Fix bug in Kluepfel strategy

Author: gaffney2010

axelrod/strategies/axelrod_second.py

@@ -536,11 +536,11 @@ def strategy(self, opponent: Player) -> Action:
                     self.dd_counts += 1
             else:
                 if opponent.history[-1] == C:
-                    self.dc_counts += 1
-                else:
                     self.cc_counts += 1
+                else:
+                    self.dc_counts += 1
 
-        # Check for randomness
+        # Check for "randomness"
         if len(self.history) > 26:
             if self.cd_counts >= (self.cd_counts + self.dd_counts) / 2 - 0.75 * np.sqrt(
                 self.cd_counts + self.dd_counts

axelrod/tests/strategies/test_axelrod_second.py

@@ -546,7 +546,12 @@ class TestKluepfel(TestPlayer):
     }
 
     def test_strategy(self):
-        actions = [(C, C)] * 100  # Cooperate forever
+        actions = [(C, C)] * 27  # Cooperate at first
+        # After this point, the strategy will always detect false, becasue the
+        # two checks become:
+        # 0 >= 0, and
+        # cc_counts >= (cc_counts)/2 - 0.75*sqrt(cc_counts)
+        actions += [(D, C)] * 100
         self.versus_test(axelrod.Cooperator(), expected_actions=actions)
 
         # Since never two in a row, will respond in kind with 70% if
@@ -598,16 +603,12 @@ def test_strategy(self):
             (D, C),
             (C, C),
             (C, D),
-            # Success detect random opponent for remaining turns.
-            (D, D),
-            (D, D),
-            (D, D),
-            (D, C),
-            (D, D),
-            (D, C),
-            (D, D),
+            (C, D),
             (D, C),
-            (D, D),
+            (C, C),
+            (C, C),
+            (D, D),  # At this point cc_counts=10, cd_counts=10, dc_counts=10,
+                     # and dd_counts=5.  Detect random and defect hereafter.
             (D, C),
             (D, C),
             (D, D),
@@ -617,11 +618,7 @@ def test_strategy(self):
             (D, C),
             (D, C),
             (D, D),
-            (D, C),
-            (D, C),
-            (D, C),
-            (D, C),
-            (D, D),
+            (D, C)
         ]
         self.versus_test(axelrod.Random(0.5), expected_actions=actions, seed=10)