The Black Grimoire Turns Nearly Four Million Decklists Into Commander Advice

Field notes

The tool combines collaborative filtering from public Moxfield, Archidekt, and EDHREC decklists with commander rules and deck-structure analysis. Its stated corpus contains 3,996,039 decks, and the site describes six-hour recommendation reranking based on player choices. Collection imports accept ManaBox, Arena, or CSV exports; the homepage says those collections remain in the browser rather than being retained.