gWAR Schema: League Constants and Component Fields

[grovecj]

Overview

Add database schema to support Grove WAR (gWAR) calculation, including league constants table and component fields on stats tables.

Parent Issue

Part of #94 (WAR and Advanced Stats)

Schema Changes

New Table: league_constants

Stores yearly league-wide values needed for gWAR calculations:

CREATE TABLE league_constants (
    id BIGSERIAL PRIMARY KEY,
    season INTEGER NOT NULL UNIQUE,
    lg_woba DECIMAL(5,4) NOT NULL,        -- League wOBA (~0.310-0.320)
    woba_scale DECIMAL(5,4) NOT NULL,      -- wOBA scale factor (~1.15-1.25)
    lg_r_per_pa DECIMAL(6,5) NOT NULL,     -- League R/PA for replacement
    fip_constant DECIMAL(4,2) NOT NULL,    -- FIP constant (~3.10-3.20)
    runs_per_win DECIMAL(4,2) DEFAULT 10.0,
    created_at TIMESTAMP DEFAULT NOW()
);

New Columns: player_batting_stats

ALTER TABLE player_batting_stats ADD COLUMN gwar DECIMAL(4,1);
ALTER TABLE player_batting_stats ADD COLUMN gwar_batting DECIMAL(5,1);
ALTER TABLE player_batting_stats ADD COLUMN gwar_baserunning DECIMAL(5,1);
ALTER TABLE player_batting_stats ADD COLUMN gwar_fielding DECIMAL(5,1);
ALTER TABLE player_batting_stats ADD COLUMN gwar_positional DECIMAL(5,1);
ALTER TABLE player_batting_stats ADD COLUMN gwar_replacement DECIMAL(5,1);
ALTER TABLE player_batting_stats ADD COLUMN oaa INTEGER;

New Columns: player_pitching_stats

ALTER TABLE player_pitching_stats ADD COLUMN gwar DECIMAL(4,1);
ALTER TABLE player_pitching_stats ADD COLUMN gwar_pitching DECIMAL(5,1);
ALTER TABLE player_pitching_stats ADD COLUMN gwar_replacement DECIMAL(5,1);

Entities to Update

• PlayerBattingStats.java - Add gWAR component fields
• PlayerPitchingStats.java - Add gWAR fields

New Entities

• LeagueConstants.java - Entity for league constants
• LeagueConstantsRepository.java - Repository

Acceptance Criteria

• V14 migration applies cleanly on PostgreSQL
• V14 migration applies on H2 (tests)
• League constants seeded for 2022-2024
• Entity fields mapped correctly
• Leaderboard indexes created for gwar columns

Dependencies

• Depends on Schema: Advanced Sabermetric Statistics #123 (Advanced Sabermetrics Schema) being complete