Prisoner's Dilemma strategies
Always Cooperate
Co-operate on every move, whatever the opponent does.
Played by Amberdale Union
Where it comes from
The baseline nice strategy, used in every tournament as a control. It is what people usually mean by co-operation before they have thought about it for long.
How it plays
Always Cooperate is the strategy everybody sympathises with and nobody should copy. Against other co-operative strategies it does exactly as well as the best of them, because mutual co-operation is mutual co-operation however you arrived at it. The problem is that it hands a maximum pay-off to every defector it meets, and pays the worst outcome available in the game to do it.
The technical term for the flaw is that it does not retaliate, and Axelrod's tournaments were unambiguous about what that costs. Being nice was strongly associated with doing well. Being nice without a response was not the same property, and the strategies that carried the first without the second were the food supply for everyone else.
On a pitch it is a side that competes honestly for the ball all afternoon and never once makes a cynical challenge, no matter what has been done to it. It keeps the ball better than anyone and creates chances nobody else creates, because it spends nothing on the fight. Then it plays the league's aggressors and gives up free chances all game.
Its real value in a tournament is as a measurement rather than a competitor. How a league treats Always Cooperate tells you how much of the field is willing to exploit the defenceless, which is a more interesting number than where the strategy itself finishes.
In this league
Amberdale Union of Amberdale play Always Cooperate. That decency is worth keeping even when the table says otherwise. They have not played yet this season.