To operate Pokerac, a user selected five cards from the coded deck and inserted one card into each slot. Cards could either face away from the user (to play against the machine) or face forward (for demonstrations).
To operate Pokerac, a user selected five cards from the coded deck and inserted one card into each slot. Cards could either face away from the user (to play against the machine) or face forward (for demonstrations).
[[File:Pokerac operation 1 backs.png|thumb|left|450px|Cards inserted with backs visible]]
[[File:Pokerac operation 1 backs.png|thumb|450px|Cards inserted with backs visible]]
[[File:Pokerac operation 2 fronts.png|thumb|left|450px|Cards inserted with fronts visible]]
[[File:Pokerac operation 2 fronts.png|thumb|left|450px|Cards inserted with fronts visible]]
David Dewan demonstrating Pokerac in 1961 |
|
| Type | Game-playing computer |
|---|---|
| Release date | May 1961 |
| Media | Punched cards |
| CPU | Relay-based logic circuits |
| Display | Indicator lights |
| Input | Manual card insertion |
Pokerac was a poker-playing computer invented in 1961 by high school senior David Dewan. The machine used relay-based logic circuits to play two-handed five-card draw poker with no wild cards.
According to Dewan’s evaluation, Pokerac won approximately 60 percent of games against average poker players and achieved a 50-50 split against skilled players.[1]
David Dewan, an 18-year-old senior at Niskayuna High School (Schenectady, New York)[2], began developing Pokerac in late 1960 when he calculated approximately 1000 probability values necessary for playing optimal five-card draw poker.[3] Actual construction of the computer took about 300 hours[4] during late 1960 and early 1961. Total material cost, using surplus relays and a handmade card reader, was $150[5].
Pokerac used stepping switches and relays for its logic circuits. To read the playing cards, a handmade 85-pole selector switch[5] used pairs of spring-loaded contacts on two boards (17 per card). Solenoids clamped the boards together around the cards, and holes in the cards (for suit and rank) allowed the corresponding contacts to touch, translating the hole patterns into electrical signals. These signals then passed through the stepping switches and relay logic circuits which implemented the probability-based decision rules Dewan had calculated earlier. A light in front of each card slot indicated whether to keep or replace that card during the draw phase[6] and lights on the back panel identified the final hand classification.[7]
Pokerac used coded playing cards[8] with holes punched in specific positions to identify each card’s suit and rank. A notch at the bottom of the card ensured proper alignment when inserted into one of the machine’s card slots.
Diagram of Pokerac playing card showing hole positions for encoding suit and rank.
Pokerac playing card showing the hole for “2”, the hole for “Hearts”, and the alignment notch at the bottom.
To operate Pokerac, a user selected five cards from the coded deck and inserted one card into each slot. Cards could either face away from the user (to play against the machine) or face forward (for demonstrations).
Recognition and Impact
[edit]
Pokerac attracted attention from both the press and the scientific community. In May 1961, the Schenectady Gazette featured an article about the machine and its inventor[5]. The story was subsequently picked up by United Press International (UPI), giving it national distribution[9].
Dr. Richard Shuey and Dr. C.V. Jakowatz of the General Electric Research Laboratory in Schenectady conducted a two-hour evaluation of the project. Dr. Shuey, who managed the information studies section at the research laboratory, wrote that the machine “demonstrates a high degree of ingenuity and initiative and should be recognized as such.”[5]
Name and Historical Context
[edit]
Pokerac was named in the style of early computers: ENIAC (1945), UNIVAC (1951), and MANIAC (1952).
The concept of computers playing games was in its infancy. Arthur Samuel had developed a self-learning checkers-playing program at IBM in the 1950s. Dedicated game-playing computers such as Fidelity Electronic Checker Challenger (1978) were still far in the future.[10]
General purpose computers, though large, expensive, and generally inaccessible to individuals, were getting smaller. In 1959, IBM had announced the IBM 1401 computer and Digital Equipment Corporation delivered their PDP-1.
- ^ “Pokerac”. The Cleveland Press. Cleveland, Ohio. July 27, 1961. p. 27.
- ^ Jack Reycraft (July 27, 1961). “This Robot’s in the Chips”. Staten Island Advance. Staten Island, New York. p. 12.
- ^ “Poker Face”. The Sault Star. Sault St. Marie, Ontario, Canada. June 1, 1961. p. 23.
- ^ “Poker Face”. The Patriot News. Harrisburg, Pennsylvania. July 25, 1961. p. 3.
- ^ a b c d Howard Krieger (May 28, 1961). “Dave Turns His Hand to Poker, Chips in With Perfect Machine”. Schenectady Gazette. Schenectady, New York. p. 8.
- ^ “Poker Face”. The Republican. Springfield, Massachusetts. May 31, 1961. p. 26.
- ^ “Poker Face”. The Daily Times. Davenport, Iowa. June 15, 1961. p. 23.
- ^ a b c Crossroads (yearbook). Niskayuna, New York: Niskayuna High School. 1961. p. 33.
- ^ “Poker Face”. The Warren County Observer. Warren, Pennsylvania. June 2, 1961. p. 18.
- ^ “Other Electronic Board Games”. Hiarcs Chess Forums. 2017-04-05. Retrieved 2025-12-23.
