Serena and Venus emphasize changing the game

The majority of the planet thinks of Serena and Venus Williams as champions of the tennis court. When the sisters stand on opposite sides of the net, many view them as competitors vying for titles. The two sisters see it much differently.

"Ever since we were little girls, you've compared us to each other," Venus narrates in Nike's newest video.

From their game styles, on-court demeanors and of course Grand Slam trophies, fans and tennis enthusiasts have compared and dissected the duo for decades. For the former world No. 1's it had always been about changing the game.

"It's funny. You saw two tennis players trying to win a game," Venus said. "We saw two sisters changing it."

Serena and Venus hold a total of 122 titles and they are still not finished "changing the game." At 40 years old, Venus will start her 22nd US Open campaign against No. 20-seeded Karolina Muchova on Tuesday night. The opening round match will mark the first career clash between the two. In the same half of the draw, Serena will take on Kristie Ahn.

Serena, who has come close to tasting Grand Slam title No. 24 in two major finals, is heading into the hardcourt event feeling unsatisfied.

"Obviously I'm never satisfied," Serena told press. "That's been the story of my career. So, yeah, it is what it is. I took a year and a half off for a baby. So I don't know. It's like I'll never be satisfied until I retire."

At last week's Western & Southern Open, Serena was just two points away from entering the final eight, but could not close out Maria Sakkari. She appeared to be slightly fatigued and struggled mentally in the third set.

With some matches under her belt, Serena will have another chance at match play, though for far greater stakes, this week in New York.