Well, it's hard to say for sure. Maybe it's inspired by true events but has been dramatized and modified to make it more engaging. Or it could be completely made up.
I don't know specifically who they are in this story. They could be ordinary people whose story is unique and meaningful in a particular context, like two neighbors with an interesting friendship or feud.
It depends on your perspective. Some parts of the story might be based on real events, but there could also be elements that are exaggerated or fictionalized for entertainment purposes.
Sure it is. Bobby Fischer was a real person and his experiences and achievements in the world of chess are factual. His story is part of chess history.