Venus Williams and her sister Serena will play each other in a quarterfinal match scheduled for today at the U.S. Open in New York. The last time they competed against eachother was in June, when Venus beat Serena in the finals of Wimbledon. Today’s match will also be the 17th Williams vs. Williams showdown of their professional career.

“If I had a sister and she wasn’t very good, then it would be just not really a big deal because I would beat her,” Venus said Monday, after she and Serena assured a quarterfinal matchup.

“I’m glad we’re both pretty good at it, because I always use her,” she said. “If I’m going somewhere and they give me a nice gift I’m like, ‘Well, my sister, she’s not here, but she would love that.’ If she was no good then I wouldn’t be able to do that. And I always keep it. She doesn’t even know about it half the time. I guess maybe she’ll know about it now”, Serena added.