"Your knees start knocking and your throat gets dry. Everybody's yelling and cheering for each team, so it's pretty involved and nerve-wracking."
The pressure hasn't prevented Karwasky from leading the U.S. Maureen Connolly Cup team for women 55 and older to ITF Seniors World Championship titles every year that she's been on the team, beginning in 2008.
"We've had a good team, good players," Karwasky says. "When it came down to the crunch, we had good doubles teams when we play for that last point.
"The team camaraderie helps when you're down and feel like you're down in the dumps."
As the team's No. 1 singles player, who has also made some key doubles contributions, Karwasky has been at the center of an impressive run of titles for the U.S. team, which has a chance to win its fifth straight overall this year.
"She's been in these situations forever, I don't know how many years," Connolly Cup teammate Sherri Bronson says of Karwasky. "But you call on your past memories and she's able to not get down on herself if things are not going well. She can pull it back together."
Selection for the Cup team is based on performance in U.S. competition throughout the year. Karwasky has consistently retained her place on the team by maintaining high ITF and United States Tennis Assn. rankings. Last year, she was ranked No. 2 in the U.S. in 55-and-over singles and No. 1 in doubles. She won National Indoors titles in singles and doubles, and the National Hard Court doubles title with teammate Mary Ginnard, who has been added to this year's Connolly Cup team. Karwasky finished the year as the No.1-ranked 55-and-older player in the world.
"It's important to play well all year round," Karwasky says. "It's pretty hard to do.
"The competition in the United States is pretty tough."