How many letters does the top answer for “author of the maltese falcon” have?

The most common answer is hammett (7 letters).

Crossword clue: author of the maltese falcon

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

hammett 7 letters wd-fact-v3

United States writer of hard-boiled detective fiction (1894-1961)

huston 6 letters wd-fact-v3

United States film maker born in the United States but an Irish citizen after 1964 (1906-1987)

wrote the maltese falcon 50% similar → hammett, huston