Six hunting three straight gold medals
Jamaicans Usain Bolt and Shelly-Ann Fraser-Pryce are just two of a group of six track and field athletes who hope to win their events for the third time in a row at the Rio Olympics.
The others - Poland's Tomasz Majewski, Ethiopia's Tirunesh Dibaba, New Zealander Valerie Adams and Barbora Spotakova of the Czech Republic - face varying degrees of difficulty as they seek to make their own bit of Olympic history.
Their quest will command attention when competition in athletics starts on Friday.
Majewski, the 2008 and 2012 shot put champion, faces an uphill task. Though the Olympics seem to bring out the best in him, the 35-year-old has slipped out of medal contention at the World Championships, indoors and outdoors, since his triumph at the last Olympics in London.
The trio of American Joe Kovacs, German David Storl, and Jamaican O'Dayne Richards took the medals at last year's Worlds.
If Majewski wins anyway, he will become the first man to win the shot put three times. The first man to win it twice was American Parry O'Brien, who triumphed in 1956 and 1960.
Adams' domination of the women's shot put ended with knee surgery and forced her out of the World Championships last year. In her absence, Storl's teammate, Christina Schwanitz, took the gold medal.
Adams had beaten Schwanitz at the 2013 World Championships handily.
Dibaba hadn't ever lost a 10,000-metre race in her life until this year when she placed third to compatriot and current 5,000-metre World champion, Almaz Ayanna, late in June.
BEST LONG-DISTANCE RUNNER
Considered the best long-distance runner ever, 'Tiru' did the 5,000-10,000m double in 2008, but won bronze in the shorter event in London. Her big cousin, Derartu Tulu, is the other woman to have won the 10,000m twice.
Javelin world record holder, Spotakova, isn't as consistent as she used to be and placed well down the standings in the World Championships. She was, however, ranked number one in the world for 2015 by the respected US publication TRACK AND FIELD NEWS.
Still, with World champion Katharina Molitor of Germany also inconsistent, the Czech might have a chance.
Success for Bolt, Frazer-Pryce, Majewski, Dibaba, Adams or Spotakova would bring them in line with the likes of Czech javelin thrower Jan Zelezny and Victor Saneyev, the Soviet triple jumper, as three-time Olympic winners.
There is, however, an even more select group of athletes who have won one individual event four times.
The Americans Ray Ewry, Carl Lewis and the late Al Oerter did it in the long-discontinued standing high and long jumps, the long jump and the discus, respectively.