We can't expect Serena Williams to win them all

— -- MELBOURNE, Australia -- With the Australian Open championship match tied at a set apiece and Angelique Kerber leading 3-2 in the sixth game, Serena Williams moved toward the net to return her left-handed opponent's forehand, only to have the ball whack her right shoulder. She raised her arms, threw back her head and howled.

If that video went viral, it would not be as shocking as seeing her also go on to lose the match 6-4, 3-6, 6-4 to Kerber, who was playing in her first Grand Slam final.

Sure, there were questions about Serena before the tournament started; she had a long layoff after losing in the US Open semifinals and falling short of the Calendar Slam, and withdrew from the Hopman Cup with a knee injury.

But after the way she played her first six matches here -- she never lost a set and beat one opponent in just 44 minutes -- everyone expected Serena to win Saturday, add a seventh Australian Open title to her résumé and, more importantly, match Steffi Graf's record for the most Grand Slam titles in the Open Era with 22. It was the same sentiment heading into the US Open semifinals before Roberta Vinci pulled off one of the biggest upsets in tennis history.

Even Kerber said before Saturday's match that so many people expected Serena to win that she felt no pressure at all, that she had "nothing to lose." And why wouldn't we expect Serena to win? She usually does, especially in Grand Slam finals, where she was 21-5 heading into Saturday. We always expect to see her prevail. She is arguably the best player in the game's history.

No athlete can win every competition, though. Not Roger Federer. Not Kobe Bryant. Not Derek Jeter. Even American Pharaoh would lose eventually.

"It's interesting. I mean, every time I walk in this room, everyone expects me to win every single match, every single day of my life," Serena told reporters after Saturday's match. "As much as I would like to be a robot, I'm not. I try to. But I do the best that I can. I try to win every single time I step out there, every single point, but realistically I can't do it. Maybe someone else can, but I wasn't able to do it."

No, she wasn't. She made 46 unforced errors, half of them in the first set alone, often thrusting out her arms in frustration. She went to the net many times only to see it backfire, winning less than half her net points (15 of 32).

Kerber said she enjoyed every second of the match and that Serena probably felt more pressure with everyone expecting her to win and Graf's record so tantalizingly close. Pressure usually doesn't help. Earlier this month at Brisbane, Andrea Petkovic said she was overwhelmed by how much pressure Serena was under when trying to complete the Calendar Slam.

"You guys put so much pressure on her there [last year]," Petkovic told reporters. "If she had won, I would've put her in my idol list forever and I would bow down in front of her. ... She was on every cab, every bus, on every TV, on every store. She would've had to lock herself in a tiny room and never get out again if she wanted to get away."

Williams won't feel the pressure of a Calendar Slam this year. But was it nerves and anxiety over trying to tie Graf's record that caused her sup-par play Saturday? Williams vigorously denied it.

"I was nervous before the match. Once it got started, it was so intense from the beginning until the end that I didn't really have time to be nervous," she said. "No, I didn't think about the record at all. More or less I thought just about winning this match. It wasn't necessarily the record for me."

Despite the loss, Williams was incredibly gracious after the match, congratulating Kerber and smiling so much as if she had won herself. "Really?" Serena said when asked about that. "I should get into acting."

Deep down, Serena was not happy to lose. She never is. That's one reason why she wins so often. And as she showed throughout this tournament up until Saturday, her game is still phenomenal. It will eventually begin to decline -- have we seen it already given the past two Slams? -- but she still has a solid chance to match and better Graf's record. But, as we saw Saturday, there are no guarantees.

"It's still tough to beat Serena," said Kerber, whose ranking will rise to No. 2 with her win. "But I think that a lot of new and good players are coming. They will challenge Serena. They will challenge me. They will challenge all the good players. Let's see what happens in the next few months or few years."

In the meantime, root for Serena to win. Just don't expect her to do so every time. She might be the best ever, but Serena is no robot. She is an athlete.