In an interview after the upset, Katz's face is again drained of emotion, his eyes roaming the floor as he answers questions. "I didn't know what to expect," the young man says. "I was glad I was able to play a good game and come out on top."
"A lot of pressure on these young men," the announcer tells the audience as the live-cast closes down. "You have to give it up to Bread."
EA Sports, the company behind the Madden franchise, called Katz's win the "most exciting moment in all the 2017 NFL Club Series Championships." The Buffalo Bills tweeted out congratulations to Katz.
But the promising competitive Madden career Katz launched with his 2017 victory in Buffalo took a drastic turn yesterday in Jacksonville, Florida.
Authorities have identified the 24-year-old as the suspected shooter after gunfire erupted at a live-streamed "Madden NFL 19" qualifying tournament held at a busy mall restaurant. Two people were killed in the attack, Jacksonville Sheriff Mike Williams told reporters. Eleven others were taken to local hospitals, including nine gunshot victims and two people injured fleeing the scene, according to Williams. The gunman shot himself fatally, authorities said.
The investigation continues to zero in on Katz, who reportedly competed in Madden under the tag names "Bread" and "RavensChamp." Federal agents and local police raided a home near Baltimore's Inner Harbour. Neighbours said they have seen Katz there in the past.
Police have yet to detail a motive for the shooting, although Katz was registered to compete in the Jacksonville tournament, according to the event's website. A witness told the Florida Times-Union that the man allegedly opened fire after he was eliminated from the contest.
The shooting has delivered a blow to the tightknit Madden community just as the game's popularity as a spectator sport - and the stakes involved - rise in the esport universe.
"This is a competitive game," Matthew Lee, a Madden gamer who was scheduled to attend the event but did not end up making the trip, told the Washington Post. "Everybody knows each other. When things get heated, they do get heated, everybody trash-talks at events. But when the cards are down, this is a family."
Once thought of as a slacker hobby, esports have become a highly competitive - and highly lucrative - pursuit for gamers in recent years. Top-ranked players compete for prize money as well as endorsement deals, with some championships offering prizes in the millions. They spend myriad hours training to perfect their hand-eye coordination and fine-tune their ability to focus under pressure.
Some esports tournaments feature players competing in games that replicate traditional sports played by live athletes, like Madden NFL and NBA 2K. Others allow them to face off in games like "Counter-Strike" and "Fortnite," which are based on battle scenarios.
According to the esports research firm Newzoo, the worldwide audience for esports is expected to reach 380 million people in 2018. Newzoo predicts that esports sponsorships for North American teams will reach US$162 million in 2018.
A Washington Post-University of Massachusetts Lowell poll released this spring found that almost three-quarters of Americans between the ages of 14 and 21 had either played or watched multiplayer online games or competitions in the previous year.
For some young players, esports can be a way of paying for college. In 2014, Illinois-based Robert Morris University became the first college with a varsity esports program that offers scholarships to players, according to Engadget. About 60 schools have followed suit and established esports teams recognized by the National Association of Collegiate Esports, while many others have unofficial programmes, the site reported.
A little over a week ago, the University of Akron announced that it would be opening an esports facility for its varsity, club and recreational teams in October, touting it as the largest esports space at any university in the world. That same day, the university announced plans to phase out 80 degree programmes because of low enrollment numbers.
The potential financial upshot for esport competitors rivals some traditional athletics. The five-person team that won The International 2018, a "Dota 2" online battle competition that concluded over the weekend, walked away with more than US$11 million in prize money. Additional prizes for runners-up put the total prize pool at more than US$25 million.
But esports also present their own unique form of overwhelming pressure.
"There is no other sport in the world in which one day you can be a teenager playing a game by yourself, and the next day, because someone scouted you from your online account, you're thrown onto a stage for millions to criticize," ESPN esports reporter Tyler Erzberger wrote in an article on the pervasiveness of mental health issues in the esports community published at the weekend, before the shooting.
"There's little to no assimilation period. There's no road map for how to deal with the criticism. There's just you, on the stage with four teammates, facing down the biggest moment of your life with no lifeline."
Named after John Madden, a longtime pro football coach and commentator who in 2006 was inducted into the Pro Football Hall of Fame, Madden NFL allows players to build a fantasy roster for their favorite NFL team and compete in online matchups. About 46,000 people belong to /r/Madden, a Reddit community dedicated to discussing the series.
The first game in the series, "John Madden Football," was released in 1988. By 2014, sales had topped US$4 billion in revenue.
As of August 13, more than 130 million copies had been sold, the game's maker, Electronics Arts, said in a news release timed with the release of "Madden NFL 19," the latest version.
Despite Madden's long-standing popularity as a franchise, the game's status as a competitive game is a recent development, thanks to the uptick in tournaments with prize money.
Yesterday's competition was a regional qualifier for an October final round in the Madden NFL 19 Championship Series, which offers a US$25,000 prize to the first-place winner.
Three million players competed in the challenge last year, which was the top-rated esports broadcast in North America, Todd Sitrin, a senior vice-president and general manager for Electronic Arts' competitive gaming division, said earlier this month in a news release.
The release also noted that this year's competition will have a prize pool of US$700,000, the largest in the game's 30-year history.
"People don't realise Madden is a growing game in terms of esports," gamer Matthew Lee told The Post. "There are guys who are going to make over $100,000 playing this year. With streaming and partnerships on top of the prize money you can win in tournaments, it's becoming a way to make a living."
However, the circuit remains a tight group of competitors, Lee said. Everyone knows everyone else - in part because of the intimate nature of the game. Unlike other popular esports titles like "Call of Duty," where players compete in teams, in Madden NFL, it's just you working to outsmart an opponent.
"It's a mental chess match," Lee said. "I liken it to a lot of card games with the way you fundamentally have to think about it. You make educated guesses, have to quickly do the math, measure possibilities. You have to outplay your opponent based on probabilities."
The high-stakes can supercharge the emotions on the field of play.
"The Madden community is one of the most passionate and competitive groups of people you'll ever find," Michael Aldrighetti, a Madden competitor, told The Post. "During the actual game, it gets emotional. Frustrations mount, occasional chirping at each other. We're competitors going at each other. Madden may be 'just a game', but the people and the emotions are real."
At the events, however, that community is more likely to rally around members than sow division, Lee said.
"People are always helping each other," he told The Post. "Like if a guy loses a game because he didn't have a good red zone offense, then you'll have five people in a corner making sure he's ready for the next game."
Little is known now of Katz's life outside of the esports digital arena. Neighbours in Baltimore said they had seen Katz and his family members over the years but reported nothing that would predict the alleged bloodshed in Florida.
"There's nothing remarkable about them," neighbour Cameron Stearns said. "There's not anything suspicious about them at all. We have lived here for a long time, and we never talk to them."
Following his Cinderella win in Buffalo last February, Katz flew to California to compete in the Madden Club Series Championship. As the gamer faced off against Anthony "Misery" Pulli, the play-by-play announcers noticed the Baltimore native's laserlike focus on the match.
"You are not going to see much emotion from our guy Bread," the announcer commented. "David Katz keeps to himself. He's a man of business. He's not here for the experience . . . he's not here to make friends. He's all business, he's focused, and even to get him to open up to talk to you about anything, it's like pulling teeth."
Katz's Bills eventually fell to Pulli's Steelers, 17-14. "Bread fought back as well as he could but ultimately came up short," the announcer said following the defeat as a stone-faced Katz packed up. "You know that's got to be a frustrating feeling."