Interactive Tool
BCR Coverage Surface
The viewer renders the coverage surface from the paper in three dimensions: drawdown depth and duration on the horizontal axes, required starting BCR on the vertical axis, with the four backtested regimes marked at their empirical values. Dark theme by default, with a light/dark toggle in the viewer's header. Drag to rotate, pinch to zoom, save a PNG from the camera icon.
Provenance and verification
The viewer embedded above is True North's build. It renders the same
surface as the author's original artifact: the grid and the four regime anchors are
derived at build time from outputs/surface_grid.csv and
outputs/regime_descriptors.csv in Jackson Fairbanks's MIT-licensed
repository,
and the build asserts on every deploy that the derived values are identical to the
data inside the author's hashed artifact. The theming and page chrome are ours; the
surface, the regime markers, and the green-to-red coverage scale are the author's
data, unchanged.
The author's original artifact remains hosted on this site
at its raw URL,
byte-identical, for anyone verifying the published hash — its SHA-256 is pinned in
verify.sh at repository release v1.0.0 and in the Zenodo archive
(DOI 10.5281/zenodo.21840694):
31804efe2c6f1b987dbcd3ea210610aa76db6ede067410d5105d16c77720a4e3 bcr_3d_viewer.html
To check it yourself (-L matters: the platform 308-redirects the
.html URL to its extensionless form, and without it you hash an empty body):
curl -sL https://tnorth.com/tools/bcr-coverage-surface/bcr_3d_viewer.html | shasum -a 256