Audience members watch the 2017 Crown Championship esports finals in London. Source: Supercell

James Wingard had never thought about being a professional esports competitor. Now, the 17-year-old Los Angeles resident, who's also known as "Wings," is part of one of the world's biggest esports organizations. He's playing in a new league that boasts a $1 million prize pool — and he's doing it all on his phone with "Clash Royale." Made by game publisher Supercell, "Clash Royale" is a mobile electronic sports game that pits players in head-to-head strategic matches to destroy each other's digital towers. They use decks of cards with their own special abilities. It's all part of a booming global market for esports that research firm Newzoo expects will generate more than $143 billion by 2020. Following its 2016 launch, "Clash Royale" generated over $1 billion in revenue in less than a year and now has over 50 million daily active users, according to Newzoo. In March, some 25 million competed in a global in-game qualifier event that saw about 7,000 players move on to the next rounds. A much smaller handful was recruited for professional teams. That includes Wingard, who was recruited by esports organization Cloud9 at the end of July, just in time for the Clash Royale League debut on Aug. 20. He's now one competitor on the dozens of teams worldwide competing in virtual leagues. "I kind of just played [the game] a lot in my free time," Wingard told CNBC. "Eventually I found myself improving a lot, and I competed in small tournaments. When they announced the championship series, I qualified for it."

'More intuitive'

With many consumers tethered to their smartphones, the surging esports industry has made a strategic bet on mobile growth. Mobile gaming revenue accounts for the largest share of revenue, which Newzoo estimates will top $57 billion in a $125 billion market this year. By 2020, mobile's slice of the market could grow to over $72 billion, the firm said. While mobile gaming has been a staple in Asia, particularly with hit titles like "Arena of Valor" and "Battle of the Balls," mobile esports clocked in around 2 million hours viewed on streaming platform Twitch in North America and Europe last year. Thanks to soaring popularity, "Clash Royale" viewership took up more than half of that time. Noah Whinston, who is CEO of esports organization Immortals and fields one of the eight teams in "Clash Royale's" North American league, believes it's one of the two main factors that could result in success for the league. Whinston told CNBC that certain multiplayer games popular in Asia are "difficult to understand with the amount of champions you need to learn [and] the amount of game knowledge you need to have. "Clash Royale," however "is more intuitive to understand," he added.

Participants sit at computer monitors to play video games at the 2018 DreamHack video gaming festival on January 27, 2018 in Leipzig, Germany. Jens Schlueter | Getty Images

The second factor, he said, is Supercell's involvement in developing the league. According to Supercell CEO Ilkka Paananen, at least part of it involves crafting a truly mobile experience for players. "One of the key factors that makes a true difference is the short session time [for each game]," said Paananen, adding that "Clash Royale's tempo is a good fit for mobile. "Even if you just have a couple of minutes to spare, you can start the match."

We focus on the mobile viewing experience, such as broadcasting the games in portrait mode, and it's helping to retain viewers in broadcast. People are staying and engaged with the content. Tim Ebner head of esports, Supercell