Southampton strategy


"Nick Kibourn" <nkilbourn2002@xxxxxxxxxx> wrote in message news:dioln5$usj$1@xxxxxxxxxxxxxxxxxxxxxx
> Tit for Tat is a highly-effective strategy in game theory for the iterated
> prisoner's dilemma. Based on the English saying meaning "equivalent
> retaliation" ("tip for tap"), an agent using this strategy will respond in
> kind to a previous opponent's action. If the opponent previously was
> cooperative, the agent is cooperative. If not, the agent is not.
>
> The success of the strategy, which is largely cooperative, took many by
> surprise. In successive competitions various teams produced complex
> strategies which attempted to "cheat" in a variety of cunning ways, but Tit
> for Tat eventually prevailed in every competition.
>
> Some theorists believe this result may give insight into how groups of
> animals (and particularly human societies) have come to live in largely (or
> entirely) cooperative societies, rather than the individualistic "red in
> tooth and claw" way that might be expected from individual engaged in a
> Darwinian struggle.
>
> In a 2004 tournament Tit for Tat was beaten for the first time. A strategy
> created by the University of Southampton detected (by means of a
> pre-arranged pattern of seemingly random operations) whether its counterpart
> was another instance of the Southampton strategy. In cases where the
> counterpart is determined not to be using the Southampton strategy, it acts
> as a spoiler for the non-Southampton player. In cases where it is, the two
> form a master slave relationship, where the slave sacrifice's itself for the
> master by always cooperating and letting the master get away with never
> cooperating, which maximises the number of points for the master. In the
> competition where hundreds of agents are entered and compete against each
> other, Southampton entered 60 agents, guaranteeing that a few master agents
> gain incredibly high scores by sacrificing the rest of the slaves agents to
> the bottom of the score list.

Wow! Thanks. I hadn't heard of that. But Googling on the search string
Southampton strategy tit-for-tat
turned up a wealth of information.

It seems to be a variant of 'green beard' altruism. But it apparently
relies upon the tournament's rules for reproduction being such that
having a few big Southampton winners (masters) more than makes up for the
miserable score of all those Southampton losers (slaves).

"Reproductive Excess" rears its ugly head again.


.

Relevant Pages

  • Re: Empirically Measuring Mutualism In Man
    ... >> was another instance of the Southampton strategy. ... >> form a master slave relationship, where the slave sacrifice's itself for the ... >> other, Southampton entered 60 agents, guaranteeing that a few master agents ... >> gain incredibly high scores by sacrificing the rest of the slaves agents to ...
    (sci.bio.evolution)
  • Re: Empirically Measuring Mutualism In Man
    ... >>> whether its counterpart was another instance of the Southampton ... >>> form a master slave relationship, where the slave sacrifice's itself for the ... >>> of the slaves agents to the bottom of the score list. ... The Southampton strategy works through a sort of kin selection ...
    (sci.bio.evolution)