diff --git a/backend/clean_test_data.py b/backend/clean_test_data.py
new file mode 100644
index 0000000..77cf9a1
--- /dev/null
+++ b/backend/clean_test_data.py
@@ -0,0 +1,308 @@
+#!/usr/bin/env python3
+"""
+Database Cleanup Script
+
+Clear out test data from database tables.
+Use with caution - this will DELETE data!
+
+Usage:
+    python clean_test_data.py              # Interactive mode
+    python clean_test_data.py --all        # Delete all data
+    python clean_test_data.py --game <id>  # Delete specific game
+"""
+
+import asyncio
+import logging
+import sys
+from uuid import UUID
+from sqlalchemy import select, delete
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database.session import AsyncSessionLocal
+from app.models.db_models import (
+    Game,
+    Play,
+    Lineup,
+    GameSession,
+    RosterLink,
+    GameCardsetLink
+)
+
+# Setup logging
+logging.basicConfig(
+    level=logging.INFO,
+    format='%(asctime)s - %(levelname)s - %(message)s'
+)
+logger = logging.getLogger(__name__)
+
+
+class DatabaseCleaner:
+    """Clean test data from database."""
+
+    async def count_records(self, session: AsyncSession) -> dict:
+        """Count records in each table."""
+        counts = {}
+
+        # Count games
+        result = await session.execute(select(Game))
+        counts['games'] = len(list(result.scalars().all()))
+
+        # Count plays
+        result = await session.execute(select(Play))
+        counts['plays'] = len(list(result.scalars().all()))
+
+        # Count lineups
+        result = await session.execute(select(Lineup))
+        counts['lineups'] = len(list(result.scalars().all()))
+
+        # Count roster links
+        result = await session.execute(select(RosterLink))
+        counts['roster_links'] = len(list(result.scalars().all()))
+
+        # Count game sessions
+        result = await session.execute(select(GameSession))
+        counts['game_sessions'] = len(list(result.scalars().all()))
+
+        # Count cardset links
+        result = await session.execute(select(GameCardsetLink))
+        counts['game_cardset_links'] = len(list(result.scalars().all()))
+
+        return counts
+
+    async def delete_game(self, game_id: UUID) -> None:
+        """
+        Delete a specific game and all related data.
+
+        Cascade deletes will automatically remove:
+        - Plays
+        - Lineups
+        - RosterLinks
+        - GameSession
+        - GameCardsetLinks
+        """
+        async with AsyncSessionLocal() as session:
+            try:
+                # Check if game exists
+                result = await session.execute(
+                    select(Game).where(Game.id == game_id)
+                )
+                game = result.scalar_one_or_none()
+
+                if not game:
+                    logger.warning(f"Game {game_id} not found")
+                    return
+
+                logger.info(f"Deleting game {game_id} ({game.league_id})...")
+
+                # Delete game (cascade will handle related records)
+                await session.delete(game)
+                await session.commit()
+
+                logger.info(f"✅ Successfully deleted game {game_id}")
+
+            except Exception as e:
+                await session.rollback()
+                logger.error(f"❌ Error deleting game: {e}", exc_info=True)
+                raise
+
+    async def delete_all(self, confirm: bool = False) -> None:
+        """
+        Delete ALL data from all tables.
+
+        WARNING: This is destructive and cannot be undone!
+        """
+        if not confirm:
+            logger.warning("⚠️  delete_all() requires confirm=True parameter")
+            return
+
+        async with AsyncSessionLocal() as session:
+            try:
+                logger.info("🗑️  Deleting ALL data from database...")
+
+                # Get counts before deletion
+                before_counts = await self.count_records(session)
+                logger.info(f"Current record counts: {before_counts}")
+
+                # Delete in correct order (children first)
+                logger.info("Deleting plays...")
+                await session.execute(delete(Play))
+
+                logger.info("Deleting lineups...")
+                await session.execute(delete(Lineup))
+
+                logger.info("Deleting roster links...")
+                await session.execute(delete(RosterLink))
+
+                logger.info("Deleting game sessions...")
+                await session.execute(delete(GameSession))
+
+                logger.info("Deleting game cardset links...")
+                await session.execute(delete(GameCardsetLink))
+
+                logger.info("Deleting games...")
+                await session.execute(delete(Game))
+
+                await session.commit()
+
+                # Verify deletion
+                after_counts = await self.count_records(session)
+                logger.info(f"After deletion: {after_counts}")
+
+                logger.info("✅ Successfully deleted all data")
+
+            except Exception as e:
+                await session.rollback()
+                logger.error(f"❌ Error deleting data: {e}", exc_info=True)
+                raise
+
+    async def list_games(self) -> None:
+        """List all games in the database."""
+        async with AsyncSessionLocal() as session:
+            result = await session.execute(
+                select(Game).order_by(Game.created_at.desc())
+            )
+            games = result.scalars().all()
+
+            if not games:
+                logger.info("No games found in database")
+                return
+
+            logger.info(f"\n{'='*80}")
+            logger.info(f"Found {len(games)} game(s) in database:")
+            logger.info(f"{'='*80}")
+
+            for game in games:
+                logger.info(f"\nGame ID: {game.id}")
+                logger.info(f"  League: {game.league_id}")
+                logger.info(f"  Status: {game.status}")
+                logger.info(f"  Mode: {game.game_mode}")
+                logger.info(f"  Teams: {game.away_team_id} @ {game.home_team_id}")
+                logger.info(f"  Score: {game.away_score}-{game.home_score}")
+                if game.current_inning:
+                    logger.info(f"  State: {game.current_half} {game.current_inning}")
+                logger.info(f"  AI: Home={game.home_team_is_ai}, Away={game.away_team_is_ai}")
+                logger.info(f"  Created: {game.created_at}")
+
+    async def show_stats(self) -> None:
+        """Show database statistics."""
+        async with AsyncSessionLocal() as session:
+            counts = await self.count_records(session)
+
+            logger.info(f"\n{'='*80}")
+            logger.info("DATABASE STATISTICS")
+            logger.info(f"{'='*80}")
+            logger.info(f"Games:            {counts['games']:>6}")
+            logger.info(f"Plays:            {counts['plays']:>6}")
+            logger.info(f"Lineups:          {counts['lineups']:>6}")
+            logger.info(f"Roster Links:     {counts['roster_links']:>6}")
+            logger.info(f"Game Sessions:    {counts['game_sessions']:>6}")
+            logger.info(f"Cardset Links:    {counts['game_cardset_links']:>6}")
+            logger.info(f"{'='*80}\n")
+
+
+async def interactive_menu():
+    """Interactive menu for cleanup operations."""
+    cleaner = DatabaseCleaner()
+
+    while True:
+        print("\n" + "="*60)
+        print("DATABASE CLEANUP MENU")
+        print("="*60)
+        print("1. Show database statistics")
+        print("2. List all games")
+        print("3. Delete specific game")
+        print("4. Delete ALL data (⚠️  DANGER)")
+        print("5. Exit")
+        print("="*60)
+
+        choice = input("\nEnter your choice (1-5): ").strip()
+
+        if choice == "1":
+            await cleaner.show_stats()
+
+        elif choice == "2":
+            await cleaner.list_games()
+
+        elif choice == "3":
+            game_id_str = input("Enter game UUID: ").strip()
+            try:
+                game_id = UUID(game_id_str)
+                confirm = input(f"Delete game {game_id}? (yes/no): ").strip().lower()
+                if confirm == "yes":
+                    await cleaner.delete_game(game_id)
+                else:
+                    logger.info("Cancelled")
+            except ValueError:
+                logger.error("Invalid UUID format")
+
+        elif choice == "4":
+            await cleaner.show_stats()
+            print("\n⚠️  WARNING: This will DELETE ALL DATA from the database!")
+            confirm1 = input("Are you absolutely sure? (type 'DELETE ALL'): ").strip()
+            if confirm1 == "DELETE ALL":
+                confirm2 = input("Type 'yes' to confirm: ").strip().lower()
+                if confirm2 == "yes":
+                    await cleaner.delete_all(confirm=True)
+                else:
+                    logger.info("Cancelled")
+            else:
+                logger.info("Cancelled")
+
+        elif choice == "5":
+            logger.info("Exiting...")
+            break
+
+        else:
+            logger.warning("Invalid choice")
+
+
+async def main():
+    """Main entry point."""
+    cleaner = DatabaseCleaner()
+
+    # Parse command line arguments
+    if len(sys.argv) == 1:
+        # No arguments - run interactive mode
+        await interactive_menu()
+
+    elif "--help" in sys.argv or "-h" in sys.argv:
+        print(__doc__)
+
+    elif "--stats" in sys.argv:
+        await cleaner.show_stats()
+
+    elif "--list" in sys.argv:
+        await cleaner.list_games()
+
+    elif "--all" in sys.argv:
+        await cleaner.show_stats()
+        print("\n⚠️  WARNING: This will DELETE ALL DATA!")
+        confirm = input("Type 'yes' to confirm: ").strip().lower()
+        if confirm == "yes":
+            await cleaner.delete_all(confirm=True)
+        else:
+            logger.info("Cancelled")
+
+    elif "--game" in sys.argv:
+        idx = sys.argv.index("--game")
+        if idx + 1 < len(sys.argv):
+            try:
+                game_id = UUID(sys.argv[idx + 1])
+                await cleaner.delete_game(game_id)
+            except ValueError:
+                logger.error("Invalid UUID format")
+        else:
+            logger.error("--game requires a UUID argument")
+
+    else:
+        print("Unknown arguments. Use --help for usage information.")
+
+
+if __name__ == "__main__":
+    try:
+        asyncio.run(main())
+    except KeyboardInterrupt:
+        logger.info("\nInterrupted by user")
+    except Exception as e:
+        logger.error(f"Error: {e}", exc_info=True)
+        sys.exit(1)
diff --git a/backend/test_db_playground.py b/backend/test_db_playground.py
new file mode 100644
index 0000000..50a18a1
--- /dev/null
+++ b/backend/test_db_playground.py
@@ -0,0 +1,298 @@
+#!/usr/bin/env python3
+"""
+Interactive Database Playground
+
+Test and experiment with database models and operations.
+Run this script to create test games and explore the database operations.
+
+Usage:
+    python test_db_playground.py
+"""
+
+import asyncio
+import logging
+from uuid import uuid4, UUID
+from typing import Optional
+
+from app.database.operations import DatabaseOperations
+from app.models.roster_models import PdRosterLinkData, SbaRosterLinkData
+
+# Setup logging
+logging.basicConfig(
+    level=logging.INFO,
+    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+)
+logger = logging.getLogger(__name__)
+
+
+class DatabasePlayground:
+    """Interactive playground for testing database operations."""
+
+    def __init__(self):
+        self.db_ops = DatabaseOperations()
+        self.test_game_id: Optional[UUID] = None
+
+    async def demo_pd_game(self):
+        """Create and populate a PD league game with roster and lineup."""
+        logger.info("=" * 60)
+        logger.info("DEMO: Creating PD League Game")
+        logger.info("=" * 60)
+
+        # Create game
+        self.test_game_id = uuid4()
+        game = await self.db_ops.create_game(
+            game_id=self.test_game_id,
+            league_id="pd",
+            home_team_id=1,
+            away_team_id=2,
+            game_mode="friendly",
+            visibility="public",
+            home_team_is_ai=False,
+            away_team_is_ai=True,
+            ai_difficulty="balanced"
+        )
+        logger.info(f"✅ Created PD game: {game.id}")
+        logger.info(f"   Home Team: {game.home_team_id} (Human)")
+        logger.info(f"   Away Team: {game.away_team_id} (AI - {game.ai_difficulty})")
+
+        # Add cards to roster
+        logger.info("\n📋 Adding cards to roster...")
+        home_cards = [101, 102, 103, 104, 105, 106, 107, 108, 109]
+        away_cards = [201, 202, 203, 204, 205, 206, 207, 208, 209]
+
+        for card_id in home_cards:
+            roster_link = await self.db_ops.add_pd_roster_card(
+                game_id=self.test_game_id,
+                card_id=card_id,
+                team_id=1
+            )
+            logger.info(f"   Added card {card_id} to home roster (link_id={roster_link.id})")
+
+        for card_id in away_cards:
+            roster_link = await self.db_ops.add_pd_roster_card(
+                game_id=self.test_game_id,
+                card_id=card_id,
+                team_id=2
+            )
+            logger.info(f"   Added card {card_id} to away roster (link_id={roster_link.id})")
+
+        # Get roster
+        home_roster = await self.db_ops.get_pd_roster(self.test_game_id, team_id=1)
+        away_roster = await self.db_ops.get_pd_roster(self.test_game_id, team_id=2)
+        logger.info(f"\n✅ Home roster: {len(home_roster)} cards")
+        logger.info(f"✅ Away roster: {len(away_roster)} cards")
+
+        # Set lineup
+        logger.info("\n⚾ Setting starting lineup...")
+        positions = ['P', 'C', '1B', '2B', '3B', 'SS', 'LF', 'CF', 'RF']
+
+        for i, (card_id, position) in enumerate(zip(home_cards, positions), start=1):
+            lineup = await self.db_ops.add_pd_lineup_card(
+                game_id=self.test_game_id,
+                team_id=1,
+                card_id=card_id,
+                position=position,
+                batting_order=i if position != 'P' else None,
+                is_starter=True
+            )
+            logger.info(f"   {position}: Card {card_id} (batting {lineup.batting_order or 'N/A'})")
+
+        # Get active lineup
+        home_lineup = await self.db_ops.get_active_lineup(self.test_game_id, team_id=1)
+        logger.info(f"\n✅ Active lineup: {len(home_lineup)} players")
+
+        # Update game state
+        logger.info("\n🎮 Simulating game progress...")
+        await self.db_ops.update_game_state(
+            game_id=self.test_game_id,
+            inning=3,
+            half="bottom",
+            home_score=2,
+            away_score=1,
+            status="active"
+        )
+        logger.info("   Updated to: Bottom 3rd, Home 2 - Away 1")
+
+        # Save a play
+        play_data = {
+            'game_id': self.test_game_id,
+            'play_number': 1,
+            'inning': 3,
+            'half': 'bottom',
+            'outs_before': 1,
+            'batting_order': 3,
+            'away_score': 1,
+            'home_score': 2,
+            'batter_id': home_lineup[2].id,
+            'pitcher_id': home_lineup[0].id,
+            'catcher_id': home_lineup[1].id,
+            'dice_roll': '14+6',
+            'hit_type': 'FB',
+            'result_description': 'Deep fly ball to center field - Home Run!',
+            'outs_recorded': 0,
+            'runs_scored': 1,
+            'pa': 1,
+            'ab': 1,
+            'hit': 1,
+            'homerun': 1,
+            'rbi': 1,
+            'is_go_ahead': False,
+            'complete': True,
+            'locked': False
+        }
+
+        play = await self.db_ops.save_play(play_data)
+        logger.info(f"\n⚾ Saved play #{play.play_number}: {play.result_description}")
+
+        # Load game state
+        logger.info("\n🔄 Loading complete game state...")
+        game_state = await self.db_ops.load_game_state(self.test_game_id)
+        if game_state:
+            logger.info(f"✅ Loaded game state:")
+            logger.info(f"   Status: {game_state['game']['status']}")
+            logger.info(f"   Score: {game_state['game']['away_score']}-{game_state['game']['home_score']}")
+            logger.info(f"   Lineups: {len(game_state['lineups'])} players")
+            logger.info(f"   Plays: {len(game_state['plays'])} plays recorded")
+
+        return self.test_game_id
+
+    async def demo_sba_game(self):
+        """Create and populate an SBA league game with roster and lineup."""
+        logger.info("\n" + "=" * 60)
+        logger.info("DEMO: Creating SBA League Game")
+        logger.info("=" * 60)
+
+        # Create game
+        game_id = uuid4()
+        game = await self.db_ops.create_game(
+            game_id=game_id,
+            league_id="sba",
+            home_team_id=10,
+            away_team_id=11,
+            game_mode="ranked",
+            visibility="public",
+            home_team_is_ai=False,
+            away_team_is_ai=False
+        )
+        logger.info(f"✅ Created SBA game: {game.id}")
+        logger.info(f"   Home Team: {game.home_team_id}")
+        logger.info(f"   Away Team: {game.away_team_id}")
+        logger.info(f"   Mode: {game.game_mode}")
+
+        # Add players to roster
+        logger.info("\n📋 Adding players to roster...")
+        home_players = [501, 502, 503, 504, 505, 506, 507, 508, 509]
+        away_players = [601, 602, 603, 604, 605, 606, 607, 608, 609]
+
+        for player_id in home_players:
+            roster_link = await self.db_ops.add_sba_roster_player(
+                game_id=game_id,
+                player_id=player_id,
+                team_id=10
+            )
+            logger.info(f"   Added player {player_id} to home roster (link_id={roster_link.id})")
+
+        for player_id in away_players:
+            roster_link = await self.db_ops.add_sba_roster_player(
+                game_id=game_id,
+                player_id=player_id,
+                team_id=11
+            )
+            logger.info(f"   Added player {player_id} to away roster (link_id={roster_link.id})")
+
+        # Get roster
+        home_roster = await self.db_ops.get_sba_roster(game_id, team_id=10)
+        away_roster = await self.db_ops.get_sba_roster(game_id, team_id=11)
+        logger.info(f"\n✅ Home roster: {len(home_roster)} players")
+        logger.info(f"✅ Away roster: {len(away_roster)} players")
+
+        # Set lineup
+        logger.info("\n⚾ Setting starting lineup...")
+        positions = ['P', 'C', '1B', '2B', '3B', 'SS', 'LF', 'CF', 'RF']
+
+        for i, (player_id, position) in enumerate(zip(home_players, positions), start=1):
+            lineup = await self.db_ops.add_sba_lineup_player(
+                game_id=game_id,
+                team_id=10,
+                player_id=player_id,
+                position=position,
+                batting_order=i if position != 'P' else None,
+                is_starter=True
+            )
+            logger.info(f"   {position}: Player {player_id} (batting {lineup.batting_order or 'N/A'})")
+
+        # Create game session
+        session = await self.db_ops.create_game_session(game_id)
+        logger.info(f"\n✅ Created game session for game: {session.game_id}")
+
+        # Update session snapshot
+        await self.db_ops.update_session_snapshot(
+            game_id=game_id,
+            state_snapshot={'test': 'data', 'connected_users': ['user1', 'user2']}
+        )
+        logger.info("✅ Updated session snapshot")
+
+        return game_id
+
+    async def demo_cleanup(self):
+        """Demonstrate querying capabilities."""
+        if not self.test_game_id:
+            logger.warning("No test game created yet")
+            return
+
+        logger.info("\n" + "=" * 60)
+        logger.info("DEMO: Query Capabilities")
+        logger.info("=" * 60)
+
+        # Get game
+        game = await self.db_ops.get_game(self.test_game_id)
+        if game:
+            logger.info(f"\n📊 Game Details:")
+            logger.info(f"   ID: {game.id}")
+            logger.info(f"   League: {game.league_id}")
+            logger.info(f"   Status: {game.status}")
+            logger.info(f"   Inning: {game.current_half} {game.current_inning}")
+            logger.info(f"   Score: {game.away_score}-{game.home_score}")
+
+        # Get plays
+        plays = await self.db_ops.get_plays(self.test_game_id)
+        logger.info(f"\n⚾ Plays: {len(plays)} total")
+        for play in plays:
+            logger.info(f"   Play #{play.play_number}: {play.result_description}")
+
+        # Get active lineup
+        home_lineup = await self.db_ops.get_active_lineup(self.test_game_id, team_id=1)
+        logger.info(f"\n👥 Active Lineup: {len(home_lineup)} players")
+        for player in sorted(home_lineup, key=lambda x: x.batting_order or 99):
+            logger.info(f"   {player.position}: Card {player.card_id} (batting {player.batting_order or 'N/A'})")
+
+
+async def main():
+    """Run interactive playground demos."""
+    playground = DatabasePlayground()
+
+    try:
+        # Run PD game demo
+        pd_game_id = await playground.demo_pd_game()
+
+        # Run SBA game demo
+        sba_game_id = await playground.demo_sba_game()
+
+        # Show query capabilities
+        await playground.demo_cleanup()
+
+        logger.info("\n" + "=" * 60)
+        logger.info("✅ ALL DEMOS COMPLETED SUCCESSFULLY!")
+        logger.info("=" * 60)
+        logger.info(f"\nCreated games:")
+        logger.info(f"  PD Game:  {pd_game_id}")
+        logger.info(f"  SBA Game: {sba_game_id}")
+        logger.info("\nYou can query these games in the database to explore the data!")
+
+    except Exception as e:
+        logger.error(f"\n❌ Error during demo: {e}", exc_info=True)
+        raise
+
+
+if __name__ == "__main__":
+    asyncio.run(main())