Boxing and kickboxing champion Lucia Rijker, who also played the part of Billie "The Blue Bear" in this movie, was Hilary Swank's boxing coach.
Producer Albert S. Ruddy loved the story and was determined to make it into a movie and spent four years trying to find backers who were interested in helping him make it. "I couldn't get anybody interested", he said in an interview, "and I'm talking about people who are friends of mine, people I've done business with for years. They'd tell me, 'Who wants to see a movie about two old grizzled guys and a girl fighter?'" Eventually, he found someone interested, Clint Eastwood. He read the script and said "It's a downer...but God, it's gorgeous."
Writer Paul Haggis was directing Crash (2004) and was scheduled to direct this movie when Clint Eastwood (who was to act only) asked to direct it as well. Haggis agreed to step aside as director.
Jerry Boyd (a.k.a. author F.X. Toole) died a month after learning that Clint Eastwood had signed on to make a movie out of his work.