CLAUDE: Add configurable regulation_innings and outs_per_inning

Issue #8 from code review - hardcoded inning limit (9) and outs (3)
prevented custom game modes like 7-inning doubleheaders.

Changes:
- Added regulation_innings: int = 9 to GameState (default standard)
- Added outs_per_inning: int = 3 to GameState (default standard)
- Updated validators.py: is_game_over(), can_continue_inning(), shallow outfield
- Updated game_models.py: is_game_over() uses state.regulation_innings
- Updated game_engine.py: _finalize_play() uses state.outs_per_inning

Now supports custom game modes:
- 7-inning doubleheaders
- 6-inning youth/minor league games
- Alternative out rules (2-out innings, etc.)

All 739 unit tests passing.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/.claude/CODE_REVIEW_GAME_ENGINE.md

@@ -295,9 +295,12 @@ Some methods seem designed for testing but are public API.
   - Validation exists in validators.py: hold_runners validates against occupied bases (lines 71-77)
   - Validation exists in validators.py: steal_attempts validates against runner state (lines 156-165)
   - Validators called in submit_defensive_decision (line 225) and submit_offensive_decision (line 263)
-- [x] High issue #8 deferred to next sprint (2025-11-19)
-  - Hardcoded inning limit (9) used in validators.py and game_models.py
-  - Requires config system changes - appropriate for technical debt phase
+- [x] High issue #8 fixed (2025-11-19)
+  - Added `regulation_innings: int = 9` and `outs_per_inning: int = 3` to GameState
+  - Updated validators.py: `is_game_over()`, `can_continue_inning()`, shallow outfield check
+  - Updated game_models.py: `is_game_over()` method
+  - Updated game_engine.py: `_finalize_play()` inning change checks
+  - Now supports 7-inning doubleheaders, 6-inning youth games, etc.
 - [x] High issue #9 already fixed (part of Issue #3)
   - `_cleanup_game_resources()` called in `end_game()` at line 1109
 - [x] High issue #10 acknowledged (2025-11-19)

backend/app/core/game_engine.py

@@ -474,7 +474,7 @@ class GameEngine:
                     logger.debug("Skipped game state update - no changes to persist")
 
                 # Check for inning change
-                if state.outs >= 3:
+                if state.outs >= state.outs_per_inning:
                     await self._advance_inning(state, game_id)
                     # Update DB again after inning change
                     await self.db_ops.update_game_state(
@@ -497,7 +497,7 @@ class GameEngine:
                 raise
 
         # Batch save rolls at half-inning boundary (separate transaction - audit data)
-        if state.outs >= 3:
+        if state.outs >= state.outs_per_inning:
             await self._batch_save_inning_rolls(game_id)
 
         # Prepare next play or clean up if game completed

backend/app/core/validators.py

@@ -85,11 +85,11 @@ class GameValidator:
         if decision.outfield_depth == 'shallow':
             # Walk-off conditions:
             # 1. Home team batting (bottom of inning)
-            # 2. Bottom of 9th or later
+            # 2. Bottom of final inning or later
             # 3. Tied or trailing
             # 4. Runner on base
             is_home_batting = (state.half == 'bottom')
-            is_late_inning = (state.inning >= 9)
+            is_late_inning = (state.inning >= state.regulation_innings)
 
             if is_home_batting:
                 is_close_game = (state.home_score <= state.away_score)
@@ -100,8 +100,8 @@ class GameValidator:
 
             if not (is_home_batting and is_late_inning and is_close_game and has_runners):
                 raise ValidationError(
-                    "Shallow outfield only allowed in walk-off situations "
-                    "(home team batting, bottom 9th+ inning, tied/trailing, runner on base)"
+                    f"Shallow outfield only allowed in walk-off situations "
+                    f"(home team batting, bottom {state.regulation_innings}th+ inning, tied/trailing, runner on base)"
                 )
 
         logger.debug("Defensive decision validated")
@@ -202,21 +202,23 @@ class GameValidator:
 
     @staticmethod
     def can_continue_inning(state: GameState) -> bool:
-        """Check if inning can continue"""
-        return state.outs < 3
+        """Check if inning can continue using state's outs_per_inning"""
+        return state.outs < state.outs_per_inning
 
     @staticmethod
     def is_game_over(state: GameState) -> bool:
-        """Check if game is complete"""
-        # Game over after 9 innings if score not tied
-        if state.inning >= 9 and state.half == "bottom":
+        """Check if game is complete using state's regulation_innings"""
+        reg = state.regulation_innings
+
+        # Game over after regulation innings if score not tied
+        if state.inning >= reg and state.half == "bottom":
             if state.home_score != state.away_score:
                 return True
-            # Home team wins if ahead in bottom of 9th
+            # Home team wins if ahead in bottom of final inning
             if state.home_score > state.away_score:
                 return True
         # Also check if we're in extras and bottom team is ahead
-        if state.inning > 9 and state.half == "bottom":
+        if state.inning > reg and state.half == "bottom":
             if state.home_score > state.away_score:
                 return True
         return False

backend/app/models/game_models.py

@@ -374,6 +374,10 @@ class GameState(BaseModel):
     # Resolution mode
     auto_mode: bool = False  # True = auto-generate outcomes (PD only), False = manual submissions
 
+    # Game rules (configurable per game)
+    regulation_innings: int = Field(default=9, ge=1)  # Standard 9, doubleheader 7, etc.
+    outs_per_inning: int = Field(default=3, ge=1)  # Standard 3
+
     # Game state
     status: str = "pending"  # pending, active, paused, completed
     inning: int = Field(default=1, ge=1)
@@ -646,24 +650,27 @@ class GameState(BaseModel):
         """
         Check if game is over.
 
-        Game ends after 9 innings if home team is ahead or tied,
-        or immediately if home team takes lead in bottom of 9th or later.
+        Game ends after regulation innings if home team is ahead or tied,
+        or immediately if home team takes lead in bottom of final inning or later.
+        Uses self.regulation_innings (default 9) for game length.
         """
-        if self.inning < 9:
+        reg = self.regulation_innings
+
+        if self.inning < reg:
             return False
 
-        if self.inning == 9 and self.half == "bottom":
-            # Bottom of 9th - game ends if home team ahead
+        if self.inning == reg and self.half == "bottom":
+            # Bottom of final regulation inning - game ends if home team ahead
             if self.home_score > self.away_score:
                 return True
 
-        if self.inning > 9 and self.half == "bottom":
+        if self.inning > reg and self.half == "bottom":
             # Extra innings, bottom half - walk-off possible
             if self.home_score > self.away_score:
                 return True
 
-        if self.inning >= 9 and self.half == "top" and self.outs >= 3:
-            # Top of 9th or later just ended
+        if self.inning >= reg and self.half == "top" and self.outs >= self.outs_per_inning:
+            # Top of final inning or later just ended
             if self.home_score != self.away_score:
                 return True