## Summary
- **Root cause**: `statsapi.mlb.com` returns 406 (deprecated). Switched MLB to ESPN's free standings API (`site.api.espn.com/apis/v2/sports/baseball/mlb/standings`), consistent with NBA, WNBA, and MLS.
- **Refactor**: Extracted a shared `espn.ts` utility module, eliminating 4× duplication of `statsMap()`, `flattenEspnStandings()`, ESPN interfaces, and the `playoffSeed` → conference rank logic across adapters.
- **Bug fixes** found during review and applied across all affected adapters:
- `parseConferenceRank`: `|| undefined` falsy-zero bug replaced with `isNaN` guard
- Sort comparators: stable alphabetical tiebreaker added to MLB, NBA, WNBA
- `winPct`: falls back to `wins/(wins+losses)` if ESPN omits the stat (was silently 0)
- statsMap pre-built once per entry before sorting in all adapters (was rebuilt per comparison)
- WNBA `parseEntry`: accepts pre-computed `sm` instead of rebuilding it internally
- MLB `gamesBack`: tests updated to reflect ESPN returns numeric `0` for division leaders (old API used `"-"` → `undefined`)
## Test plan
- [ ] All 60 standings-sync unit tests pass (`npm run test:run -- app/services/standings-sync`)
- [ ] Trigger MLB standings sync from admin panel and confirm it returns data without a 406
- [ ] Confirm NBA, WNBA, MLS syncs still work (adapters touched but behaviour unchanged)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Chris Parsons <chrisparsons1127@gmail.com>
Reviewed-on: #62
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