LONDON -- They are trained not to care, to win with whatever ruthlessness is necessary. But there still might have been a moment, Andrea Petkovic conceded, when she felt bad she was beating her opponent so thoroughly in a first-round match at Wimbledon this week.
"It's always a difficult thing for me," Petkovic said.
The dreaded double bagel -- or 6-0, 6-0 -- was administered three times in the opening round of the women's draw, which tied the three in the first round of the 2013 US Open (another, embarrassingly, took place in the quarters that year, when Serena Williams shut out Carla Suarez-Navarro).
In the past 20 years, there have been 70 double bagels in 83 Grand Slam tournaments, including this year's Wimbledon, which breaks down to less than one per Slam. Notably, there were five at the 1998 Australian Open.
According to the WTA, Williams and Victoria Azarenka lead all women's players with seven double bagels in main-draw matches. Maria Sharapova is next on the list with six.
None of the top three was involved in this week's whitewashings, however. Instead, Petkovic defeated American Shelby Rogers, while Venus Williams shut out American Madison Brengle, and Angelique Kerber double-bageled German compatriot Carina Witthoeft.
Before this year, there had not been a Wimbledon double bagel in women's singles for six years.
And while it's certainly not fun to be on the receiving end, dishing out a double bagel isn't always fun, either.
For Petkovic, it was a fairly unpleasant experience earlier this week because her opponent was playing injured, and Petkovic is fond of Rogers, who has ties to Charleston, South Carolina.
"When I grew up, [I was taught to take] every match point by point," Petkovic said. "I tried to do that. That has helped me in a lot of tight situations. That's why I'm mentally very stable, and I play normally really well and in the deciding moments because I play point by point.
"But then when you're up 11-0, obviously you feel bad for the other person, especially somebody like Shelby that I really like and that I think is a great girl, but you just have to do what you have to do sometimes. It's just your job, and you can't let feelings get to you, as hard as it sounds."
Belinda Bencic called the double bagel "harsh on paper" but said it also can be misleading sometimes.
"Maybe it's not as easy as the match seems or something," she said. "Sometimes it is, but I don't really feel like there is a difference if you win 6-1 or 6-0."
Defending champion Petra Kvitova won her first-round match here 6-1, 6-0, one of 10 first-round matches in which the loser managed three games or fewer.
Of course, any way the one-sided victory is parceled out, it's easier winning than being on the receiving end, and American Madison Keys takes some pride in the effort it requires to pull off the double bagel.
"It's actually pretty hard to do, just because you have to keep your intensity so high and you have to stay so focused," she said. "I think there are just some days you're feeling it and playing well. You just kind of go with it."
Keys could not recall being double-bageled herself as a professional, but it's also not the kind of thing you generally document in your journal.
"It may have happened in juniors before, but I know it's been close," she said. "But there have been times when I literally have just been thinking, 'OK, get one game, or seeing the time, just get it to an hour.'"
There might be an extra nod at the net, players said, but generally speaking, the less said, the better after a love-and-love affair.
"You know, it happens," Caroline Wozniacki said. "I remember one time I lost to Serena [0-3 at the London Olympics], and she won the [gold medal] and only lost like two games in every match, so she was playing amazing.
"At the end of the day, you just have to get back out on the practice court and just keep going. It's sports. Sometimes you have bad days and some days your opponent just plays better than you. It happens."
Bencic remembers the time she was double-bageled by Wozniacki in Istanbul in 2014, "so I really know how it feels, and it's really not funny," she said.
"After the tournament and the same evening, I was in the locker room [and] I was like, 'What happened?'" she said. "It went so quickly. I was not able to win one game. It's really frustrating.
"But, I mean, after the next tournament you're very happy when you win the first game."