GANGNEUNG, South Korea — What must it be like to be 18 and crowned Olympic champion in all the predictions, only to find that someone younger may be better? And what if that someone is a friend and partner you train with every day?

Last fall, Evgenia Medvedeva of Russia was a consensus pick to win the women’s figure skating competition at the Winter Games. She was already a two-time world champion, undefeated in two years, increasingly graceful as an artist and technically savvy in her jumping. But skating can be a ruthless sport. And now Medvedeva’s time may have gone before it arrived.

She could still win gold on Friday, skating as Tolstoy’s tragic Anna Karenina. She sits in second place, only 1.3 points behind her training partner in Moscow, the 15-year-old Alina Zagitova. It would be premature to count Medvedeva out. But there is something awakening in Zagitova. She defeated Medvedeva last month at the European championships. In Wednesday’s short program, Medvedeva set a world record for points. Ten minutes later, Zagitova broke it.

Still, Medvedeva will be a central figure at these Games, gold medal or not.

It was Medvedeva who helped to argue — successfully — in December before the International Olympic Committee that not all Russian athletes should be banned from these Games because of systematic doping orchestrated at the 2014 Winter Olympics in Sochi, Russia.