I don't find strange that top chess master is always male either.

No, the Bell curve explains that quite simply.

"So the scientists compared the ratings of the top hundred male and top hundred female players from Germany. And they found that the men indeed outperformed the women. However that difference can be almost entirely explained by statistics. Because the larger the population, the wider the range of measured scores—the bell curve has a longer tail. And because many more men play than women, the best male players are extreme outliers on that bell curve. As more women play, a few should also reach those extremes, right out there with the men. To which one might be tempted to say: Checkmate."

bullshit