---
phase: 04-canonical-linking
plan: 01
subsystem: data-pipeline
tags: [games, canonicalization, linking, validation]

requires:
  - phase: 03-alias-systems
    provides: Team/stadium aliases for all 7 sports

provides:
  - Canonical games with resolved team/stadium links
  - Validated game-team-stadium relationships

affects: [05-cloudkit-crud, ios-app-data]

tech-stack:
  added: []
  patterns: [game-canonicalization, link-validation, team-abbreviation-aliases]

key-files:
  created:
    - Scripts/data/games_canonical.json
    - Scripts/data/game_resolution_warnings.json
  modified:
    - Scripts/canonicalize_games.py

key-decisions:
  - Added 3 missing team abbreviation aliases discovered during canonicalization (WSH->WAS for NFL, NY->NYRB and ATX->AUS for MLS)
  - NFL playoff placeholder games (TBD/AFC/NFC) are expected warnings and do not require fixes

patterns-established:
  - Team abbreviation alias discovery during canonicalization run
  - Iterative alias refinement based on resolution warnings

issues-created: []

duration: 4 min
completed: 2026-01-10
---

# Phase 4 Plan 01: Canonical Linking Summary

**5760 games canonicalized with 100% team/stadium resolution rate (excluding 8 expected NFL playoff placeholders)**

## Performance

- Duration: ~4 minutes
- Start: 2026-01-10 09:54
- End: 2026-01-10 09:58
- Tasks completed: 3 of 3

## Accomplishments

1. **Game Canonicalization Pipeline**: Generated `games_canonical.json` with 5760 canonical games across 5 sports
   - NBA: 1230 games
   - MLB: 2430 games
   - NHL: 1312 games
   - NFL: 278 games
   - MLS: 510 games

2. **Team Alias Resolution**: Added 3 missing team abbreviation aliases to handle data source variations:
   - `('NFL', 'WSH'): 'team_nfl_was'` - Washington Commanders alternate
   - `('MLS', 'NY'): 'team_mls_nyrb'` - NY Red Bulls short form
   - `('MLS', 'ATX'): 'team_mls_aus'` - Austin FC alternate

3. **Validation**: All canonical links validated successfully
   - 0 errors, 0 warnings
   - All 5760 games have valid `home_team_canonical_id`
   - All 5760 games have valid `away_team_canonical_id`
   - All 5760 games have valid `stadium_canonical_id`
   - No `team_unknown_*` or `stadium_unknown_*` references

4. **Expected Warnings**: 8 NFL playoff placeholder games excluded (TBD/AFC/NFC teams will be updated when playoffs begin)

## Files Created/Modified

| File | Description |
|------|-------------|
| `Scripts/data/games_canonical.json` | 2.0MB - 5760 canonical games with resolved team/stadium links |
| `Scripts/data/game_resolution_warnings.json` | 8 expected NFL playoff placeholder warnings |
| `Scripts/canonicalize_games.py` | Added 3 team abbreviation aliases |

## Task Commits

| Task | Commit | Files |
|------|--------|-------|
| Task 1: Run game canonicalization | b628611 | canonicalize_games.py, games_canonical.json, game_resolution_warnings.json |
| Task 2: Validate canonical links | (validation only) | No file changes |
| Task 3: Fix resolution issues | (no issues found) | No changes needed |

## Deviations from Plan

- **Auto-fix applied**: During Task 1, discovered 3 missing team aliases (WSH, NY, ATX) that caused 85 games to fail resolution. Fixed immediately by adding aliases to TEAM_ABBREV_ALIASES and re-running canonicalization. This is consistent with Task 3's purpose but was handled proactively.

## Issues Encountered

None. All tasks completed successfully.

## Next Phase Readiness

Ready for **Phase 5: CloudKit CRUD**
- `games_canonical.json` contains 5760 games with complete team/stadium linking
- All canonical IDs resolve to valid entries
- Data validated and ready for CloudKit upload