferred embodiment of the automatic card sorter counts each card as it is read. When a smaller number of cards is counted, the possibility exists that the sorter mistakenly moved two or more cards at once into the same slot of the tray. While the tray and mechanism for moving the cards have been designed to move only one card at a time, the sorter further assures this result by counting the cards read. If fewer than the expected number of cards is counted, the automatic card sorter will alert the operator by appropriate output means, and the stack can be removed and replaced.
Because each card in the stack is read, the controller can store in memory the sequence of the original stack of cards as well as count the cards in the stack. By counting and reading the cards, the present invention verifies that the correct number of cards having proper rank and suit is present, thereby alleviating the possibility that cards have been removed, added, or substituted (i.e., replacing "5's" with face cards) during previous play. Once the operator inputs the number of decks present in the stack, the sorter can recall from memory the correct number of each rank and suit that should be present in the stack. While reading the cards in the stack, the controller can keep track of the cards read and alert the operator through appropriate output means of the low or high count. If fewer or more than a certain suit or rank are found, the controller alerts the operator through appropriate output devices that the stack has been subjected to tampering thus verifying the integrity of the deck and eliminating one of the favorite methods of card cheats.
The automatic card sorter of the present invention also eliminates wear to the surface of the playing cards. Only one "pass" is required in contrast to the many "riffles" used by human dealers or multiple shuffles required by mechanical shufflers imitating human motions. The automatic card sorter moves each card only once achieving true randomness, whereas the prior art methods require several movements resulting in greater wear while not achieving complete randomness. When such randomness is predetermined by a computer and achieved by reading and then relocating the card, the wear on the card surface is reduced accordingly because only one movement of each card per shuffle is required, whereas with a dealer or mechanical devices, several "riffles" are often conducted in an attempt to achieve randomness.
An additional advantage of the automatic card sorter over the prior art mechanical shufflers is that it can store in memory a series of predetermined sequences. This series could be recalled later to show, for example, the sequence of every sleeve or stack dealt at a given table where the automatic card sorter is installed. This information, when combined with other devices that keep track of the players at a gaming table and the hands dealt to those players, could be used to verify the winning hands at the table.
Thus, a single device is provided that is compact, can be mounted on a gaming table, and requires little operator skill or training. To operate, the operator simply places a stack of cards in a deck holding area, through which the cards are presented to the card reader (or read heads), inputs the number of decks in the stack, and selects the desired predetermined sequence. The tray and card feed mechanism are enclosed thereby shielding the entire sort from the view of the players and dealer. Thus, the present invention provides a single device and process capable of sorting into a random, new, game play, or other predetermined sequence that, in the preferred embodiment, is fast and free of annoying sounds or vibrations.