How many letters does the top answer for “author of back to the future” have?

The most common answer is zemeckis (8 letters).

Crossword clue: author of back to the future

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

zemeckis 8 letters wd-fact-v3

author of the future 67% similar → cohen

author of the road back 50% similar → remarque

director of back to the future 50% similar → thompson

wrote back to the future 50% similar → zemeckis