Who is the most dominant U.S. woman on road to Rio Olympics?

Katie Ledecky, Claressa Shields, Gwen Jorgensen, Simone Biles

U.S. women outnumbered the U.S. men in total athletes, total medals and gold medals at the London 2012 Games.

It appears women (not allowed to compete in the first modern Games in 1896) will continue to lead the American contingent in Rio, based on results since the London flame was extinguished on Aug. 12, 2012.

Swimming has become a “Big Four” sport, like men’s tennis, with Michael Phelps and Ryan Lochte being joined by Missy Franklin and Katie Ledecky.

The U.S. women’s gymnastics team is as deep as ever, with perhaps its greatest all-arounder of all time in Simone Biles. London Olympic champions Gabby Douglas and Aly Raisman are back, too.

The most recognizable U.S. track and field athletes are women — Lolo Jones (409,000 Twitter followers) and Allyson Felix (210,000). That’s just the start.

Four women are dominating in particular.

Simone Biles
Sport: Gymnastics
Credentials: 2013, 2014 World all-around champion; nine medals from last two World Championships
Last Defeat: March 30, 2013 (all-around competition only)

The 18-year-old Texan is on the short list of most decorated U.S. gymnasts, even though she hasn’t competed at an Olympics. Her nine Worlds medals are second all time among Americans behind Alicia Sacramone. This year, she can become the first U.S. woman to win three World and/or Olympic all-around gold medals.

Her weakness? The uneven bars. Biles captured World gold medals on floor exercise and balance beam in 2014 and silvers on vault the last two years, but she was fourth on bars in 2013 and 57th in 2014.

Martha Karolyi on Simone Biles’ dominance, Gabby Douglas, Aly Raisman returns

Gwen Jorgensen
Sport: Triathlon
Credentials: 2014 World champion; eight straight World Triathlon Series victories
Last Defeat: April 26, 2014 (World Triathlon Series competition only)

The former Ernst & Young accountant is in the midst of the longest top-level women’s triathlon winning streak since the sport was added to the Olympics in 2000. Jorgensen won her last two races by more than one minute each time, the largest margins of victory of any woman since 2010.

Her dominance is most apparent on the run. If anything can stop Jorgensen, it’s bike problems. She punctured a tire and finished 38th at the London Olympics. In her last defeat on April 26, 2014, she was held up by a bike crash in front of her.

Gwen Jorgensen leads historic U.S. triathlon sweep at Gold Coast

Katie Ledecky
Sport: Swimming
Credentials: Olympic, World 800m freestyle champion; World-record holder in 400m, 800m, 1500m frees
Last Defeat: Jan. 18, 2014 (200m, 400m or 800m freestyle in Olympic-sized pool only)

No woman was within 4.5 seconds of Ledecky in the 800m free last year, and none were within 27 seconds of her in the 1500m free. Alas, the women’s 1500m free is not an Olympic event. Her 1500m world record was faster than Ryan Lochte‘s time in the event at the 2004 U.S. Olympic trials, and she swam in mixed-gender races with her club team this past season.

Ledecky looks like an early overwhelming favorite in Rio in the 400m and 800m frees, but as the distances get shorter, she becomes beatable. She ranked No. 2 in the world in the 200m free last year, to Sweden’s Sarah Sjostrom. If she wants to swim the 100m free and make a U.S. 4x100m relay, she would probably have to slightly improve on her personal best.

Katie Ledecky faces decisions in 2015, 2016

Claressa Shields
Sport: Boxing
Credentials: Olympic, World middleweight champion
Last Defeat: May 13, 2012 (her only defeat)

The Flint, Mich., native is 52-1 and so intimidating that her 2014 World Championships first-round opponent’s trainer threw in the towel to end the fight at the 11-second mark. She was named Outstanding Boxer of the Tournament across all divisions.

A challenge for Shields, whose boyfriend is a sparring partner, has been finding women willing to compete against her. That’s an obstacle foreign to Biles, Jorgensen and Ledecky.

Rio 2016 Olympics day-by-day events to watch