Court and King. Evert and Navratilova. Graf and Seles.
Just those surnames are enough to conjure up some of the greatest battles in women's tennis.
The modern era has witnessed its fair share of classic matches but the dominance of Serena Williams, and to a lesser extent her older sister Venus as well, has led to an absence of an epic rivalry in recent years.
Even matches between both sisters - Serena leads 17-11 - tend to be lukewarm affairs.
That void has been noticeable, former world No. 1 Lindsay Davenport said yesterday.
The American added: "That's what's always driven the sport of tennis through the last 20 or 30 years. It hasn't seemed like we've had a great rivalry in women's tennis the last few years."
The 41-year-old retired in 2010 with three Grand Slam titles to her name, although that tally could easily have been doubled.
Asked how her rivalry with the Williams sisters made an impact on her career, Davenport burst into laughter: "Well, it stopped me from winning more Grand Slams."
Although she leads the head-to-head 14-13 over Venus, the 37-year-old got the better of her in three Slam finals. Davenport's record against Serena, 36, was less close, 10-4 in favour of the latter, and includes a loss in the 2005 Australian Open final.
Not that Davenport, who was a guest at a conference for sporting parents presented by Tiffany & Co. yesterday at the Singapore Indoor Stadium, bears any grudges.
She said: "It just forced everybody in that generation to get better, to train harder off court, to try to get a little bit better at handling power.
"It definitely forced me to try and become a little bit quicker and stronger. A lot of times with rivalries, what really helps is a difference in personalities or playing styles.
"I think we have the opportunity, we need the players playing more often healthy."
Like Davenport, Arantxa Sanchez-Vicario is a legend ambassador for the ongoing BNP Paribas WTA Finals Singapore.
Referring to her contests against Steffi Graf, Sanchez-Vicario told The Straits Times: "It's definitely nice that people remember the rivalry that Steffi and I had in the 90s and when you watch these matches on TV, people remember how good the matches (were).
"It is important that every generation has matches and rivalries that people want to see for a long time."
The Spaniard's head-to-head with Graf may be 8-28, but she did prevail over the German in some key matches, including the 1989 French Open and 1994 US Open finals.
Sanchez-Vicario said the openness of the women's game today has made it difficult to predict the next big rivalry.
But she tipped fellow Spaniard Garbine Muguruza, world No. 1 Simona Halep and third-ranked Karolina Pliskova to be some of the key players.
Pliskova is in Singapore, assisted by former pro Rennae Stubbs, who believes the big-hitting style of the white group - where Pliskova is drawn - and the counter-punching style of the red group will make for interesting semi-final matches.
"I like the rivalries where the big-hitting players and defensive players are playing against each other, where it's defence against offence," the Australian told ST yesterday.
"The rivalries between styles of play - that's interesting and fun to me."