Daniil Simkin, Standing Out, Reaching Out The American Ballet Theater principal Daniil Simkin. There was no shortage of technical prowess during an American Ballet Theater matinee of "Le Corsaire" at the Metropolitan Opera House in early June. In the central roles, the Russian stars Natalia Osipova and Ivan Vasiliev were earning thrilled bursts of applause for the height of their jumps and the speed of their multiple turns. Then Daniil Simkin, as Ali the slave, stepped proudly onstage and threw himself into a twisting, leg-scissoring jump that seemed to defy physics and gravity. The audience screamed, but Mr. Simkin, who became a principal at Ballet Theater in November, was already doing it again. And again, with the deliberate clarity of someone demonstrating an elementary move. "It's called a 540 here; I'm not sure why," Mr. Simkin said after the performance, drinking coffee and eating a sugary confection at a nearby Starbucks. Maybe I'm turning 540 degrees?  Mr. Simkin, 25, with his floppy blond hair and boy-band looks, has been known for his virtuosity since he began entering international ballet competitions at 12, eventually winning top spots at the three of the most prestigious events, in Varna, Bulgaria; Helsinki, Finland; and Jackson, Miss. He is a regular on the international gala circuit and has a pop star's following on YouTube, where he began to post videos well before most dancers knew the forum existed. Despite all this, Mr. Simkin, who is on the short side (5-8 ½, he says) and boyishly slight of build, has often been considered a niche dancer, a nimble star without the gravitas of a major performer. It took four years after he joined Ballet Theater in 2008 as a soloist to be promoted to principal dancer, and he has had to wait patiently for the Prince roles in "Swan Lake," or "The Sleeping Beauty," in which he makes his debut on Wednesday. "I was definitely a bit worried about his size when I hired him," said Kevin McKenzie, the artistic director of Ballet Theater, in a telephone interview. He had such an obvious talent, but I didn't know if it would work or be a fit. Women aren't the only ones in ballet who need to conform to body stereotypes. Leading men are supposed to be tall, with long limbs and broad shoulders. There is some reason for this expectation; men have to lift and partner women, who are several inches taller than their natural height when on point. But the issue is aesthetic as much as anything else: Smaller men may well have the requisite strength and possess every technical attribute and still find themselves confined to secondary roles, as Mercutio instead of Romeo, the Bluebird instead of Prince Desiré. Mr. Simkin is obviously used to confronting the issue. "Nobody is perfect: everyone has to deal with something," he said, slightly wearily, when asked whether being small had frustrated him. Of course there are people who prefer a statuesque big guy onstage, and I'm never going to be that dancer. My build is slight, I look young, I can't dance with just anybody as a partner. But you want to work on your weaknesses, not start having complexes. Mr. Simkin's dancing has a beauty of line and a spacious grace; even in the most whiplash-fast turns, he seems to have ample time to show the inner workings of each step. Unlike most ballet dancers, he didn't train at a professional school, but studied only with his mother, Olga Aleksandrova, a former dancer with the Novosibirsk and Wiesbaden State ballets. "He didn't have the culture of being in a group, sharing that focus," Mr. McKenzie said. To be privately trained for most of your formative years is an unusual situation. I don't think it was to his detriment, but when it's all you, then suddenly all about a company, that's hard. But Daniil understood that. He is very intelligent. In conversation, that intelligence is clear. Born in Novosibirsk, Siberia, to Russian dancer parents, Mr. Simkin speaks several languages, reads widely and is fascinated by technology and social media. On his Web site, an essays section covers topics like Twitter, branding for dancers and his obsession with anime. "Nowadays we have the possibility of connecting with the audience directly," he said. So many people think of ballet as old-fashioned, but we, the new generation, are able to fix and change that.