How do you define greatness? What is the formula best served to determine the greatest athletes in sports? Is it victories? Championships? Records? Is it accomplishing the most with seemingly the least? Does it change depending on the sport?

Fifteen months ago, nestled into the corner of a cushy couch in her Vail, Colorado, home, Lindsey Vonn said that she didn't just want the record for World Cup wins by a man or woman -- she needed it. That was her definition of greatness, the tangible proof she believed she needed to demonstrate to others -- and perhaps even to herself -- that she was the best ever.

But in sports, it's never that simple. Vonn's body, specifically her knees, refused to cooperate. A vicious crash in preseason training this past November further damaged her left knee, which was barely stable before her latest mishap. After six weeks of rehab and recovery, she raced in Cortina d'Ampezzo, Italy, on Jan. 19 and 20 in excruciating pain. On Friday, she finally acknowledged what her body had been telling her for months: It's time to stop. Next weekend's world championships in Are, Sweden, will be the last races of her career. Those runs will be more ceremonial than competitive, an emotional opportunity to wave goodbye one final time. In Sweden, Vonn's career will come to an end with 82 World Cup wins, more than any woman in history and three shy of Ingemar Stenmark's record of 85.

"Retiring isn't what upsets me," she said in a statement released Friday. "Retiring without reaching my goal is what will stay with me forever."

But greatness is about far more than records. Especially in a sport like downhill skiing, as much a test of courage as an evaluation of skill, where competitors hurl themselves down ice-covered mountains chasing some invisible line that separates stepping atop the podium from rolling into an emergency room. You have to be stubborn. Fearless. Driven. And ferociously competitive, almost unhealthily so. Perhaps no one has defined those characteristics better and pushed their body further in the pursuit of greatness than Vonn.

Injuries forced her to miss part of six World Cup seasons as well as the 2014 Sochi Olympics. Over the years, she's shattered her humerus, broken her ankle, severed a tendon in her hand. There have been surgically repaired knee caps, broken legs and torn cartilage, meniscus and ligaments in both knees. Concussions.

The list is quick to read but the comebacks never easy. After shattering her humerus, she couldn't pick up a pencil for months. She had to tape her ski poles to her hands when she first returned. In her statement on Friday, she revealed another surgery that she underwent last spring to remove a portion of cartilage that had split from a bone in her knee. At her crash before this season at Copper Mountain, she says, she tore the lateral collateral ligament and sustained three fractures in her left knee.

Her knees are a jumbled mess. When she wakes up each morning, she says, her body cracks and groans like the creaks of a 100-year-old home. There are stretches and a half hour on a stationary bike before she can feel properly functional again.

At the end of Vonn's career, this has been her norm. This is what it has taken to compete. Plus regularly wearing a brace. Keeping her knees elevated whenever she can. The squats, the stretches, the two-hour workouts with her trainers, all designed to squeeze every single race she could out of her 34-year-old body.

"My body is beyond repair and isn't letting me have the final season I dreamed of," she wrote. "My body is screaming at me to STOP and it's time to listen."

Those close to Vonn long wondered and worried whether she'd retire before it was too late, before the injury she wouldn't be able to come back from. Her sister Karin once said one of her greatest fears was Lindsey pushing herself too far and suffering an injury she'd never be able to walk away from.

But there was one problem -- even with everything Vonn had been through, she continued to succeed. She won five races in 2018 and a bronze medal at the Pyeongchang Olympics. Before last season, one of Vonn's coaches, Chris Knight, guessed that Vonn's body was "50 to 60 percent" of what it once was. "And that still puts her as the top two or three ski racers in the world," he said.

Less than a year later, the body has finally defeated the mind. Disappointing, sure. Sad, of course. But in many ways, the end so many saw coming. With Vonn, there has always been so much to unpack. But ultimately, her legacy isn't about the records. The medals. The World Cup globes that line the custom-made shelves above the fireplace in her home. It's not about the commercials or magazine covers or the personal relationships with fellow elite athletes Tiger Woods and PK Subban. Nor is it about what might have been.

Lindsey Vonn achieved heights no woman before her ever had. She paved the way for 23-year-old American wunderkind Mikaela Shiffrin, who already has 54 World Cup wins and, barring something unforeseen, will likely catch and pass Vonn's total before her career is through.

But that shouldn't take anything away from Vonn's career. Her legacy, ultimately, will be as one of the most successful, resilient athletes in American sports history. Each morning she wakes up for the rest of her life, she'll likely feel sore. The aches should serve as a reminder not of the finish line but rather the hard work, mental toughness and determination it took to compete in the first place. Time after time, her body told her no. And every single time she fought back until the answer became yes. That's greatness.