John Walton, center, the Washington Capitals radio announcer, gets his face pushed up against the glass by players Keith Aucoin, left, and Jay Beagle during team practice at Kettler Capitals Iceplex in Arlington County. (Tracy A. Woodward/The Washington Post)

John Walton can tell you: Calling a hockey game on the radio is unlike any other play-by-play challenge. Whereas baseball gives you time to weave in homespun anecdotes between pitches, and football is eight seconds of violence punctuated by regularly scheduled committee meetings, hockey is like a rolling gang fight — frenetic and sprawling and savage for minutes on end, with the combatants rotating on the fly.

Look away for an instant, and you might miss a game-changing moment. And so will your listeners.

Basketball’s pace is close, says Walton, the Washington Capitals’ rookie radio announcer. But no team sport matches hockey for speed and accumulated chaos.

“You’re always trying to find the most concise way to describe the most action, but in a way that’s pleasing to people who aren’t there,” he says.

This makes hockey announcers such as Walton into something like the air-traffic controllers of the sports airwaves. On Saturday, for the 93rd time this season, Walton will do his speed-rap act as the Capitals play the New York Rangers in the fourth game of the conference semifinals. (WFED, 1500 AM, carries the games in the Washington area.)

Walton, 39, has been waiting for moments like this since he was 7 and his father, also John, took him to his first college hockey game in Minnesota.

He played a little, but mostly he’s been announcing games — more than 1,200 of them over the past 20 years or so. His broadcasting career parallels some of the players he describes: years of college games (Miami University in Ohio), and then a long, slow rise that included many bus trips through hockey’s gritty minor-league circuit, from Syracuse to Manchester, N.H., to Saint John, New Brunswick. What kept him going was “the dream” of calling an NHL game.

Walton was 38 and the announcer for the Hershey (Pa.) Bears, the Caps’ top farm team, last summer when he got the phone call from George McPhee, the team’s general manager. “Is this the voice of the Washington Capitals?” asked McPhee, without introduction.

Since then, Walton (and, yes, he’s been hearing “John Boy” references since kindergarten), has been the energetic, if disembodied, voice of the Caps’ up-down-and-up season. Joe Beninati, who handles the Caps’ TV announcing on Comcast SportsNet, may be the better-known broadcaster, but Walton has endeared himself to his own little fan base with passionate descriptions that put listeners on the rink’s glass.

Walton’s call of the Caps’ dramatic Game 7 overtime victoryover the defending champion Boston Bruins in the first round of the playoffs late last month has become a mini-classic. An audio clip on his blog attracted more than 11,000 hits in three days; a video with his radio broadcast synced to TV footage of Joel Ward’s winning goal has drawn more than 60,000 views on YouTube.

“The Boston Bruins now turn it over,” Walton began, his voice beginning to rise with excitement. “A 2-on-1. [Mike] Knuble coming with Ward. Knuble with a chance . . . back-hander . . . loose . . . they score! They score! They score! It’s over! Ward on the rebound. Good morning, good afternoon and good night, Boston! The king is dead. There will be a new Stanley Cup champion. The Capitals are still dancing!”

Walton says his first obligation is to provide straight-up description — who’s got the puck, what’s the score, how much time is left. He knows he has to speak quickly, but never so fast that his words tumble and collide like board-checking defensemen.

In between, crevices open in which Walton can wedge some personality. In Wednesday night’s epic triple-overtime loss to the Rangers, for example, he described the Caps’ Matt Hendrick’s booming check on the Rangers’ Ryan McDonagh in overtime as “a hit you could feel in Annandale!”

Later, as the marathon game proceeded into the night, Walton quipped, “An order up for breakfast might not be such a bad idea here.”

Still later, as two exhausted teams slogged to the finish, he observed, “The Rangers speed into the Washington zone, although ‘speed’ is a relative term at this point.”

Although more reserved in person, Walton speaks with the kind of rumble-from-the-gut voice that makes even the phrase “good morning” sound like high oratory and with hardly an “umm” or an “ahh.”

Among Walton’s fans is Beninati, the Caps’ TV announcer, who likes Walton’s enthusiasm and vocal quality. Although the game’s the same, Beninati says, describing hockey on the radio is different from what he does on TV.

“On radio, you get to be the be-all and end-all for the listener,” says Beninati. “You have to provide a thorough and complete picture of what’s going on. Your player-recognition skills have to be spot on. If you’re late with a call, you’ll be revealed on radio.” At the same time, he says, TV announcers sit in the middle of a complicated production that involves dozens of people, including a color analyst, a sideline reporter, a studio host, and graphics and replay technicians.

Walton’s working style is simple. On road games, he works by himself (the Caps produce the broadcast and buy the radio airtime, so having an away-game color analyst is deemed an expendable luxury). This means he’s on his own in more ways than one. For the playoff game last week at Madison Square Garden, renovations to the press box bumped Walton into a section of Ranger fans. Walton is 6 foot 2, but he spent much of the game on his toes, peering over and around standing spectators. He drew plenty of New York attitude when people around him heard his excited goal calls for the Caps.

“I heard a lot of things you can’t publish in your newspaper,” especially as the per-capita beer consumption rose, Walton says. He smiles. “It’s all part of the game, I guess.”

Some of Walton’s passion for the Capitals comes from the fact that he’s an employee of the team (his title is director of broadcasting). It’s important, he says, to report fairly on the game, but he’s a fan, too.

“My heart is with this team,” he says frankly. “Yeah, I get a paycheck from the team. But these are guys I travel with. These are guys I know personally. I talk to them when the mike’s not on, and I talk to them when it is on.”

He almost literally lives for hockey. He goes to every Capitals practice, watches games he’s not announcing, and blogs and tweets about hockey constantly (often in the middle of games).

Walton thinks his obsession with hockey may have contributed to his separation from his wife. “It’s tough,” he says. “It’s definitely not a very conducive lifestyle [for a relationship]. When you’re not working, you’re still working. Tonight, I’ll be in my apartment, and I’ll be watching a game and maybe tweeting about it. It’s not because I have to. It’s because I want to.”

Just the way it’s been since he was 7, he says.

When the season began last fall, he called his parents with another kind of announcement — that he’d finally chased down his dream of calling an NHL game.

“The time that the broadcast begins to the time I’m done for the night, that’s when I feel most alive,” he says. “You don’t know who’s out there, but you know someone is. And maybe someone is listening to you for the first time. I keep that in the back of my mind. I want to make sure they like what they hear.”