I doubt what made the Polgar sisters great was innate intelligence.
Their father, Laszlo Polgar, was himself a fairly strong chess player, and it is well-known that intelligence is heritable. In addition, Judit Polgar at least (I don’t know about the others) was a child prodigy, implying that she had a great deal of innate ability. Furthermore, chess requires very good working memory (due to something called the touch-move rule forcing players to calculate variations mentally), and it is theorized that working memory may actually be intelligence, further supporting the “innate ability” hypothesis.
Their father, Laszlo Polgar, was himself a fairly strong chess player, and it is well-known that intelligence is heritable. In addition, Judit Polgar at least (I don’t know about the others) was a child prodigy, implying that she had a great deal of innate ability. Furthermore, chess requires very good working memory (due to something called the touch-move rule forcing players to calculate variations mentally), and it is theorized that working memory may actually be intelligence, further supporting the “innate ability” hypothesis.