In Bianca Andreescu, Serena Williams may be facing her charmingly arrogant heir

Serena Williams has been at this so long, even she seems a little bored by Serena Williams.

“To be in yet another final, it seems, honestly, crazy,” Williams said after advancing to Saturday’s championship match at the U.S. Open. “But I don’t really expect too much less.”

In any other player, this sort of talk would be self-aggrandizement. But in women’s tennis, only Williams is allowed to self-aggrandize – a privilege she regularly avails herself of. She’s earned it.

Open this photo in gallery:

For most of two years, Williams has been practically begging for someone to pull her off her perch and spare her the bother. She’s old and slow. Her power is still best-in-game, but not what it was.

She puts one in mind of a formerly great boxer who survives on his reputation. Everyone’s afraid to get too close, lest they are introduced to that big, right hand.

Williams’s defeated semi-final opponent, Elina Svitolina, admitted as much after their Thursday match. She’d had three break points in the first game of the encounter. She gave each one back and then spent the next hour and a bit rolling around on the ground in front of the Great One.

“If you don’t take it, she just grabs it,” Svitolina said. “And there’s no chance to take it back.”

Since her return from giving birth, Williams has been stuttering toward her final legacy – the women’s career Grand Slam leader. She needs one title to tie the record (24) and two to set it.

Twenty-four, it must be said, is a phony landmark. Australia’s Margaret Court set the record back when getting to that country took a month by birchbark canoe and few were willing to go to the trouble.

Often facing opposition in the Australian Open that amounted to some guy’s cousin and a kangaroo with opposable thumbs, Court won 11 Aussie majors in 14 tries. Were you to time warp the young Court in to play the young Williams, they’d need to rig the stadium sound system with a laugh track.

So 24 doesn’t really matter. Williams is already the best ever. But it matters to Williams.

Which is why Saturday’s final may be the one that breaks her.

It’s bad luck for Americans and headline writers everywhere that Williams will face Bianca Andreescu. It would have been simpler if it were some simpering Brit or a feckless Dane in front of her. They’re good people. They know when losing is the polite thing to do. Especially in New York, which is effectively Williams’s home court.

Charting Bianca Andreescu’s meteoric rise to the top of tennis

Andreescu does not strike one as a polite sort, despite her unfortunate state of Canadianness. After she’d beaten Williams via retirement in the Rogers Cup final a month ago, the 19 year old went over and bent the knee.

“I’m so sorry,” Andreescu said, taking her elder’s hand. “Are you okay?”

The whole exchange was sold as a moment of kindness, but you could see in Williams’s eyes that she did not appreciate the gesture. It was the sort of thing you do for the weak and infirm, not for someone you fear and respect.

You could feel the power draining from one player and transferring to the other. Williams was in that instant looking at her heir, and she did not like it.

Open this photo in gallery:

Williams was hurt, but it was hard not to read her mind – “This match doesn’t matter. Best to pull the chute and concentrate on the only tournament that does.”

That was a good decision. She has looked the business in New York. In the quarters and semis, she’s looked even better than that.

In her past two matches, Williams has lost a total of five games. That GOAT aura, circa 2015, is at high gloss. She looks unbeatable.

She looked the same way last year, until she was steamrolled in the final by Naomi Osaka. As it ended, Williams launched into a temper tantrum so bald-facedly cynical it would’ve embarrassed John McEnroe in his petulant heyday. That was when you began to think her time was nearing its end.

She’s been in one other final since, a comprehensive defeat at Wimbledon. The winner, Simona Halep, took the cunning strategy of making Williams move around.

Andreescu isn’t Osaka or Halep. She is a more complete player. She can overpower you or nick you to death with drop shots. She has the best forehand in the women’s game. She can run you around and chase all day. She seems to enjoy playing from behind. Once she beats you, she gives you that sad smile – “I’m so sorry. Are you okay?”

The Canadian newcomer is Williams’s charmingly arrogant doppelganger. One is now what the other once was.

If Andreescu wins Saturday – it’s a big stage, so it’s a big “if” – what’s left to Williams?

She’ll be 38 in a couple of weeks. At that age, Steffi Graf had been retired for nearly a decade.

By the time the Australian Open rolls around in four months, this chase for a number will have begun to seem desperate. Once she makes another final, all the stories about her most recent collapses will be recycled. There’s no way she quits now – not with an Olympics in the offing next August – but the pressure to win not just one, but two, will become burdensome. You can see how this might end depressingly.

So Saturday’s match is unusual, if not unique. On one side, the greatest and most feted women’s player of all time, someone whose legacy was secured many years ago. On the other, an upstart many people around the world are only seeing for the first time, someone who has future greatness guaranteed. And all the pressure is on the one of them you would not expect.

The easy pick here is Williams in a war. That’s what everyone expects. But Williams doesn’t win wars any more. She launches a heavy-artillery barrage up front and then expects surrender.

If Andreescu can weather that early assault, she may not just be winning the first of what looks like several major titles. She may be ending a one-woman empire that has defined the game of tennis in the 21st century.