3 ms·

Covered in some detail in Robert Axelrod's "Evolution of Cooperation" from 1984 [0] which is a book resulting from the original paper with W D Hamilton. Anatol

by hazeii 6y ago

Covered in some detail in Robert Axelrod's "Evolution of Cooperation" from 1984 [0] which is a book resulting from the original paper with W D Hamilton. Anatol Rappaport submitted "Tit for tat" as a strategy in a computerised tournament of programs adressing the Prisoners Dilemma, , and it wiped the floor with the opposition. I don't recall the full details, there was a second round with some restrictions, Rappaport simply submitted TfT again and it came out well even with constraints on it. [0] https://en.wikipedia.org/wiki/The_Evolution_of_Cooperation https://en.wikipedia.org/wiki/The_Evolution_of_Cooperation

alasdair_ 6y ago
There is actually a better strategy than tit for tat, for iterated prisoner's dilemma played in a tournament setting where the winner is determined by total score at the end of all rounds. The strategy is to submit lots of entrants to the tournament rather than just one, then play tit for tat against all opponents except those that are in the clique. The clique players then lose on purpose to a specifically-chosen player, maximizing that players score. If you don't want to do it this way and instead care about maximizing the total scores of the clique as a whole, you can default to every clique member always cooperating. Even in cases where the opponent is "blind", you can use a special pattern of bets to signal that the other player is a member of the clique and then play your win-maximizing strategy once the signal is detected. This kind of thing has real-world implications. For example: imagine a poker game with ten players, all of the same skill level and without a rake. Nine of the players can collude (say, show each other their hidden cards and make decisions based on the shared information), making it significantly less likely than a 10% chance that the targeted player will win. I suspect this is already done to an extent in extremely high-stakes games (say, $1MM+).
- lonelappde 6y ago
  It's trivial to say that cheating in a competition is a winning strategy as long as you don't get caught and punished.
  - alasdair_ 6y ago
    At lease for standard iterated prisoners dilemma AI tournaments, this strategy was completely legal - I read about it severals years ago when it was first used to win a prominent one. The poker one already happens in real life all the time - if friends go to play at the same table, they often play differently than with a stranger.

by hazeii 6y ago

alasdair_ 6y ago

There is actually a better strategy than tit for tat, for iterated prisoner's dilemma played in a tournament setting where the winner is determined by total score at the end of all rounds. The strategy is to submit lots of entrants to the tournament rather than just one, then play tit for tat against all opponents except those that are in the clique. The clique players then lose on purpose to a specifically-chosen player, maximizing that players score. If you don't want to do it this way and instead care about maximizing the total scores of the clique as a whole, you can default to every clique member always cooperating. Even in cases where the opponent is "blind", you can use a special pattern of bets to signal that the other player is a member of the clique and then play your win-maximizing strategy once the signal is detected. This kind of thing has real-world implications. For example: imagine a poker game with ten players, all of the same skill level and without a rake. Nine of the players can collude (say, show each other their hidden cards and make decisions based on the shared information), making it significantly less likely than a 10% chance that the targeted player will win. I suspect this is already done to an extent in extremely high-stakes games (say, $1MM+).

lonelappde 6y ago
It's trivial to say that cheating in a competition is a winning strategy as long as you don't get caught and punished.
- alasdair_ 6y ago
  At lease for standard iterated prisoners dilemma AI tournaments, this strategy was completely legal - I read about it severals years ago when it was first used to win a prominent one. The poker one already happens in real life all the time - if friends go to play at the same table, they often play differently than with a stranger.