Their games are interchangeable and invaluable.
Kelly says she is 5-foot-4, and Kylie claims to being the taller of the two at 5-51/2.
And it's safe to say that the sisters play much taller.
They can disrupt an opponent's flow with their tenacious defense. They simply make bringing the ball up the court a miserable experience for the opposition - and a tiring one.
They compete with an extra gear, overdrive.
And while statistics don't do them justice, here's one that gives their true value: South Jersey Group 4 championships.
A Washington Township team that had a rare losing season the year before their arrival has won three straight sectional titles with the two manning the backcourt.
"They have such a love for the game and are a joy to coach," Washington Township coach Jenn Natale said.
Not so much a joy to coach against.
"They are tough kids, who are not afraid of contact, set great screens, and they do all you want a player to do," Rancocas Valley coach Anthony Corrado said. "I really admire the way they play."
So now as seniors, the two hope to take that next postseason step, although with defending Group 4 state champion Rancocas Valley moving from Central to South Jersey Group 4, that won't be easy.
Like many basketball siblings, the Giedemanns have engaged in countless games of one-on-one, and many according to both have become a little heated.
They don't give an inch to opponents, so they aren't going to do that with each other.
Yet an indication of how much they care for each other came when they made their college choice. Both will attend Holy Family.
"I originally said that I don't want to go to college with her, that I need my space," Kylie recalled, laughing.
Yet when the realization came that they would be separated, it was too much for either to contemplate.
"I realized I can't do this alone," Kylie said.
Her sister agreed.
And now they will have one final run together in high school.
"It's gone by too fast," Kelly said.
Both will savor every moment during their senior year, and so should those who go watch them play. That's because it is difficult to imagine two players getting more out of their ability and enjoying themselves so much along the way.