PROVENANCE & CREDIT

The sources behind the record.

Data has a source, a timestamp, and limits. Reports show which version was used and what it can support.

EXPECTED PERFORMANCE & REFEREES

nflverse officials & team history

Accepted penalty totals, historical box scores, schedules and head-referee assignments support expected-versus-actual comparisons. Conflicting referee assignments are excluded; team/referee records include sample counts.

Officials data documentation ↗

CC BY 4.0: nflverse / nflfastR; schedules additionally credit Lee Sharpe. Frozen source bytes, joins, transformations and exclusions are documented in the public repository.

SCHEDULES & PLAY-BY-PLAY

nflverse / nflreadr

Game schedules, play records, and historical data power the archive. Clean data and raw postgame builds have different availability. Reports identify the snapshots actually used.

Availability & update schedule ↗

Dataset rights are separate from package licenses. Terms and provenance are recorded with snapshots.

EXPECTED POINTS & WIN PROBABILITY

nflfastR

Established state-based calculations provide context. Reports identify their model family and state assumptions. Unsupported rule-era states remain unavailable.

nflfastR documentation ↗

Observed WPA is context, not an estimate of penalty or error-attributable impact.

FOURTH-DOWN DECISIONS

nfl4th

Fourth-down analysis compares expected outcomes of valid actions. Support depends on verified model semantics and validation of the applicable rule era.

nfl4th documentation ↗

Model records identify the exact implementation and validation status.

MANUAL EXECUTION CHARTING

FTN Data via nflverse

Charting is available from 2022 onward and can be delayed or partial. Joins use documented game/play IDs; field-specific coverage stays visible.

FTN loader & attribution ↗

FTN charting carries CC BY-SA 4.0. Attribution, license links, modification notices, and applicable share-alike terms must be preserved.

Attribution and use

FTN charting: FTN Data via nflverse, under Creative Commons Attribution-ShareAlike 4.0. Counts and annotations may be filtered, joined, and summarized from source data; they do not imply FTN endorsement.

Software licenses do not automatically license accessed datasets. No league logos, proprietary grades, or video are required. Review-evidence links do not grant permission to republish media.

Freshness is observed, not promised

FTN documentation describes charting within 48 hours; nflverse refreshes four times daily in season. Upstream timing varies. Statistics can change after initial publication. Report timestamps describe the actual record rather than a promised deadline.

Source documentation checked September 23, 2026. DATA_SOURCES.md in the repository contains verification details and access limitations. Individual snapshots provide actual retrieval times.