Axelrod’s celebrated Prisoner’s Dilemma computer tournaments, published in the early 1980s, were designed to find effective ways of acting in everyday interactions with the strategic properties of the iterated Prisoner’s Dilemma game. The winner of both tournaments was tit-for-tat, a program that cooperates on the first round and then, on every …

axelrod-game-theory.json

[
    {
        "Program": 1,
        "Name": "TFT",
        "Full Name": "Tit For Tat",
        "Description": "TIT FOR TAT starts with a cooperative choice, and thereafter does what the other player did on the previous move. If the opponent cooperates, the program also does next round, and vice-versa",
        "Author": [
            "Anatol Rapoport"
        ],
        "University": "University of Toronto",
        "Location": "Toronto",
        "State": "Ontario",
        "Country": "Canada",
        "Department": "Psychology",
        "% Preliminary": 42.1,
        "% Wins": 11.0,
        "Nice": true,
        "Kingmaker": false
    },
    {
        "Program": 2,
        "Name": "T&C",
        "Full Name": "Tideman & Cheruzzi",
        "Description": "This rule begins with cooperation and tit for tat. However, when the other player finishes his second run of defections, an extra punishment is instituted, and the number of punishing defections is increased by one with each run of the other’s defections. The other player is given a fresh start if he is 10 or more points behind, if he has not just started a run of defections. if it has been at least 20 moves since a fresh start, if there are at least 10 moves remaining, and if the number af defections differs from a 50-50 random generator by at least 3.0 standard deviations. A fresh start involves two cooperations and then play as if the game had just started. The program defects automatically on the last two moves.",
        "Author": [
            "Nicolas Tideman",
            "Paula Cheruzzi"
        ],
        "University": "Virginia Polytechnic Institute and State University",
        "Location": "Blacksburg",
        "State": "Virginia",
        "Country": "USA",
        "Department": "Economics",
        "% Preliminary": 41.4,
        "% Wins": 30.0,
        "Nice": true,
        "Kingmaker": false
    },
    {
        "Program": 3,
        "Name": "NY",
        "Full Name": "Nydegger",
        "Author": [
            "Rudy NYDEGGER"
        ],
        "Description": "The program begins with tit for tat for the first three moves, except that if it was the only one to cooperate on the first move and the only one to defect on the second move, it defects on the third move. After the third move, its choice is determined from the 3 preceding outcomes in the following manner. Let A be the sum formed by counting the other’s defection as 2 points and one’s own as 1 point, and giving weights of 16, 4. and 1 to the preceding three moves in chronological order. The choice can be described as defecting only when A equals I, 6,7. 17,22,23,26,29,30,31,33,38,39,45,49,54,55.58, or 61. Thus if all three preceding moves are mutual defection, A = 63 and the rule cooperates. This rule was designed for use in laboratory experiments as a stooge which had a memory and appeared to be trustworthy, potentially cooperative, but not gullible.",
        "University": "Union College",
        "Location": "Schenectady",
        "State": "New York",
        "Country": "USA",
        "Department": "Psychology",
        "% Preliminary": 41.5,
        "% Wins": 10.2,
        "Nice": true,
        "Kingmaker": false
    },
    {
        "Program": 4,
        "Name": "GR",
        "Full Name": "Grofman",
        "Author": [
            "Bernard Grofman"
        ],
        "Description": "e. If the players did different things on the previous move, this rule cooperates with probability 2/7. Otherwise this rule always cooperates.",
        "University": "University of California, Irvine",
        "Location": "Irvine",
        "State": "California",
        "Country": "USA",
        "Department": "Political Science",
        "% Preliminary": 31.0,
        "% Wins": 10.0,
        "Nice": true,
        "Kingmaker": false
    },
    {
        "Program": 5,
        "Name": "SH",
        "Full Name": "Shubik",
        "Description": "SHUBIK is progressively less forgiving: It starts by always cooperating, punishes the first defection with one defection, then punishes the next with two defections, and so on.",
        "University": "Yale University",
        "Author": [
            "Martin Shubik"
        ],
        "State": "Connecticut",
        "Country": "USA",
        "Department": "Economics",
        "Location": "New Haven",
        "% Preliminary": 24.4,
        "% Wins": 6.7,
        "Nice": true,
        "Kingmaker": false
    },
    {
        "Program": 6,
        "Name": "S&R",
        "Full Name": "Stein & Rapoport",
        "Author": [
            "William Stein",
            "Anatol Rapoport"
        ],
        "Description": " This rule plays tit for tat except that it cooperates on the first four moves, it defects on the last two moves, and every fifteen moves it checks to see if the opponent seems to be playing randomly. This check uses a chi-squared test of the other’s transition probabilities and also checks for alternating moves of CD and DC.",
        "University": "Texas Christian University",
        "Location": "Fort Worth",
        "State": "Texas",
        "Country": "USA",
        "Department": "Mathematics",
        "% Preliminary": 39.9,
        "% Wins": 24.8,
        "Nice": true,
        "Kingmaker": false
    },
    {
        "Program": 7,
        "Name": "FR",
        "Full Name": "Friedman",
        "Author": [
            "James W. Friedman"
        ],
        "Description": "FRIEDMAN is cooperative until the other player defects, then it never cooperates again.",
        "University": "University of Rochester",
        "Location": "Rochester",
        "State": "New York",
        "Country": "USA",
        "Department": "Economics",
        "% Preliminary": 21.1,
        "% Wins": 4.9,
        "Nice": true,
        "Kingmaker": false
    },
    {
        "Program": 8,
        "Name": "DA",
        "Full Name": "Davis",
        "Author": [
            "Morton Davis"
        ],
        "University": "City College - CUNY",
        "State": "New York",
        "Location": "New York",
        "Country": "USA",
        "Department": "Mathematics",
        "Description": "This rule cooperates on the first ten moves, and then if there is a defection it defects until the end of the game.",
        "% Preliminary": 13.8,
        "% Wins": 2.1,
        "Nice": true,
        "Kingmaker": false
    },
    {
        "Program": 9,
        "Name": "GR",
        "Full Name": "Graaskamp",
        "Author": [
            "James Graaskamp"
        ],
        "University": "Beloit College",
        "Location": "Beloit",
        "State": "Wisconsin",
        "Country": "USA",
        "Department": null,
        "Description": "This rule plays tit for tat for 50 moves, defects on move 51, and then plays 5 more moves of tit for tat. A check is then made to see if the player seems to be RANDOM, in which case it defects from then on. A check is also made to see if the other is TIT FOR TAT, ANALOGY (a program from the preliminary tournament), and its own twin, in which case it plays tit for tat. Otherwise it randomly defects every 5 to 15 moves, hoping that enough trust has been built up so that the other player will not notice these defections.",
        "% Preliminary": 11.8,
        "% Wins": 0.2,
        "Nice": false,
        "Kingmaker": true
    },
    {
        "Program": 10,
        "Name": "DO",
        "Full Name": "Downing",
        "Description": "This rule selects its choice to maximize its own longterm expected payoff on the assumption that the other rule cooperates with a fixed probability which depends only on whether the other player cooperated or defected on the previous move. These two probabilities estimates are continuously updated as the game progresses. Initially, they are both assumed to be 0.5, which amounts to the pessimistic assumption that the other player is not responsive. This rule is based on an outcome maximization interpretation of human performances proposed by Downing.",
        "Author": [
            "Leslie DOWNING"
        ],
        "University": "Union College",
        "Location": "Schenectady",
        "Country": "USA",
        "State": "New York",
        "Department": "Psychology",
        "% Preliminary": 20.8,
        "% Wins": 0.1,
        "Nice": false,
        "Kingmaker": true
    },
    {
        "Program": 11,
        "Name": "FE",
        "Full Name": "Feld",
        "Author": [
            "Scott Feld"
        ],
        "University": "University of California, Riverside",
        "Location": "Riverside",
        "State": "California",
        "Country": "USA",
        "Department": "Sociology",
        "Description": "This rule starts with TIT FOR TAT and gradually lowers its probability of cooperation following the other’s cooperation to 0.5 at the end of the game. It always defects after a defection by the other.",
        "% Preliminary": 7.7,
        "% Wins": 0.0,
        "Nice": false,
        "Kingmaker": false
    },
    {
        "Program": 12,
        "Name": "JO",
        "Full Name": "Joss",
        "Author": [
            "Johann JOSS"
        ],
        "Description": "JOSS, as a decision rule, is a variation of TIT FOR TAT. Like TIT FOR TAT, it always defects immediately after the other player defects. But instead of always cooperating after the other player cooperates, 10% of the time it defects after the other player cooperates. Thus it tries to get away with an occasional exploitation of the other player.",
        "University": "Eidgenossishe Technische Hochschule",
        "Location": "Zurich",
        "State": "Kanton Zürich",
        "Country": "Switzerland",
        "% Preliminary": 2.5,
        "% Wins": 0.0,
        "Nice": false,
        "Kingmaker": false
    },
    {
        "Program": 13,
        "Name": "TU",
        "Full Name": "Tullock",
        "Author": [
            "Gordon Tullock"
        ],
        "University": "Virginia Polytechnic Institute and State University",
        "Location": "Blacksburg",
        "State": "Virginia",
        "Country": "USA",
        "Department": "Political Science",
        "Description": "This rule cooperates on the first eleven moves. It then cooperates 10% less than the other player has cooperated on the preceding ten moves.",
        "% Preliminary": 0.4,
        "% Wins": 0.0,
        "Nice": false,
        "Kingmaker": false
    },
    {
        "Program": 14,
        "Name": null,
        "Full Name": "Name Withheld",
        "Author": [
            "A student"
        ],
        "Department": "Political Science",
        "Country": null,
        "Location": null,
        "State": null,
        "University": null,
        "Description": "This rule has a probability of cooperating, P, which is initially 30% and is updated every 10 moves. P is adjusted if the other player seems random, very cooperative, or very uncooperative. P is also adjusted after move 130 if the rule has a lower score than the other player. Unfortunately, the complex process of adjustment frequently left the probability of cooperation in the 30% to 70% range, and therefore the rule appeared random to many other players.",
        "% Preliminary": 1.2,
        "% Wins": 0.0,
        "Nice": false,
        "Kingmaker": false
    },
    {
        "Program": 15,
        "Name": "RAND",
        "Author": [],
        "Country": null,
        "Location": null,
        "State": null,
        "University": null,
        "Full Name": "Random",
        "Department": null,
        "Description": "This program randomly cooperates or defects with a purely random chance of 0.5",
        "% Preliminary": 0.5,
        "% Wins": 0.0,
        "Nice": false,
        "Kingmaker": false
    }
]