The plot would go something like this:
You have an eccentric prodigy in Fischer challenging the Soviet chess dynasty in the midst of the Cold War.
Fischer, a control freak who rarely bothered to show up on time but dazzled with manic bursts of brilliant play, would be a dream part for many actors. You could even foreshadow his dark turn toward anti-Semitism and life on the fringe. Spassky was quieter but chafed against the same Soviet chess establishment that propped him up.