# Seattle physical-footprint rebuild — v0.17.0

Started October 2, 2026. This is a construction repair and a traceable prototype, not seat accuracy certification. See [STADIUM_QA.md](STADIUM_QA.md) for the required release gates.

## What changed

The old implementation treated an unfolded ticket diagram as a physical plan, assigned wall corners to fixed angular stations, and pulled raised seating inward by 30 or 72 feet. Those choices distorted the field, made neighboring sections twist and placed the Diamond Club through main-bowl rows.

The replacement uses separately registered main, club and upper floor-plan traces. Every bank has paired front/back boundaries and corner cuts. Premium seats have their own footprint, with the main bowl set behind them. Section and row labels still come from the public reference inventory. Heights and subdivisions between traced corners remain estimates.

Field registration preserves diagram bearings. Each published Statcast ray intersects the traced fence first; its distance then calibrates that bearing. Both actual corner bearings and the five calibrated stations enter the rendered fence. The exact match at five fitted controls is **not** an independent accuracy test. The posted Mariners guide's 409-foot center-field distance conflicts with the current Savant station's 401 feet; this edition retains Savant's five-station convention and records the conflict.

The bullpen walk, visitor/home bullpen surfaces, left-center Cantina and center-field batter's eye remain separate destinations. Bullpen lanes now fit a full 60.5-foot pitching distance with end clearance. Their precise footprints and heights still require overhead imagery and independent photo measurements. The cafe's building and glazing now follow its section footprint. Concourses and suite bands follow the physical deck traces; the roof remains hidden.

## Reproducible sources and traces

- [Official Mariners concourse map](https://www.mlb.com/mariners/ballpark/concourse-map), using its public Main Concourse, Club Level and Upper Bowl wayfinding views. Floor maps contain ghost geometry and do not provide surveyed seat boundaries.
- [Official section map](https://www.mlb.com/mariners/ballpark/seat-map) and the user's supplied seating diagram for section order.
- [Official ’Pen information](https://www.mlb.com/mariners/tickets/the-pen) for public-access versus bullpen destinations.
- [Photographs of the grandstand, cafe and Cantina](https://www.intheballparks.com/american/t-mobile) for visual comparison. Photo dates/renovation editions need reconciliation before a geographic pass.
- [Savant park dimensions](https://baseballsavant.mlb.com/leaderboard/statcast-park-factors?type=dimensions&year=2026) for calibration distances.

Captured source views are retained locally in `data/qa-v0.17/seattle-main-reference.jpg`, `seattle-club-reference.jpg`, `seattle-upper-reference.jpg`, `seattle-grandstand-photo.jpg` and `seattle-cantina-photo.jpg`. These research captures are not bundled into the public preview. The pixel anchors and bank boundaries are inspectable in `mariners-geometry.js`.

| Source view | Home plate | LF control | RF control |
| --- | --- | --- | --- |
| Main | 699, 428 | 717, 177 | 1040, 444 |
| Club | 714, 415 | 734, 148 | 1082, 430 |
| Upper | 687, 394 | 707, 111 | 1089, 412 |

These are manually selected wayfinding-map controls. Confirm actual foul poles against independent photographs; field markings on the wayfinding background are not survey evidence. The source overlay illustrates the traced banks and labels for review.

## Checks and remaining work

The shared viewer/reporting geometry contains 136 sections and 2,923 explicit row labels. Current construction checks find zero invalid rows, zero section intersections at matching levels/heights, zero close cross-section row pairs, and zero seating/bullpen/fan-zone footprints in fair territory. The previous Seattle mesh had 233 close-pair candidates. Field/foul-territory placement, full bullpen lane clearance and left-center Cantina placement have regression coverage.

Next, independently verify the actual foul poles, all section boundary stations, non-seat-zone outlines, tier elevations, row depth and seat-number progression. Then compare visible HR and foul impacts against held-out video. Five-foot and inch accuracy are not established. Seattle remains under review; the other parks retain their own unresolved QA gates. No manual evidence gates are marked passed by this rebuild.

Geometry edition advances to `park-v0.17-2026`. Earlier coordinate reports/drafts must be reviewed against the new edition; they are retained and do not silently move to a new section. No production fan reports have been migrated or deleted.