There could be a male biological advantage across the population without females being less smart as a population: https://en.wikipedia.org/wiki/Variability_hy

There could be a male biological advantage across the population without females being less smart as a population: https://en.wikipedia.org/wiki/Variability_hypothesis https://en.wikipedia.org/wiki/Variability_hypothesis But that's hard to separate from the fact that there are just so many more males in the pool of chess players.