The most troubling incident in the broadcasting career of John Madden was trying to find him a size 52-long blue blazer. Once a couple of CBS aides found the garment--one of the largest carried by one of New York's "he-man" shops--they stitched on the network patch and the rest was easy.

Since he quit coaching the Oakland Raiders and started working for CBS five years ago, Madden has proved himself the most enlightening, entertaining color commentator in football. His peers on the other networks are always quoting him. The burly, red-haired coach with the three-pound Super Bowl ring quickly ascended to CBS' top rung with Pat Summerall and is said to earn close to $500,000 a year since renegotiating his contract last year.

Madden has developed as potentially pedantic tool as the telestrator ("Magic Pencil") into a painless way to dissect the elaborate movements in the trenches and the secondary. Although his draftsmanship is at the finger-painting level, his frantic sketching on the screen informs without boring us into a midday snooze. (The device also brings back pleasant memories of the old "Winky Dink" show in which kids were invited to put a plastic sheet on the screen and help draw the cartoon. Madden claims he knows nothing of "Winky Dink" but what coach ever admits to copying from his colleagues?)

Madden came into the TV business unrehearsed. "They never showed me any tapes," he said on a recent visit to Washington. "They never had me practice anything. They just said be yourself."

Well, networks are always telling ex-jocks and ex-coaches to be themselves for fear they will clam up or turn into grim analysts. In this case, the advice was prescient.

"The only thing they told me to do was keep it simple," said Madden, who has taught a course in football appreciation at Berkeley. "They were wrong. People are more sophisticated about the game. They want to know why things are happening. They want to know why the quarterback's moving his foot while he calls the signals, or why a defensive back lets a man go and moves off to another receiver."

Best of all, Madden combines the ebullience he demonstrates in his beer commercials with the intelligence he showed coaching one of the NFL's most successful teams.

"Yeah, it's not that serious," Madden said. "It's not brain surgery they're doing out there. We're not curing anything. It has to be fun or why bother?"

Folks are always interrupting Madden's meals to tell him he's the best thing to happen to television since the mouse beaned Krazy Kat with a brick. He is probably in closer contact with his audience than most announcers, who generally commute to games by limo and jet.

Madden hates flying and usually takes the train, logging more than 100,000 miles a year. Once he discovered he could not get a train from Atlanta to Las Vegas, so CBS rented Dolly Parton's bus for the round trip. But usually the train suffices. When we met in Washington, he was getting set for a 19-hour rail trip to Meridian, Miss., and then a 15-hour drive to Irving, Tex., for a Cowboys game.

"There's no train into Dallas from this direction," Madden said. "That's all right. I hate flying and the train has room to move around in. That's what I need. I guess you could say I have a lot of quirks. When I heard about those people trapped in the elevator at the World Series, I could sympathize. That would be the ultimate nightmare for me."

Although he is seen by millions every Sunday on television, he cannot wait for a photographer to get his work done and be gone. "I just can't concentrate with that going on," Madden said. "On TV, I never got nervous. I guess I never knew any better."

As a commentator, he is as frank as he is poised. "What I try to do is be honest," he said. "The thing I hate is when I hear someone covering up. I mean, with the officials. They say they do a good job. But a good job compared to what? Compared to excellence? No way. The problem is, they aren't full time. Everyone else in the NFL is, but not them."

As a coach who left the game voluntarily after 20 years, Madden is a rarity. He said he originally planned to take a year off, but wound up bored. "I can't sit still," he said. "A few days in one place and I have to go somewhere else."

Although CBS thinks it has a proven winner in its top color spot, it may eventually have to vary Madden's itinerary to keep him on the train.

"I've always wanted to do a sort of Charles Kurault or Steinbeck's 'Travels With Charley' kind of thing," he said. "When and how, I don't know. But it would be traveling around and seeing sports all over the country; maybe some offbeat things. Maybe the horseshoe championships in Omaha or the frog-jumping contest in Calaveras County. Who knows?"

In whatever capacity, it will be nice to have Madden's good humor and sturdy presence on the air. May they always stock his blazer.