How many letters does the top answer for “author of the longest yard” have?

The most common answer is reynolds (8 letters).

Crossword clue: author of the longest yard

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

reynolds 8 letters wd-fact-v3

English portrait painter and first president of the Royal Academy (1723-1792)

author of devil's yard 50% similar → andric

director of the longest yard 50% similar → reynolds

wrote the longest yard 50% similar → reynolds