Story lines Women's gymnastics

After 40 years helping some of the greatest gymnasts of all time soar to Olympic gold — from Nadia Comaneci to Mary Lou Retton to Nastia Liukin — Martha Karolyi is ready to say goodbye. The U.S. women's national team coordinator is retiring after the 2016 Games.

The five-woman group Karolyi is bringing to Rio de Janeiro — Simone Biles, Gabby Douglas, Aly Raisman, Madison Kocian and Laurie Hernandez — has the perfect going-away present in mind: gold. Lots and lots of gold. Maybe all six available, something that's never been done by one country in a single Olympiad.

It's a testament to the empire Karolyi has built since taking over the program in 2001, that it's not merely hype but entirely plausible — a luxury afforded when you have the three-time reigning world champion (Biles), the defending Olympic champion (Douglas), a three-time Olympic medalist (Raisman) and the reigning uneven bars world champion (Kocian) on the roster.

The gap between the U.S. and the rest of the world has grown since the "Fierce Five" rolled to the team gold four years ago. If the Americans do what they've done at every major international event since 2011, Karolyi's final meet will be more of an extended victory lap.

Some things to watch for as the rest of the world looks for a ponytailed version of "The Miracle On Ice" in search of an upset:

The Simone show

The 19-year-old Biles has spent the past three years pushing the boundaries of her sport while putting together a winning streak that is three years and counting, with no apparent end in sight. She's won 14 world championship medals (10 of them gold) since 2013 and is poised to become the fourth consecutive American to win the Olympic all-around gold. The Spring, Texas, native is a mix of athleticism and daring. Her "Amanar" vault is the closest gymnastics gets to perfection these days, and there's a real chance she could win up to five medals on her own: team, all-around, vault, floor exercise and balance beam.

Nov. 1, 2015 - Glasgow, United Kingdom - CLAUDIA FRAGAPANE from the United Kingdom competes on the floor during the last day the event finals of the 2015 World Gymnastics Championships held in Glasgow, United Kingdom. (Cal Sport Media via AP Images) ORG XMIT: CSMAP

Encore part 1

Douglas is attempting to become the first reigning all-around champion to repeat in nearly 50 years. While topping Biles seems unlikely, the 20-year-old Douglas could follow in the footsteps of Comaneci, who won the all-around in Montreal in 1976 and earned silver in Moscow in 1980. Douglas' path back to the Olympics has been bumpy of late. Though she was runner-up to Biles at the 2015 world championships and captured the American Cup in March, she struggled at times during the selection process and parted with coach Kittia Carpenter in early July.

Encore part 2

Raisman was the oldest member of the "Fierce Five" in London while winning three medals, including gold on floor exercise. The 22-year-old — nicknamed "Grandma" by some of her younger teammates — heads to Rio as arguably the best gymnast on the planet not named Biles. Raisman was second to Biles at the U.S. championships and the Olympic trials. She credited longtime coach Mihai Brestyan and her commitment to doing "8 million routines" as the key to her resurgence at a time when some American stars are well into retirement.

Missing in action

Romania, which has finished on the podium in every Olympics since 1976, failed to qualify for the team competition after struggling at the 2015 world championships last fall and slumping at the end of the Rio test event in April. A broken finger injury to star Larisa Lordache didn't help. The Romanians will be represented by only one gymnast, 28-year-old Catalina Ponor, who will be making her fourth Olympic appearance and serve as her country's flag bearer during opening ceremonies.

Seventh heaven

Oksana Chusovitina of Uzbekistan competed in her first Olympics before most of the women she will be competing against in Brazil were born. The 41-year-old will be the oldest female gymnast in Olympic history when she appears in her seventh games. Her best chance to medal will come on vault, an event she won silver on in Beijing eight years ago. "It's a pity there are no points for age," Chusovitina said.

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