Mike Heimerdinger, offensive coordinator of the Tennessee Titans, peered down from the visiting coaches' box at the old Silverdome and used his radio headset to suggest a play against the Detroit Lion defense.
Instead of a response from Coach Jeff Fisher, Heimerdinger heard the urgent voice of a woman.
"Suite 305 needs more hors d'oeuvres right away!" she said.
Two weeks earlier, at the same stadium, St. Louis running backs coach Wilbert Montgomery had trouble communicating with fellow coaches because his radio frequency crackled with uninvited guests.
"We kept getting a lot of truckers talking out on the highway," Montgomery recalled of that 2001 game. "They were cutting in and out when we were trying to get people out on the field. It gets a little wacky and crazy."
The Motor City doesn't corner the market on those mix-ups. During an exhibition game in Philadelphia a few years ago, Baltimore coaches shared the airwaves with a pizza-delivery service. And George Ratterman, the Cleveland Brown quarterback best remembered as the first player to wear an in-helmet radio, got half of his instructions from legendary Coach Paul Brown, half from the police cruisers patrolling the area.
Red 23, Red 23.... There's a 211 in progress!
The headset system has gotten far more reliable since that 1956 version, of course, and teams are having fewer and fewer wireless worries these days. But things aren't perfect. Twice this season, the Rams have had to resort to the old system of having coaches on the sideline wearing headsets with cords.
"That was a mess," Montgomery said. "We were hearing the defensive calls. The defensive coaches were hearing us. It's always best for the opposing team when your headsets go down."
Dave Weisz, a spokesman for Motorola, which landed the NFL communications contract in 1999, said such problems are "very rare," even though years ago they might have been the norm.
"Some of the technology has changed," he said. "Since our involvement, we've increased some of the efficiency of the communications. Other parts of it, it's the system [the NFL] has had for years and is tried and tested."
Coaches talk to one another on a two-way radio frequency and their communications are encrypted, so neither the opposing team nor a third party with a scanner can eavesdrop. Coaches can wear a headset with one or two ear cups, depending on preference. They can have the entire staff on one channel, or put offensive coaches on one channel and defensive coaches on another, giving the head coach the option to toggle back and forth.
NFL rules say only one coach can speak to the quarterback via radio, and that coach has to be at field level. Some head coaches use a lapel speaker microphone for that.
In a league in which the slightest edge can mean the difference between winning and losing, coaches go to extreme measures to keep their strategies secret. Denver's Mike Shanahan was fined this season for lying about the nature of an injury to Jake Plummer, saying the Bronco quarterback had a concussion instead of a slightly separated shoulder. Why? Because Shanahan didn't want San Diego players going for Plummer's shoulder.
Coaches have taken to using their laminated list of plays to cover their mouths when sending in instructions. Some, such as Tampa Bay's Jon Gruden, cover almost their entire face.
There is some logic to that. Ernie Accorsi, general manager of the New York Giants, was the assistant GM with the Baltimore Colts in 1977 when the team hired Bob Colbert as an administrative assistant. Colbert was a former head coach at Gallaudet, the leading university for the deaf and hard of hearing, and was a professional lip-reader.
"We didn't hire him for that reason, but lip-reading was his expertise," Accorsi said.
In the 1977 regular-season finale, a do-or-die game against New England, Colbert trained his binoculars on the Patriot defensive coordinator and saw him mouth the words "double safety blitz."
"We got that in to [quarterback] Bert Jones and he hit Raymond Chester down the middle for a 78-yard touchdown," said Accorsi, whose team won the division and got into the playoffs with that win.
The Colts weren't using headsets at the time; the league had outlawed the practice. They were using the backup quarterback to signal in plays to Jones. But the radio technology was available.
In 1956, two Ohio inventors, John Campbell and George Sarles, approached Brown with a radio receiver they had developed, a modified version of one used in a World War II tank. Brown, always at the cutting edge, liked the idea and agreed to put the receiver in Ratterman's helmet as long as the system was thoroughly tested before it was used in a game.
Before that, Brown, who did all the play-calling, would communicate with his quarterback by rotating in "messenger guards" on each play. He figured the radio would be far more efficient.