Wesley Walls is getting tired of having to perform in NFL games every day of the week.

The 36-year-old tight end for the Carolina Panthers not only had to face the scrutiny of the fans and media on Sundays throughout the team's 1-15 season, but Walls also got his fair share of ribbing at home.

	Houston Texans quarterback David Carr has never played an NFL game, but his image has already been made for 'NFL Fever 2003.'

"You think I'm worried about playing on Sundays?" Walls said. "Bull. I'm worried about playing on Monday, Tuesday and Wednesday, because my kids and the John Madden game. They're like, 'What's wrong with you dad? What's wrong with you?' "

Ten years ago, Walls' kids -- Alexandra, now 11, and Wesley, 9 -- were once thought of as the target audience for sports video games, but things have changed. Today, the core demographic can be found at college fraternity houses and suburban bachelor pads, where men with disposable income, ages 18 to 28, allow game time to compete with bar time.

Last year, sports video games made up the largest genre of titles sold in the U.S. Approximately 30.8 million sports video games -- at prices of $40 to $50 each -- were sold in 2001, according to the NPD Group, a market research firm that tracks one of the world's fastest growing segments of the entertainment industry.

"It stuns people when you tell them (the video game business is) a $20 billion business worldwide," said Robbie Bach, chief Xbox officer at Microsoft, which invested billions to launch its new console and games in early November.

"Games used to get built by one person sitting in their garage for $25,000 to $50,000," said Chip Lange, vice president of marketing for EA Sports, which makes games like "Madden 2002," "NBA Live" and "Tiger Woods PGA Tour." "Games in this business now are built by studios of people that are hundreds strong and they come in at $10 to $15 million a pop just to get one product done."

	“	It's all about the suspension of disbelief. It's immersing yourself in a fantasy and feeling like it's real. ”
		— EA Sports founder Trip Hawkins

As the revenues continue to increase, so too do the costs. Sega, which recently abandoned its Dreamcast console and now makes only games, and Microsoft are fighting to a piece of a market now dominated by EA Sports, which owns a 50 percent share. To disrupt brand loyalty, the competitors must be able to spend as much or even more than EA, whose officials say they spend $10 million on proprietary software and $10 million to market the game, in addition to the costs of making the game itself.

Microsoft has allocated a $500 million marketing budget to promote its Xbox, as well as its games, about 40 percent of which are sports themed. Microsoft's "NFL Fever" has sold well so far against EA Sports' greatest franchise, "Madden."

It's what's inside that counts

Put Tiger Woods on the cover and it will sell, as EA Sports found out with its video game. Sports video game companies make a big deal over the athletes used on the cover of their games. But whether the athlete on the box really matters is debatable. "I don't think it's fair to say that we have average athletes on our covers when you look at Muhammad Ali (on Knockout Kings) and Tiger Woods (on PGA Tour Golf)," said Chip Lange, director of marketing for EA Sports. Woods did help, admits Bill Nielsen, sports and racing manager for Microsoft's XBox. "They literally beat (Microsoft) in (PC) sales immediately because they put Tiger on the box." But Nielsen said Tiger was the one exception to the rule. "The athlete on the cover doesn't sell the box," Nielsen said. "We've done a lot of research on it and it's critical that the athlete be recognizable, but the athlete doesn't move the product." According to Tom Nichols, Sega's sports marketing director, having a specific athlete on the box is diminished by the fact that their research shows about 80 percent of sports gamers know what game they are going to buy before they walk into the store. -- Darren Rovell

"I remember making a statement that I want the game to look like it looks on television and so a lot of what we were doing would be," John Madden said. "Madden 2002" was the 12th edition of a game that made its debut in 1989 on the Apple II computer. "And then there was a whole, 360-degree turn where television started doing the animation to make it look like a game."

Realism goes a long way in the video game industry. No amount of marketing dollars can sell a game that isn't realistic. A more accurate simulation helps generate the buzz in dorm rooms and apartments, and on Internet message boards and in magazines.

"It's all about the suspension of disbelief," said Trip Hawkins, who founded EA Sports in 1982. "It's immersing yourself in a fantasy and feeling like it's real." Hawkins, who is now CEO of game publisher 3DO, believes there is a correlation between realism and market share with the success of his High Heat Baseball game. Each year, as his game has become more true-to-life, he said he has sold more games. Still, 3DO continues to trail industry leaders EA and Acclaim, which make Triple Play and All-Star Baseball games, respectively.

"We've got this huge database that includes what kind of arm angle a pitcher has, which pitches he throws and what velocity is on his fastball," Hawkins said. "We have to adjust the velocity of other pitches and figure out how we want to affect him when he is fatigued."

Other game publishers pour through tons of research material to make it as real as possible, which ultimately could mean more sales.

"You have to do everything from making sure that the home team colors are worn in the crowd, to making sure that the number of seats in the arena are accurate and the number of sections in each arena are accurate," said Greg Thomas, president of Visual Concepts, Sega's game producing arm.

Thomas hires photographers to take pictures of arenas and sports venues around the country. He also employs gamers who are paid to play games all day on the lookout for problems and are expected to make suggestions on how the games can be improved. Even professional sports scouts are paid to critique everything from an animated player's tendencies and movement to its fashion.

"We freak out if we're watching the playoffs and all of a sudden a player changes his hairstyle or shaves his head," Thomas said. "Maybe we've modeled this big cool hair thing and now it's gone and we have to update all that stuff (for the next year's game)."

Even in tough economic times, the sports video game market continues to grow. Shares of market leader EA Sports have remained steady over the past year at around $60, and analysts predict the video game industry as a whole will experience as much as a 30 percent increase in sales this year. The sports genre figure is expected to lead the pack into the 21st century as broadband connections allow real-time, cross-country gaming to become a reality for the masses within the next five years.

"Take an NBA game with five guys in one living room in Seattle and they're the L.A. Lakers, and five guys in New York and they're the Knicks," said Dan Leahy, editor-in-chief for Game Now Magazine. "Every guy out on the court is controlled by a different person and these guys might be on headsets talking trash to the opposition. They're telling their teammates what to do and it's all done lightning quick -- no lag, no slowdown, no barriers to the experience. That kind of application would just be phenomenal."

Darren Rovell, who covers sports business for ESPN.com, can be reached at darren.rovell@espn.com