diff --git a/bdm_voxel_builder/agent.py b/bdm_voxel_builder/agent.py
index f3cd29e..a04096b 100644
--- a/bdm_voxel_builder/agent.py
+++ b/bdm_voxel_builder/agent.py
@@ -114,7 +114,6 @@ def analyze_relative_position(self, grid: Grid):
         self.relative_booleans_bottom_up = [below, aside, above]
         return below, aside, above
 
-
     def direction_preference_6_pheromones(self, x=0.5, up=True):
         """up = 1
         side = x
@@ -579,7 +578,7 @@ def move_on_ground_by_ph_cube(
         # print('choice:', choice)
         new_pose = cube[choice]
         # print('new_pose:', new_pose)
-        
+
         if self.save_move_history:
             v = new_pose - self.pose
             self.move_history.append(v)
@@ -802,25 +801,29 @@ def get_chance_by_pheromone_strength(
                 return v * strength
         else:
             return 0
-    
+
     def match_vertical_move_history_string(
-        self, last_moves_pattern = ['up', 'up', 'side'], value = 1
+        self, last_moves_pattern=("up", "up", "side"), value=1
     ):
         "chance is returned based on the direction values and chance_weight"
         n = len(last_moves_pattern)
         for i in range(n):
             x, y, z = self.move_history[-i]
             pattern = last_moves_pattern[-i]
-            if pattern == 'up' and z > 0:
-                flag = True
-            elif pattern == 'side' and z == 0:
+            if (
+                pattern == "up"
+                and z > 0
+                or pattern == "side"
+                and z == 0
+                or pattern == "down"
+                and z < 0
+            ):
                 flag = True
-            elif pattern == 'down' and z < 0:
-                flag = True
-            else: flag = False
+            else:
+                flag = False
         if flag:
             return value
-        else: 
+        else:
             return 0
 
     #  BUILD/ERASE FUNCTIONS
diff --git a/bdm_voxel_builder/agent_algorithms/algo_8_e_build_ridge.py b/bdm_voxel_builder/agent_algorithms/algo_8_e_build_ridge.py
index 423dcbe..d5c8db8 100644
--- a/bdm_voxel_builder/agent_algorithms/algo_8_e_build_ridge.py
+++ b/bdm_voxel_builder/agent_algorithms/algo_8_e_build_ridge.py
@@ -244,8 +244,12 @@ def move_agent(self, agent: Agent, state: Environment):
         move_pheromon_cube = agent.get_direction_cube_values_for_grid(
             pheromon_grid_move, 1
         )
-        directional_bias_cube_up = agent.direction_preference_26_pheromones_v2(1, 0.5, 0.1)
-        directional_bias_cube_side = agent.direction_preference_26_pheromones_v2(0.1, 1, 0.5)
+        directional_bias_cube_up = agent.direction_preference_26_pheromones_v2(
+            1, 0.5, 0.1
+        )
+        directional_bias_cube_side = agent.direction_preference_26_pheromones_v2(
+            0.1, 1, 0.5
+        )
 
         ############################################################################
         # CHANGE MOVE BEHAVIOUR ####################################################
@@ -302,27 +306,25 @@ def calculate_build_chances(self, agent: Agent, state: Environment):
         ##########################################################################
         # build probability settings #############################################
         ##########################################################################
-        low_density__build_reward = 0 #0.1
+        low_density__build_reward = 0  # 0.1
         low_density__erase_reward = 0
 
-        normal_density__build_reward = 0 #0.3
+        normal_density__build_reward = 0  # 0.3
         normal_density__erase_reward = 0
 
         high_density__build_reward = 0
         high_density__erase_reward = 1.5
 
         step_on_ridge_reward = 1.5
-        step_on_ridge_moves_pattern = ['side', 'up', 'up']
+        step_on_ridge_moves_pattern = ["side", "up", "up"]
 
         ##########################################################################
 
-
-
         # get clay density
         clay_density = agent.get_grid_density(grid)
         dense_mod = clay_density + 0.2
         clay_density_filled = agent.get_grid_density(grid, nonzero=True)
-        
+
         # set chances based on clay density
         if 1 / 26 <= clay_density_filled < 3 / 26:
             build_chance += low_density__build_reward * dense_mod
@@ -333,10 +335,12 @@ def calculate_build_chances(self, agent: Agent, state: Environment):
         elif clay_density_filled >= 4 / 5:
             build_chance += high_density__build_reward * dense_mod
             erase_chance += high_density__erase_reward
-        
+
         # set chances based on movement pattern __
-        movement_pattern_gain = agent.match_vertical_move_history_string(step_on_ridge_moves_pattern, step_on_ridge_reward)
-        if 1/26 <= clay_density_filled:
+        movement_pattern_gain = agent.match_vertical_move_history_string(
+            step_on_ridge_moves_pattern, step_on_ridge_reward
+        )
+        if clay_density_filled >= 1 / 26:
             build_chance += movement_pattern_gain
 
         # update probabilities
diff --git a/bdm_voxel_builder/helpers/geometry.py b/bdm_voxel_builder/helpers/geometry.py
index 7fa0b0b..7887d5a 100644
--- a/bdm_voxel_builder/helpers/geometry.py
+++ b/bdm_voxel_builder/helpers/geometry.py
@@ -61,7 +61,6 @@ def _get_xform_box2grid(
     return Sc, R, Tl
 
 
-
 def get_translation_box2grid(
     box: cg.Box, grid_size: tuple[int, int, int]
 ) -> cg.Translation: