Tournament Atlas — data attribution and transformations

The current selector uses 37 complete opening probability fields and app-generated daily reconstructions. Exact source URLs, dates, published values and mapped teams are retained in data-inputs/opening-sources.json in the public source repository. Year JSON files include selected-source URLs and adjustment diagnostics. Reconstructed updates are not official publisher updates. Partial and late-only inputs are excluded.

FiveThirtyEight: original men's and women's NCAA forecast CSVs, 2016–2019 and 2021–2023, recovered from the Internet Archive. Data licensed under Creative Commons Attribution 4.0 International as stated at https://github.com/fivethirtyeight/data/blob/master/README.md . License: https://creativecommons.org/licenses/by/4.0/ and adjacent LICENSE-fivethirtyeight-data.txt. Original archived probabilities and digests remain in each year's forecasts field. Changes: competition split, JSON conversion, historical ID/name corrections, and new forecastOptions generated by fitting opening marginals and conditioning on results. Later reconstructed snapshots must not be attributed to FiveThirtyEight as published forecasts.

Ken Pomeroy: public pre-tournament advancement tables, men 2016–2019 and 2021–2026, at https://kenpom.com/blog/ and exact article links in each source record. Bart Torvik: public tournament advancement tables, men 2018–2019 and 2021–2026 and women 2025–2026, from https://barttorvik.com/tourneytime.php and the corresponding women's site/archive links retained per record. Men's 2024 uses the actual March 18 archived opening table. Undated Pre-Tourney selections are labeled as such, with a reference date before play rather than an invented publication timestamp.

ESPN BPI: the complete men's 2017 opening advancement table, archived from ESPN. numberFire / Brandon Gdula: the complete men's 2025 opening table, with its article link retained. Silver Bulletin: publicly recovered women's 2024 opening table only, with its original link retained. No paid men's spreadsheet is included. Only probability facts and attribution are bundled, not articles, publisher images, logos or source code. No formal open-data license is claimed for these providers; FiveThirtyEight's CC license does not extend to them.

Transformations: printed <x% values use half the bound for fitting; zeros receive a tiny positive floor; missing First Four odds are inferred from Round-of-32 shares; rounded node totals are reconciled to a coherent bracket. Silver's LSU/UCLA half-region totals 100.7% for the Elite Eight, requiring normalization (largest change about 0.359 percentage point). Source-specific fit errors are visible in the app. The inverse matchup model is not uniquely identified by the published marginals. The public source repository documents the maximum-entropy fit, exact conditional propagation, arithmetic average and strictly prior-season logistic ensemble in data-preparation/SOURCE-MODEL.md.

Earlier Bart Torvik evidence retained in original fields: pre-tournament T-Rank Time Machine ratings dated 2024-03-18, 2025-03-17 and 2026-03-16. Sources: https://barttorvik.com/timemachine/team_results/YYYYMMDD_team_results.json.gz . Archive guidance: https://adamcwisports.blogspot.com/p/data.html . Model explanation: https://adamcwisports.blogspot.com/p/every-possession-counts.html . Those original log5 reconstructions remain separate from the current advancement-table source options.

Recorded results: ESPN historical tournament facts (teams, seeds, regions, dates, scores, winners, status), both competitions, 2016–2026. Each game retains its source URL. No article text, publisher images, school logos or betting data are copied. NCAA championship histories provide champion cross-checks: https://www.ncaa.com/history/basketball-men/d1 and https://www.ncaa.com/history/basketball-women/d1 . These are not represented as MIT or CC-BY licensed site content.

Historical reconciliation remains documented in each dataset: 2018 LIU seed/ID, mutable team names and women's host-site/region labels. Oregon–VCU 2021 keeps Oregon's no-contest advancement and null scores; it is excluded from fitting/scoring as a played game. 2020 is cancelled, with no invented field.

Independent educational recreation; not affiliated with these publishers, the NCAA or any university. Library/font notices are separate in THIRD-PARTY-NOTICES.txt.