When the Washington Nationals traded for right-handed pitcher Doug Fister on Dec. 2, the move was first reported by 18-year-old high school student Chris Cotillo. (Paul Sancya/Associated Press)

The annual baseball winter meetings don’t feel like a place for a kid. Nearly everyone in baseball, except players, spends four days jammed into the same hotel in December. There are team meetings and a trade show. Owners stroll through the hallways teeming with scouts, agents and reporters. After the day’s events are over, front-office executives mingle at the hotel bar for hours.

But this past week, Chris Cotillo, an 18-year-old reporter and high school senior from Northborough, Mass., held his own. His red sneakers stood out in the crowd of adults but, despite his age and lack of experience, he has navigated this baseball world successfully for a year.

Cotillo, not established reporters, was the first to break the news of Ricky Nolasco agreeing to a $49 million deal with the Minnesota Twins, and the trade of Doug Fister from the Detroit Tigers to the Washington Nationals. The scoops have left some executives and reporters wondering how a teenager landed such information.

What began as a hobby in 2011, running a Twitter account that aggregated Major League Baseball transactions, has turned into a fledgling reporting career. Cotillo writes for SBNation.com and is still a student at Algonquin Regional High School, about 30 minutes outside of Boston. He sleeps four hours a night, is glued to Twitter during class, writes baseball stories during lunch, and aspires to be a professional baseball reporter after college. At age 6, he staged news conferences with his stuffed animals in his room.

“I consider myself someone who wants to get to the top and figured you might as well start young to do that,” he said.

The Post Sports Live crew discusses the Nationals’ trade for right-handed pitcher Doug Fister from the Detroit Tigers for Steve Lombardozzi and two other players. (Jayne Orenstein/PostSportsLive/The Washington Post)

Cotillo grew up a Boston Red Sox fan and baseball nut. By 7, he was making his own spreadsheets of roster moves. He struggled to do homework during the winter meetings because he was chained to the news.

Cotillo got an iPhone two years ago and started his Twitter account, formerly @TradeDeadliner. He tweeted out news of roster moves without attribution. He didn't consider himself a journalist then. Through that, he built a following and then began citing others.

“People in the game [started] noticing and following it, and you start talking to a couple players through direct message,” he said. “And that inspired me, ‘Well, if players are willing to talk to me, then I might as well reach out to people throughout the game and people in the know.’”

Some baseball officials he communicated with scoffed at his age, but he was persistent. Last winter, he began reporting minor baseball news, such as teams’ interest in minor league free agents. He joined CLNSRadio.com in Boston as a Red Sox beat reporter but couldn’t attend games. In May, he began writing for SB Nation’s MLBDailyDish.com. A product of his generation, Cotillo said he e-mailed and texted “a lot” with sources and only recently began calling them.

In July, Cotillo reported part of the Marlins’ return in the Nolasco trade with the Los Angeles Dodgers. He reported the Jason Kubel trade from Arizona to Cleveland. Then, his Twitter account, @ChrisCotillo, had about 5,000 followers. Because of the recent Nolasco and Fister news, and TV and radio appearances at the winter meetings, Cotillo now has more than 17,500 followers.

Cotillo’s parents planned a family vacation at Disney World so he could attend the winter meetings, and he took four days off of school. Through SB Nation, he received a press pass for the American League Championship Series and World Series.

All week at the winter meetings, front-office officials, reporters and even his own father have wondered about Cotillo’s sources. Asked about his reporting methods, Cotillo is coy.

“Creativity,” he said, with a smile. “Social media allows me to, that’s the key to it.”

At 7:42 p.m. on Dec. 2, Cotillo tweeted that Washington acquired Fister, a pitcher the Nationals weren’t publicly linked to as a potential trade target. Twelve minutes later, Fox Sports reporter Ken Rosenthal confirmed the news.

“It was unexpected,” Cotillo said of how he scored the Fister scoop. “That’s really all I can say. People in the know.”

Cotillo had only one source for the story and, unlike more established reporters, couldn’t confirm it with a second person. He said he called his editor at SB Nation before reporting the news.

Reporters have chided Cotillo for his age, and longtime baseball writer Jon Heyman of CBS Sports teased him for going on rides at Disney World before the winter meetings began. But Heyman is impressed with Cotillo’s work.

“If there was some tell-tale sign, like if he knew somebody who had the fax machine at MLB, I might raise my eyebrow,” Heyman said. “But I don’t think that’s the case. I’ve seen him here. He’s legitimately working hard.”

Cotillo’s parents, David and Jeannie, are proud of their son but worry. They monitor his Twitter use. Cotillo gets good grades but stays up late because of baseball and homework. He is considering studying journalism at Maryland, North Carolina, Boston College, Boston University and Northwestern.

“It’s great because it’s his passion,” his father said. “He needs to be a kid first because he’s going to work the rest of his life. He’s definitely going to college. He needs more of the foundation of journalism.”

Cotillo is still learning how to sort through the agendas of agents and team officials. He is learning about journalism’s most valuable commodity — credibility — and about ethics, which includes not cheering for his beloved Red Sox, his favorite players or accepting tickets from players, which he said he once did. He is also learning how to juggle his life.

“It’s necessary,” he said. “Balancing two amazing opportunities: the opportunity to learn in school and be a normal high schooler and have a social life there, and to meet so many awesome people here.”