Why women-only chess tournaments exist

The first fact clears up half the confusion: there are no men-only tournaments. There are open events, where everyone plays, and women's events, which admit women only.

• A woman may play anywhere. Any open tournament, up to and including the world championship cycle by the general qualification path.
• The reverse is not true. A man is not admitted to a women's event - the single restriction by sex anywhere in chess.
• Two title tracks. The general ones (Grandmaster, International Master) and the women's ones, where the rating threshold sits roughly 200 points lower.
• Women earn general titles too. Many do. The women's titles do not replace them - the two tracks exist side by side.

So this is not a split into two leagues, as in physical sports. It is an additional line of competition layered on top of the open one.

At the top of the rating list men are far more numerous. The real question is why, and here there is a testable part and an untestable one.

The testable part is the difference in how many people play. There are many times more men in chess, and the larger a sample, the higher its maximum - purely statistically. Work by Bilalić and colleagues (2009), using the German rating list, found that the bulk of the gap between the top hundred men and the top hundred women is explained by exactly this.

The untestable part is any claim about innate differences in aptitude for the game. There is no convincing evidence for it, and confident statements in that direction go beyond what the data supports.

One well-known data point: Judit Polgár, the strongest female player in history, refused to play in women's championships on principle and spent years inside the world top ten of the open list - living proof that no ceiling is fixed by sex.

• A way in. A girl finds it easier to start where there are peers around her. Being the only girl among twenty is a classic reason to quit within a year.
• Professional opportunity. Women's events provide prize funds, invitations and a living to players who would otherwise never reach elite line-ups.
• Visibility. A women's world champion is a public figure and a role model who simply would not exist without that line.
• More players. If the participation gap really is the main cause, then anything that increases the number of women playing works directly on closing it.

• It signals inequality. A separate track with a lower title threshold reads as «the bar is lower here», even though formally it is a separate category rather than a concession.
• Weaker competition. Players improve against strong opposition; staying inside the women's circuit can slow the very best down.
• Two names for one achievement. Women's titles sitting beside general ones create confusion and devalue the former in the public eye.
• The logic of the sport. Chess has no physical advantage - the main ground for separation in other sports.

Tellingly, there is no consensus among women players themselves: some defend the system, others decline women's titles on principle. This is an argument about strategy, not about facts.

For someone running club nights the question is practical: how do you get more than ten per cent women into the room? What works:

• A women's prize inside the open event. Everyone plays together, with a separate award for the best result among women. For a club this is the best compromise by a distance.
• Mixed and family formats. Pairs, teams and family events lower the barrier better than any invitation.
• The atmosphere in the room. Remarks about an opponent and a condescending tone drive people away more reliably than any rule - and that is the organizer's responsibility.
• Invite in pairs. «Come along with a friend» works several times better than an invitation to one person.

Practical organizing: how to organize a tournament, the organizer's checklist.