Now, another Olympic skating controversy has gripped die-hard and casual fans alike. Gold-medal favorite Kamila Valieva, 15, gave a test sample that later tested positive for the banned substance trimetazidine on December 25, the day she won the Russian national championship.But the positive result wasn’t announced by the World Anti-Doping Agency-accredited Swedish lab until February 8, a day after Valieva and her Russian Olympic Committee teammates won gold in the team competition. An Olympic official said Valieva blamed the positive test on a mix-up with her grandfather’s medication. The skater’s coach, Eteri Tutberidze, told Russian state news agency Tass her entourage is “absolutely sure” she is innocent.Valieva was allowed to compete for more gold in the Olympic women’s individual figure skating event. Her routine for the free skate — the final portion of the women’s competition — features quadruple jumps that are untouchable by most of her competitors. Here’s how the sport has evolved in recent years to reward increased athleticism and stamina: More difficult jumps = more pointsIn 2004, the International Skating Union ditched the subjective “6.0” scoring system for the more rubric-based International Judging System that gives certain base points for jumps depending on their degree of difficulty and how many times the skater rotates in the air.For example, a quadruple Lutz — in which a skater makes four revolutions in the air — carries more base points than a triple Lutz. But a triple Lutz carries more base points than less difficult triples, such as a triple loop or a triple Salchow. After each jump, skaters can gain or lose points from the base value depending on the grade of execution — how well or poorly they executed the jump.All those numbers are part of the technical score. There’s also the presentation score, which rewards artistry and skating skills between jumps. But in recent years, skaters have been able to win competitions largely due to points racked up from jumping — with quadruple jumps playing a larger role in men’s and women’s skating. Why better stamina can win skaters more pointsIn women’s figure skating, athletes perform two routines: the short program, which is about 2 minutes and 40 seconds long, and the free skate, which is about 4 minutes long. With the current scoring system, jumps performed in the second half of the free skate can get a 10% bonus because it’s more difficult to perform them on tired legs. 2018 Olympic champion Alina Zagitova, who was also coached by Tutberidze, capitalized on this and put all her triple jumps in the second half of her free skate. The 15-year-old Russian won Olympic gold and was celebrated by President Vladimir Putin. But critics denounced Zagitova’s method of winning, saying the teen’s performance lacked artistry or relied too heavily on jumps crammed in the second half of the routine to maximize points. After the widespread criticism in 2018, the International Skating Union created a new rule saying skaters will only get 10% bonuses for up to three jumping passes in the second half of their free skate. The new rule has been dubbed the “Zagitova rule.” Since the last Olympics, women’s figure skating has been dominated by Russian teenagers such as Kamila Valieva, Anna Shcherbakova and Alexandra Trusova. All three have won international championships after adding quadruple jumps in their routines — an enormous athletic feat.Valieva became the first individual female skater to land a quad at the Olympics when she helped Russian skaters win the team event last week. But if Valieva places first after the women’s final, she might not get an Olympic medal around her neck for a while — if at all. The International Olympic Committee’s executive board said this week that there would be no medal ceremonies for the completed team event or the women’s skating competition — should Valieva place in the top three in that event — until it’s determined whether the skater had violated anti-doping regulations.CNN’s Simone McCarthy, Hannah Ritchie and George Ramsay contributed to this report.