diff --git a/board.py b/board.py
index 717b168..84607c1 100644
--- a/board.py
+++ b/board.py
@@ -1,6 +1,5 @@
 import os
 import random
-import math
 from datetime import datetime
 
 
@@ -134,8 +133,8 @@ class Move:
     # needing own analysis ready
     @property
     def temperature_stats(self):
-        best = float(self.analysis[0]["scoreLead"])
-        worst = float(self.pass_analysis[0]["scoreLead"])
+        best = self.analysis[0]["scoreLead"]
+        worst = self.pass_analysis[0]["scoreLead"]
         return best, worst, max(-self.player_sign * (best - worst), 0)
 
     @property
@@ -150,15 +149,21 @@ class Move:
     @property
     def evaluation(self):
         best, worst, temp = self.parent.temperature_stats
-        return self.player_sign * (self.score - worst) / temp if temp > 0 else math.nan
+        return self.player_sign * (self.score - worst) / temp if temp > 0 else None
 
     @property
     def outdated_evaluation(self):
+        def outdated_score(move_dict):
+            return move_dict.get("outdatedScoreLead") or move_dict["scoreLead"]
+
         prev_analysis_current_move = [d for d in self.parent.analysis if d["move"] == self.gtp()]
         if prev_analysis_current_move:
             best_score, worst_score, prev_temp = self.parent.temperature_stats
-            score = prev_analysis_current_move[0].get("outdatedScoreLead") or prev_analysis_current_move[0]["scoreLead"]
-            return self.player_sign * (score - worst_score) / prev_temp if prev_temp > 0 else math.nan
+            best_score = outdated_score(self.parent.analysis[0])
+            worst_score = self.parent.pass_analysis[0]["scoreLead"]
+            prev_temp = max(self.player_sign * (best_score - worst_score), 0)
+            score = outdated_score(prev_analysis_current_move[0])
+            return self.player_sign * (score - worst_score) / prev_temp if prev_temp > 0 else None
 
     @property
     def ai_moves(self):
diff --git a/controller.py b/controller.py
index 2afc801..27da4e0 100644
--- a/controller.py
+++ b/controller.py
@@ -1,7 +1,6 @@
 import copy
 import json
 import os
-import math
 import random
 import re
 import shlex
@@ -98,7 +97,7 @@ class EngineControls(GridLayout):
             self.score.text = move.format_score().replace("-", "\u2013")
             self.temperature.text = f"{move.temperature_stats[2]:.1f}"
             if move.parent and move.parent.analysis_ready:
-                if not math.isnan(move.evaluation):
+                if move.evaluation is not None:
                     self.evaluation.text = f"{move.evaluation:.1%}"
                 else:
                     self.evaluation.text = f"?"
@@ -107,7 +106,7 @@ class EngineControls(GridLayout):
     def update_evaluation(self):
         current_move = self.board.current_move
         self.score.set_prisoners(self.board.prisoner_count)
-        current_player_is_human_or_both_robots = (not self.ai_auto.active(current_move.player) or self.ai_auto.active(1 - current_move.player))
+        current_player_is_human_or_both_robots = not self.ai_auto.active(current_move.player) or self.ai_auto.active(1 - current_move.player)
         if current_player_is_human_or_both_robots and current_move is not self.board.root:
             self.info.text = current_move.comment(eval=True, hints=self.hints.active(current_move.player))
         self.evaluation.text = ""