diff --git a/app/services/season_stats.py b/app/services/season_stats.py
index 991bfa5..bf0e06e 100644
--- a/app/services/season_stats.py
+++ b/app/services/season_stats.py
@@ -76,7 +76,8 @@ def _get_player_pairs(game_id: int) -> tuple[set, set]:
     for batter_id, batter_team_id, pitcher_id, pitcher_team_id in plays:
         if batter_id is not None:
             batting_pairs.add((batter_id, batter_team_id))
-        pitching_pairs.add((pitcher_id, pitcher_team_id))
+        if pitcher_id is not None:
+            pitching_pairs.add((pitcher_id, pitcher_team_id))
 
     # Include pitchers who have a Decision but no StratPlay rows for this game
     # (rare edge case, e.g. a pitcher credited with a decision without recording