Credits and licences
Last updated 2026-10-20
Our own code
The tools and page layouts are written for this site. The pages make no requests to other servers.
Plays, logo and diagrams
Every play, formation, defense and drill diagram on this site is drawn by our own play engine from generic concepts; none is copied from a league’s or team’s playbook. The logo and icons are our own drawings.
Third-party material and sources
| Name | Used for | Licence |
|---|---|---|
| pdf-lib 1.17.1 (Andrew Dillon) | Writes the playbook, wristband, call sheet, template, diagram and score sheet PDFs in your browser; the unmodified file is served from /vendor/pdf-lib/ with its licence | MIT (bundles tslib — Apache License 2.0, pako — MIT/Zlib, @pdf-lib/standard-fonts and @pdf-lib/upng — MIT) |
| NFL FLAG Official Playing Rules (revised 2025-03-24) | Facts summarised in our own words on the rules page, the rule check in the play designer, the field dimensions and the rules-card preset, with section numbers and dates | Facts; source linked on the pages. NFL FLAG is a trademark of the NFL; not affiliated |
| NFL 2026 Official Playing Rules, Rules 1 and 7 | Field measurements on the football field diagram; seven players on the line in the 11-a-side rule check | Facts; source linked on the page |
| NBA Rule No. 1 and NBA court diagram | Court measurements for the basketball court diagram and the basketball play designer | Facts; source linked on the page |
| Sports Dimensions Guide: Basketball (Government of Western Australia, citing FIBA) | FIBA court measurements in metres | Facts; source linked on the page |