Canfield or Demon is a patience or solitaire card game with a very low probability of winning. It is originally a casino game, and in the United States is named after casino owner Richard A. Canfield, who popularised it in the 1890s.
Origin
Noted gambler Richard A. Canfield owned the Canfield Casino in Saratoga Springs, New York during the 1890s. Gamblers at his casino would play the game by "buying" a deck of cards for $50. The gambler would then play the game and earn $5 for every card they managed to place into the foundations; if a player was fortunate enough to place all 52 cards into the foundations, the player would win $500. Although players made a loss on average, the game proved to be popular, and Canfield became rich. The disadvantage of this new game was the need to hire a croupier for every gambler playing the game. Canfield himself called the game Klondike, but the name Canfield stuck in North American circles. Confusingly, Canfield is also the traditional name for a different solitaire game that was later renamed Klondike in North America, and which is the most popular form of solitaire that most people are familiar with.
Method of play
To play the game, one must first deal thirteen cards faced up and then turned down. These cards would be the reserve, the top card of which is available for play. Then a card is placed on first of the four foundations to the right of the reserve. This card is the first card of its foundation and all other cards of the same rank must also start the other three foundations. Below the foundations are four piles, each starting with a card each. This will be the tableau and the top cards of each pile are available for play. Cards on the tableau are built down by alternating colors, while the foundations are built up by suit, wrapping from King to Ace if necessary. Any gaps on the tableau are filled from the reserve; in case the reserve is used up, cards from the waste pile are used. Cards on the reserve can also be distributed to the foundations or to the tableau. Cards on the tableau are also moved one unit, provided that the entire column has to be moved. When no more plays are possible on the tableau and no more cards can be placed to the foundations, especially from the reserve, one can deal cards from the stock three at a time into the waste pile and use these cards to build to the foundations or to the tableau. One can make unlimited redeals as long as there are moves, although Richard Canfield himself restricted the number of times that gamblers could redeal the stock. The game is won when all cards are placed in the foundations. But as Canfield knew very well, winning this game is unlikely, as one can manage to place an average of five to six cards.
Variations
Some variations to the game include:
Chameleon, where the reserve only has 12 cards, and there are only three tableau columns. Building in the tableau is down, regardless of suit, and the stock is dealt one at a time with no redeals. All or any cards may be moved from the end of one tableau pile to another.
Rainbow Canfield, in which the tableau builds down regardless of suit. Cards are turned one at a time and no redeals are allowed.
Selective Canfield, where one can deal five cards right after the reserve is dealt. One can place any one of these five into the foundations and the remaining four cards become the tableau.
Storehouse Canfield, in which one should remove the deuces and place them on the foundations. The reserve and the cards on the tableau are then dealt. The stock is dealt one card at a time, and it can be used only twice. Furthermore, the method of building in this game is by suit.
Superior Canfield, where the entire reserve is visible, and gaps can be filled by any card, not just those from the reserve.
Other closely related solitaire games include American Toad and Duchess. Nerts is a real-time variant of Canfield that enables the game to be played competitively between multiple players. It was the inspiration for the commercially produced Dutch Blitz and Ligretto.
Solvability
Running a computer solver on 50,000 random Canfield deals has shown that between 71% and 72% of all games are possible to win. In the average game, 40 cards were moved to the foundation. Because the reserve cards are hidden, and because the three-at-a-time dealing of cards from the stock means that cards played early in the game can impact which stock cards are available much later, it is very difficult by normal playing standards to come anywhere near theoretically possible win rates. The highest potential win rates for strategic expert-level players averages at about 35%. In the Storehouse variant, a greater potential to win increases rates to about 44% proportional to games played. In practice, however, Storehouse is a much easier game. Most players will easily be able to win close to 44% of games, a much higher win rate than is ever achieved by casual players of Canfield.
