But even now, her gross income in five years as a pro barely tops $200,000, which sounds substantial, except that it averages out to an extremely modest $40,000 a year -- before expenses.
Nevertheless, for players from the former Eastern Bloc, earning $40,000 per year is the equivalent of extremely good pay.
"They can live like millionaires," said Josef Brabenek, a Czech émigré who has coached and directed tennis development programs on the international level. The government often helps with tax subsidies.
"In the Czech Republic," Brabenek said, "$40,000 is a lot of money."
Less so in the United States. Mattek's average yearly income of $58,000 is nearly double the official poverty line. Yet even though Mattek is having one of her better years, she still doesn't have much net income to show for it.
At Wimbledon, she earned $6,620 for reaching the second round in women's doubles and $2,380 for reaching the second round of mixed doubles.
At Flushing Meadows, she earned $16,500 losing in the first round, and was guaranteed $5,000 more for competing in the women's doubles.
That raised her gross income for the year to about $125,000 (including $2,000 for wearing those two patches). Stacked against airline, hotel, food, and tax bills, the gamble remains on shaky ground.
Mattek takes it one day at a time.