# Source code for axelrod.strategies.worse_and_worse

```
from axelrod.action import Action
from axelrod.player import Player
from axelrod.random_ import random_choice
C, D = Action.C, Action.D
[docs]class WorseAndWorse(Player):
"""
Defects with probability of 'current turn / 1000'. Therefore
it is more and more likely to defect as the round goes on.
Source code available at the download tab of [Prison1998]_
Names:
- Worse and Worse: [Prison1998]_
"""
name = "Worse and Worse"
classifier = {
"memory_depth": float("inf"),
"stochastic": True,
"makes_use_of": set(),
"long_run_time": False,
"inspects_source": False,
"manipulates_source": False,
"manipulates_state": False,
}
[docs] def strategy(self, opponent: Player) -> Action:
current_round = len(self.history) + 1
probability = 1 - current_round / 1000
return random_choice(probability)
[docs]class KnowledgeableWorseAndWorse(Player):
"""
This strategy is based on 'Worse And Worse' but will defect with probability
of 'current turn / total no. of turns'.
Names:
- Knowledgeable Worse and Worse: Original name by Adam Pohl
"""
name = "Knowledgeable Worse and Worse"
classifier = {
"memory_depth": float("inf"),
"stochastic": True,
"makes_use_of": set(["length"]),
"long_run_time": False,
"inspects_source": False,
"manipulates_source": False,
"manipulates_state": False,
}
[docs] def strategy(self, opponent: Player) -> Action:
current_round = len(self.history) + 1
expected_length = self.match_attributes["length"]
probability = 1 - current_round / expected_length
return random_choice(probability)
[docs]class WorseAndWorse2(Player):
"""
Plays as tit for tat during the first 20 moves.
Then defects with probability (current turn - 20) / current turn.
Therefore it is more and more likely to defect as the round goes on.
Names:
- Worse and Worse 2: [Prison1998]_
"""
name = "Worse and Worse 2"
classifier = {
"memory_depth": float("inf"),
"stochastic": True,
"makes_use_of": set(),
"long_run_time": False,
"inspects_source": False,
"manipulates_source": False,
"manipulates_state": False,
}
[docs] def strategy(self, opponent: Player) -> Action:
current_round = len(self.history) + 1
if current_round == 1:
return C
elif current_round <= 20:
return opponent.history[-1]
else:
probability = 20 / current_round
return random_choice(probability)
[docs]class WorseAndWorse3(Player):
"""
Cooperates in the first turn.
Then defects with probability no. of opponent defects / (current turn - 1).
Therefore it is more likely to defect when the opponent defects for a larger
proportion of the turns.
Names:
- Worse and Worse 3: [Prison1998]_
"""
name = "Worse and Worse 3"
classifier = {
"memory_depth": float("inf"),
"stochastic": True,
"makes_use_of": set(),
"long_run_time": False,
"inspects_source": False,
"manipulates_source": False,
"manipulates_state": False,
}
[docs] def strategy(self, opponent: Player) -> Action:
current_round = len(self.history) + 1
if current_round == 1:
return C
else:
probability = 1 - opponent.defections / (current_round - 1)
return random_choice(probability)
```