The movie is based on the book, Act of Vengeance by Trevor Armbrister, a fact-based story about the corruption that occurred during the United Mine Workers' presidential elections in 1969. It premiered on April 21, 1986. The film also portrayed the murder of Joseph ``Jock'' Yablonski.

Multi-choice problem: Is it true that is act of vengeance based on a true story?

Available options: --no. --yes.
The answer is:
yes