"Probably against my sister [Serena]," Venus replied. And what was it like? "Horrible," she said.
Those sentiments have probably not changed over the past 20 years. Venus and Serena remain fierce on-court rivals and their most recent clash, in the semi-finals at Charleston on Saturday, drew a crowd of 9,538, a single-session record for the Billie Jean King Court.
It was the first time the two sisters faced off since the final of the 2009 WTA Championships and the excitement around the match was understandable. Serena, however, was not too thrilled.
"I don't love playing her," she said. "If I win, I'm not super excited, and if I lose I'm really not excited. She's [the] toughest opponent I've ever played, and I think she's beaten me the most of any player."
On Saturday, Serena, the reigning world No 1, recorded a comfortable 6-1, 6-2 win to improve her record against Venus to 14-10.
When the two sisters met for the first time - at the 1998 Australian Open - Martina Hingis was the top-ranked player in women's tennis and Lindsay Davenport had to yet to win a Grand Slam.
Venus, 32 now and elder to Serena by 15 months, won that match and five of their first six duels, but she has been living in the shadows of her younger sister since those times.
She still remains an inspiration for Serena, though, especially after the way she has conducted herself since being diagnosed with the debilitating autoimmune disease Sjorden's Syndrome.
"It's so inspiring and hard at the same time," Serena said on Saturday. "I've been her biggest fan even more so ever since she found out about her disease.
"I don't make excuses. I think ultimately I play better because of that. Like I think about my sister and her not even being able to play at some days at her best level, and I think I have zero excuses."
Serena has come a long way from those pre-teen years when she just wanted to be as good as Venus.
"I was never the one that was supposed to be good," Serena said. "I was never the one that was supposed to be a great player. But I was determined not to be a statistic. So that was the only reason I played tennis. I was a copycat, basically."
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