Katie Ledecky is her own biggest competition

In London in 2012, Katie Ledecky was an unknown who shocked the swimming world by beating the world’s best with one remarkable swim on the sport’s biggest stage. She wasn’t expected to win anything, but she did, and for a 15-year-old, that was enough.

Four years later, she’s transformed into the world’s most dominant swimmer, without a doubt the greatest women’s freestyler of all time. She’s not just looking to win, she’s looking to smash. Her primary competitors are her own personal bests. She’s so unbeatable that silver has never touched her neck -- just Olympic gold and nine World Championship golds. She could win gold at every event she’ll swim in Rio and find herself disappointed if she didn’t also break any of her various world records.

Ledecky doesn’t mess around with the backstroke, butterfly and breaststroke. She exclusively swims freestyle, and she completely obliterates the competition. Between the 2013 and 2015 World Championships, Ledecky raced in nine events. She won them all. She’ll race in three individual events in Rio, and she holds the world record in two of those.

She can win short races -- she won the 200-meter freestyle at the last World Championships. She can win long races -- last year, she set the world record in the 1,500-meter freestyle in a preliminary round at the World Championships, when she was hypothetically supposed to be taking it easy. Her world record was an accident. (Sadly, we won’t see her swim the 1,500-meter free in Rio, since it’s not a part of the women’s Olympic program.)

Her feature event is the 800-meter freestyle, the same one she stunned everybody in four years ago. Her gold medal time in that event was .53 seconds off the world record -- not bad for a teenager. But now Ledecky owns the world record, as well as the second-best race of all time, third-best race of all time, as well as the fourth-, fifth-, sixth-, seventh-, eighth-, ninth-, 10th- and 11th-best races of all time.

At the American trials in Omaha, second-place finisher Leah Smith recorded an 8.20.18, making her the third-fastest in the world in the event behind Ledecky and Australia’s Jessica Ashwood. That should be good enough for a bronze in Rio. Ledecky beat her by 10 seconds, a swimming eternity.

A Sports Illustrated profile revealed that her success baffles just about everybody. She’s shorter than most swimmers, and her parents and coaches aren’t quite sure how this laid-back, smiling woman transforms into a furious monster when she hits the pool.

Overall, American swimming might be in for a down year in Rio. Stars such as Michael Phelps and Ryan Lochte are aging, and younger competitors like Missy Franklin aren’t performing to their lofty goals.

But Ledecky is at her best. She was the only American to medal in a non-medley event at last year’s World Championships. Luckily, she won four golds, which was enough to make the whole team look good.

And she’s only getting better. She’s already thinking about 2020, when she has said she hopes to qualify for the 100-meter freestyle -- because complete dominance in the 200, 400, 800, and x200 apparently will not be enough for her.

That is a testament to Ledecky’s willpower: She’s the best in the world at so many things, and she can’t stop thinking about other ways to achieve greatness.