The video game Fortnite has had an explosive several weeks, topping Apple's charts after its iOS debut, getting lots of love from rappers and NBA stars, and holding a promising new kind of eSports event, featuring one of its biggest stars.Fortnite has become the biggest cultural breakthrough for a game since Pokemon Go sent hordes of people into the streets in 2016. That game quickly became a billion-dollar franchise, and Fortnite appears headed the same direction.According to Superdata Research, it's already the biggest free-to-play game ever on consoles, both in revenue and monthly average users. Last week, Superdata estimated the company generated $223 million in March across PC, Xbox One, PlayStation 4 and iOS.More generally, the Battle Royale format is taking off across the industry, and with luck, it may provide the impetus for a new kind of eSports tournament as well.Players Unknown Battlegrounds helped popularize the 100-player, everyone-against-everyone format when it emerged last summer as an indie PC title.PUBG featured great gameplay mechanics but cruddy graphics. It also was vulnerable to cheating (the  Chinese government just arrested and fined 15 people $4.5 million for selling cheat codes and harvesting player data).But PUBG was quickly eclipsed when Epic (partly owned by Chinese giant Tencent) spun off a standalone Battle Royale format out of Fortnite. The standalone Battle Royale version debuted as a free-to-play title on consoles and PC, undercutting PUBG's $30 price and more limited availability.Earlier this year, Fortnite overtook PUBG in Twitch viewership, according to Superdata. Fortnite's weekly unique viewers hit 14 million by mid-February, compared to PUBG's 8.7 million.And it's been Fortnite players setting viewership records on both Twitch and YouTube, according to Tubular Labs, which tracks 4 billion videos across all the major social-media platforms.Drake sat in on a game with Fortnite star Ninja (a.k.a., Tyler Blevins), grabbing a Twitch record 638,000 simultaneous views, (and 19.7 million subsequent views, Tubular found). Over on YouTube Gaming, Spanish gamer elrubiusOMG set another record with 1.1 million live viewers of his “Torneo de Youtubers” match against 99 other YouTube players (and 14.3 million more views since then).Ninja also topped Tubular's list of the five most-watched Fortnite videos. His "32 Kill Solo Squads!!" video has racked up 24 million views on YouTube as of the end of April.And on April 21 in Las Vegas, Ninja took part in an event that may represent the next step in eSports.He was the star of a first-ever Fortnite eSports tournament, taking on more than 200 other players in a series of nine matches that represent a novel and promisingly democratic new approach.The tournament, which launched the Luxor Hotel's new eSports pavilion, included a mix of top pros, up-and-comers and some just-plain-dudes willing to put up $75 for the chance to recoup considerably more than that ($2,500 for winning a match, $2,500 for killing Ninja, who like everyone else was anonymized within the game).For at least one of those unknown players, the tournament proved a huge win. A Los Angeles teenager who played only under the name "Blind" actually won a match and killed Ninja in another. More importantly for Blind, he soon was fielding inquiries from pro teams, even as he maintained his anonymity.Battle Royale matches present all kinds of headaches for eSports organizers. Unlike the team-based titles that have dominated much of eSports – League of Legends, Dota2, Counterstrike: Global Offensive, Starcraft 2 – Fortnite is 100 teams of single players, scattered across a large map. Luck, landing spots, cover, and much else play a big part in success.The resulting chaos makes for fantastic gameplay. But it also scatters the possible focus for operators of an eSports broadcast, as was seen in a first try at a PUBG tournament last fall in Oakland, Calif. PUBG will try again with another tournament this summer.In the meantime, the Las Vegas Fortnite event suggests a promising new structure for eSports success.In fact, I'd call it the eSports equivalent of the U.S. Open tournament in PGA golf. Even local club pros and young amateurs can play their way into that tournament, one of the four "majors" in the PGA schedule each year. The structure makes for occasional great real-life stories of overachievers. The 1996 Ron Shelton movie "Tin Cup" was even built around the fictional story of a talented but troubled local trying to play his way past his demons and into the Open.As eSports grows in power and reach and money, giving the Walter Mitty players a shot to play with the pros could be a difference maker in taking the fast-growing industry up another notch.And given Fortnite's success, there will be plenty of competition for its already huge fan base.Another Battle Royale title, H1Z1, just announced its coming to PlayStation 4, and already has launched a closed beta mode. The game is also free-to-play, and adds a vehicle component.Big publishers such as Activision Blizzard, Warner Bros. Interactive and EA almost certainly will try to grab some portion of this market too, though they risk being very late to the game.Given Fortnite's head start, the biggest battle all these challengers will face likely will be moving beyond niche player status in a booming business. Perhaps the all-comers contest can unlock even more opportunities for everyone.