diff --git a/command_logic/logic_gameplay.py b/command_logic/logic_gameplay.py
index ed211e8..d254ee0 100644
--- a/command_logic/logic_gameplay.py
+++ b/command_logic/logic_gameplay.py
@@ -33,6 +33,49 @@ TO_BASE = {
     3: 'to third',
     4: 'home'
 }
+
+
+def safe_wpa_lookup(inning_half: str, inning_num: int, starting_outs: int, on_base_code: int, run_diff: int) -> float:
+    """
+    Safely lookup win probability from WPA_DF with fallback logic for missing keys.
+
+    Fallback strategy:
+    1. Try exact lookup
+    2. Try with simplified on_base_code (reduce to bases empty state)
+    3. Return 0.0 if no data available
+
+    Args:
+        inning_half: 'top' or 'bot'
+        inning_num: Inning number (1-9)
+        starting_outs: Number of outs (0-2)
+        on_base_code: Base occupation code (0-7)
+        run_diff: Home run differential (-6 to 6)
+
+    Returns:
+        float: Home team win expectancy (0.0 to 1.0)
+    """
+    # Construct the primary key
+    key = f'{inning_half}_{inning_num}_{starting_outs}_out_{on_base_code}_obc_{run_diff}_home_run_diff'
+
+    # Try exact lookup first
+    try:
+        return float(WPA_DF.loc[key, 'home_win_ex'])
+    except KeyError:
+        logger.warning(f'WPA key not found: {key}, attempting fallback')
+
+    # Fallback 1: Try with simplified on_base_code (bases empty = 0)
+    if on_base_code != 0:
+        fallback_key = f'{inning_half}_{inning_num}_{starting_outs}_out_0_obc_{run_diff}_home_run_diff'
+        try:
+            result = float(WPA_DF.loc[fallback_key, 'home_win_ex'])
+            logger.info(f'WPA fallback successful using bases empty state: {fallback_key}')
+            return result
+        except KeyError:
+            logger.warning(f'WPA fallback key not found: {fallback_key}')
+
+    # Fallback 2: Return 0.0 if no data available
+    logger.warning(f'WPA using fallback value 0.0 for missing key: {key}')
+    return 0.0
 AT_BASE = {
     2: 'at second',
     3: 'at third',
@@ -503,11 +546,11 @@ def get_wpa(this_play: Play, next_play: Play):
         new_win_ex = 1.0
     else:
         inning_num = 9 if next_play.inning_num > 9 else next_play.inning_num
-        new_win_ex = WPA_DF.loc[f'{next_play.inning_half}_{inning_num}_{next_play.starting_outs}_out_{next_play.on_base_code}_obc_{new_rd}_home_run_diff'].home_win_ex
+        new_win_ex = safe_wpa_lookup(next_play.inning_half, inning_num, next_play.starting_outs, next_play.on_base_code, new_rd)
         # print(f'new_win_ex = {new_win_ex}')
 
     inning_num = 9 if this_play.inning_num > 9 else this_play.inning_num
-    old_win_ex = WPA_DF.loc[f'{this_play.inning_half}_{inning_num}_{this_play.starting_outs}_out_{this_play.on_base_code}_obc_{old_rd}_home_run_diff'].home_win_ex
+    old_win_ex = safe_wpa_lookup(this_play.inning_half, inning_num, this_play.starting_outs, this_play.on_base_code, old_rd)
     # print(f'old_win_ex = {old_win_ex}')
 
     wpa = float(round(new_win_ex - old_win_ex, 3))
diff --git a/tests/command_logic/test_logic_gameplay.py b/tests/command_logic/test_logic_gameplay.py
index 6a6a97f..9a06fb7 100644
--- a/tests/command_logic/test_logic_gameplay.py
+++ b/tests/command_logic/test_logic_gameplay.py
@@ -1,7 +1,7 @@
 import pytest
 from sqlmodel import Session, select, func
 
-from command_logic.logic_gameplay import advance_runners, doubles, gb_result_1, get_obc, get_re24, get_wpa, complete_play, log_run_scored, strikeouts, steals, xchecks, walks, popouts, hit_by_pitch, homeruns, singles, triples, bunts, chaos
+from command_logic.logic_gameplay import advance_runners, doubles, gb_result_1, get_obc, get_re24, get_wpa, complete_play, log_run_scored, strikeouts, steals, xchecks, walks, popouts, hit_by_pitch, homeruns, singles, triples, bunts, chaos, safe_wpa_lookup
 from in_game.gameplay_models import Lineup, Play
 from tests.factory import session_fixture, Game
 
@@ -83,6 +83,32 @@ def test_get_wpa(session: Session):
     assert get_wpa(this_play, next_play) == 0.153
 
 
+def test_safe_wpa_lookup():
+    """Test safe_wpa_lookup handles both valid and missing keys gracefully."""
+    # Test 1: Valid key should return actual value
+    valid_result = safe_wpa_lookup('bot', 1, 0, 0, 0)
+    assert isinstance(valid_result, float)
+    assert 0.0 <= valid_result <= 1.0
+    assert valid_result == 0.589  # Known value from wpa_data.csv
+
+    # Test 2: Missing key with bases loaded should fallback to bases empty
+    # This simulates the error case: top_1_0_out_6_obc_-5_home_run_diff doesn't exist
+    fallback_result = safe_wpa_lookup('top', 1, 0, 6, -5)
+    assert isinstance(fallback_result, float)
+    assert 0.0 <= fallback_result <= 1.0
+    # Should use fallback to bases empty state if available
+
+    # Test 3: If even bases empty fallback doesn't exist, should return 0.0
+    # (This is an edge case that shouldn't happen with complete data)
+    extreme_fallback = safe_wpa_lookup('top', 1, 0, 7, -10)  # Invalid obc and extreme run diff
+    assert extreme_fallback == 0.0
+
+    # Test 4: Another valid key
+    valid_result_2 = safe_wpa_lookup('top', 9, 2, 3, 1)
+    assert isinstance(valid_result_2, float)
+    assert 0.0 <= valid_result_2 <= 1.0
+
+
 def test_complete_play(session: Session):
     game_1 = session.get(Game, 1)
     this_play = game_1.current_play_or_none(session)