diff --git a/README.md b/README.md
index cfbc31e..11bb40a 100644
--- a/README.md
+++ b/README.md
@@ -193,7 +193,6 @@ The system automatically records tracking data from the **active player** (the o
 **Data recording**:
 - Starts automatically when experiment starts
 - Stops automatically when experiment stops
-- Only records from the active player (not the guesser)
 - Exports as CSV with group ID and timestamp in filename
 
 ## Unity Project Details
diff --git a/experiment-scripts/app.py b/experiment-scripts/app.py
index c252748..2f771cf 100644
--- a/experiment-scripts/app.py
+++ b/experiment-scripts/app.py
@@ -80,8 +80,8 @@ async def tracking_listener():
                     source_ip = addr[0]
                     actual_data = message
                 
-                # Only record data from the active player
-                if source_ip == tracking_state["active_player_ip"]:
+                # Record data from both players
+                if source_ip in [tracking_state["player1_ip"], tracking_state["player2_ip"]]:
                     parsed = parse_tracking_data(actual_data)
                     
                     if parsed:
@@ -89,10 +89,24 @@ async def tracking_listener():
                         # Calculate time elapsed since experiment start
                         elapsed_time = time.time() - tracking_state["experiment_start_time"]
                         
+                        # Determine player_ID and role
+                        if source_ip == tracking_state["player1_ip"]:
+                            player_id = "player1"
+                        else:
+                            player_id = "player2"
+                        
+                        # Determine role: active_player_ip is the mimicker
+                        if source_ip == tracking_state["active_player_ip"]:
+                            role = "mimicker"
+                        else:
+                            role = "guesser"
+                        
                         # Add sample with metadata
                         sample = {
                             "timestamp": time.time(),
                             "elapsed_time": elapsed_time,
+                            "player_id": player_id,
+                            "role": role,
                             "current_word": current_word_state["word"],
                             "word_time_remaining": 0.0,
                             "data": parsed
@@ -188,7 +202,9 @@ class VRConfig(BaseModel):
 class TrackingStart(BaseModel):
     group_id: str
     condition: str
-    active_player_ip: str
+    player1_ip: str
+    player2_ip: str
+    active_player_ip: str  # The player who mimics (mimicker)
 
 # Global state for current word display
 current_word_state = {
@@ -203,7 +219,9 @@ tracking_state = {
     "is_recording": False,
     "group_id": "",
     "condition": "",
-    "active_player_ip": "",
+    "player1_ip": "",
+    "player2_ip": "",
+    "active_player_ip": "",  # The mimicker
     "experiment_start_time": None,
     "samples": []  # List of tracking data samples
 }
@@ -369,18 +387,22 @@ def send_vr_config(config: VRConfig):
 @app.post("/tracking/start")
 def start_tracking(config: TrackingStart):
     """
-    Start recording tracking data from the active player.
+    Start recording tracking data from both players.
     """
     import time
     
     tracking_state["is_recording"] = True
     tracking_state["group_id"] = config.group_id
     tracking_state["condition"] = config.condition
+    tracking_state["player1_ip"] = config.player1_ip
+    tracking_state["player2_ip"] = config.player2_ip
     tracking_state["active_player_ip"] = config.active_player_ip
     tracking_state["experiment_start_time"] = time.time()
     tracking_state["samples"] = []
     
-    print(f"Started tracking: group={config.group_id}, condition={config.condition}, player={config.active_player_ip}")
+    print(f"Started tracking: group={config.group_id}, condition={config.condition}")
+    print(f"  Player1: {config.player1_ip}, Player2: {config.player2_ip}")
+    print(f"  Mimicker: {config.active_player_ip}")
     return { "status": "ok", "message": "Tracking started" }
 
 @app.post("/tracking/stop")
@@ -421,7 +443,7 @@ def download_tracking_csv():
     
     # Write header
     header = [
-        "timestamp", "elapsed_time", "group_id", "condition", "current_word", "word_time_remaining",
+        "timestamp", "elapsed_time", "player_id", "role", "group_id", "condition", "current_word", "word_time_remaining",
         "center_eye_pos_x", "center_eye_pos_y", "center_eye_pos_z",
         "center_eye_rot_w", "center_eye_rot_x", "center_eye_rot_y", "center_eye_rot_z",
         "left_hand_pos_x", "left_hand_pos_y", "left_hand_pos_z",
@@ -437,6 +459,8 @@ def download_tracking_csv():
         row = [
             str(sample["timestamp"]),
             f"{sample['elapsed_time']:.4f}",
+            sample["player_id"],
+            sample["role"],
             tracking_state["group_id"],
             tracking_state["condition"],
             sample["current_word"],