All earnings in French tournaments and the Davis Cup are directly taxable by French authorities, as are some sponsorship contracts.

Tsonga also pointed out that professional tennis players were independent contractors who typically had high earnings for a relatively short period and needed to maximize their savings to prepare for the time when their playing careers were over. To maintain his advantageous tax status in his Swiss canton, Tsonga is not permitted to work in Switzerland. That is not difficult given how many months a year he spends on the road, but it is odd in that he is unable to play in pro tournaments in Switzerland.

French players also cite the quality of life on the Swiss side of the border and, in some cases, the quality of education for their children as motivation. Some also like that they can have a lower profile in French-speaking Switzerland than in their own country. Also, one former player pointed out, they get fewer dirty looks when they drive their fancy cars.

But this does not mean they feel Swiss, a point underscored when the French sports daily L’Équipe gave a quiz this week to the French Davis Cup players. Tsonga incorrectly answered that the capital of Switzerland was Zurich instead of Bern, and none could name the Swiss national anthem (“Le Cantique Suisse”).

All five players, Simon included, answered correctly when it came to last season’s Swiss Super League club soccer champion (F.C. Basel).

“I just feel we are representing France no matter where we live,” Simon said. “I mean, we are not the only country where the players are not living in their country.”

That is certainly true. There are top players who seek tranquillity and optimal training conditions far from home, like Kei Nishikori of Japan, who is based in Bradenton, Fla. Maria Sharapova, who was born in Russia and continues to represent Russia, has spent most of her life in the United States (and trains in Bradenton at IMG Academy).