ST. JOSEPH, Mo. -- Before Kansas City Chiefs cornerback Sean Smith ever opened his mouth, his eyes darted to his left to find a pair of shoulder pads, discarded by receiver Dwayne Bowe, crashing into a nearby equipment cart. Smith thought he was taking time after a recent training camp practice to talk to a reporter about the league's latest hot topic -- the new emphasis officials are placing on defensive holding and illegal contact -- but he quickly became part of an improvised skit engineered by Bowe.

As Smith curiously watched his teammate, Bowe struck the stereotypical journalist pose: right hand clutching a fake microphone, left hand rubbing his chin, his eyes burrowing in on Smith in hopes of detecting the truth. Finally, Bowe asked the question that summarized what every NFL receiver must be thinking these days: "So you know you can't put your hands on me anymore, right?"

Kansas City's Sean Smith was flagged for holding once Thursday against Cincinnati's Brandon Tate. John Rieger/USA TODAY Sports

Smith tried to muster a clever response. He said Bowe was so good it didn't matter if the league created even more advantages for offensive players. All that did was encourage Bowe to deliver more one-liners, to tease Smith a little longer, to drive home the point that he was living on the right side of the NFL's perceived line of fair play. What Bowe seemed to be saying was that receivers are about to have a lot more fun on game days. Defensive backs, on the other hand, had better get ready for a much tougher job when it comes to defending the pass.

This is the logical consequence of the league's openly stated approach to governing pass defense these days. When training camps opened in late July, word trickled out that officials had been instructed to crack down on defensive holding and illegal contact. The belief was that those penalties had been called so seldom in recent years that it was time to return the NFL to its rightful nature. In other words, a league that already has slanted the game toward offense -- most notably by fining and suspending defenders for hitting defenseless receivers -- apparently thinks it's essential to make it even easier to throw the football.

Critics of this edict point to the Seattle Seahawks' 43-8 win over the Denver Broncos in Super Bowl XLVIII as evidence of what the league doesn't want to see. Denver came into that contest fielding the most prolific passing offense in NFL history and left dazed and confused after being manhandled by a dominant defense and physical secondary.

"The game is definitely more exciting when the football is flying around, and I don't know if some people liked seeing [what happened in the Super Bowl]," said Smith, a sixth-year veteran who is fighting to reclaim his starting job from last season. "But it will be really interesting to see what happens once the season begins. A lot of people have a hard time with change."

Said longtime NFL referee Ed Hochuli, "The players will get it. They understand the rule changes, and they adjust. I know that the players always test us to see if we really mean it, and how far the rule is going to go. ... I would expect that there may be more fouls in the first preseason [game] than will be called in the first regular-season game because the players will have adjusted to it."

Teams already are learning how seriously officials are taking their marching orders. When the Green Bay Packers had an officiating crew in to monitor their practices in training camp recently, Hochuli said flags were thrown on the first 10 plays of a one-on-one drill between receivers and defensive backs. Most people interviewed for this story wonder whether the early-season games will produce a similar sight. The league is filled with so many talented quarterbacks and athletic receivers that holding, tugging and yanking on jerseys had become acceptable methods of defending the pass.

To understand how much the landscape had changed over the past decade, consider this: Officials called illegal contact -- which means defenders can't legally touch receivers more than 5 yards beyond the line of scrimmage -- only 38 times last season. Heading into the 2004 season, when the league also stressed enforcing this rule more frequently, that number spiked to 130. That means a lot of defensive backs have cultivated habits that need to change quickly, and their coaches already are training them in unique ways.

Officials have been told to call penalties on passing plays without regard to how it will affect game flow. Doug Pensinger/Getty Images

For example, the St. Louis Rams have told their defensive backs to hold tennis balls in their hands while covering receivers in portions of practice. Once the quarterback attempts a pass, they can drop the balls and make a play. The Cleveland Browns have gone a step further, as their defensive backs have been wearing kickboxing gloves to eliminate the temptation to grab. Pro Bowl cornerback Joe Haden missed an interception in one practice because his fingers weren't free to catch the ball.

The response to this new emphasis predictably has been strong on both sides around the league. Atlanta wide receiver Julio Jones said, "This helps us tremendously, man. Because of the speed and the size we have here with the Falcons -- and there are a lot of receivers in the league, as well, that have great speed and size -- it's going to help us out because those guys hold us."

Naturally, defensive players see it differently. Even though there will be greater emphasis on calling offensive pass interference, too, defenders realize they're competing in a league that last season saw several offensive records set, including average passer rating (86.0), combined passing yards per game (471.2) and total passing touchdowns (804). When asked how cornerbacks will contend with Detroit's 6-foot-5, 236-pound Calvin Johnson, Cincinnati's 6-4, 207-pound A.J. Green or Chicago's 6-4, 230-pound Brandon Marshall without the benefit of a savvy hold or nudge, Broncos defensive coordinator Jack Del Rio jokingly said, "You mean, how do you defend players who already are impossible to defend? That's a great question."

Said Pittsburgh Steelers cornerback Ike Taylor, "As a cornerback, you've just got to be more of a technician when it comes down to playing. If you hold too long, you know they're going to call it."

Browns defensive backs have practiced while wearing kickboxing gloves so they can't grab receivers. AP Photo/Tony Dejak

That reality is going to be even harder to accept for teams that rely on a high-pressure attack to fuel their defense. The Seahawks, Jets, Browns and Chiefs are just a few of the squads that rely on physical cornerbacks who can rough up receivers at the line of scrimmage. "We have two great edge rushers [outside linebackers Justin Houston and Tamba Hali], so if I can hold a receiver for just a second, then the quarterback has to look the other way," said 6-3, 218-pound Smith. "If the other cornerback is doing his job, then the quarterback is going down. It used to be that you could square a guy up and get a little nudge in. That's over."

Indeed it is over. So far this preseason, in 17 games, there have been 53 penalties for defensive holding, 27 for illegal contact and 15 for pass interference. Some observers might argue that even officials need to be prepared to adjust.

"We've always taught our players to play with the technique that's within the rules," said San Francisco 49ers defensive coordinator Vic Fangio. "The officiating has been instructed to be more diligent in that area. We saw a negative with that [in Thursday's game at Baltimore]. ... They called us for an illegal contact penalty, which in no way, shape or form was an illegal contact penalty. And the league's already confirmed that it wasn't. You hate to think that these guys have been drilled into their head that they're seeing ghosts out there now, too. ... We hope that stuff gets cleaned up by the time the regular season comes."

Most people around the NFL understand that this stuff goes in cycles. When the league created the illegal contact rule before the 1978 season, the target was obvious. Aggressive cornerbacks such as Pittsburgh's super-sized Hall of Famer, Mel Blount, were rag-dolling receivers at will, to the extent that the NFL said defenders couldn't touch receivers more than 5 yards beyond the line of scrimmage.

With emphasis being placed on downfield contact, A.J. Green and other big WRs have a larger edge. AP Photo/David Kohl

Passing in the NFL never looked the same after that radical decision.

The problem, however, is that officials historically have called illegal contact and defensive holding with lesser frequency until something dramatic forces the league to focus on those rules more. When New England manhandled Indianapolis' receivers in the 2003 AFC Championship Game, Colts president Bill Polian complained that the Patriots were getting away with overly physical play. The league responded by emphasizing illegal contact the next year, and Peyton Manning threw 49 touchdown passes on his way to an MVP season. That emphasis gradually declined until this preseason.

Former NFL official and current ESPN "Monday Night Football" analyst Gerry Austin said, "When the NFL looked at video of last season, they saw defensive backs riding receivers for more than 5 yards. It seemed that defensive backs were jamming the receivers for longer and disrupting routes more frequently. In the first three weeks of last season, passes accounted for 70 percent of the plays, and it appeared that there was more grabbing. The league wanted the defense to know where the 5-yard area is supposed to be."

Austin also acknowledged that defensive holding and illegal contact are two of the trickier rules to call during games. When it comes to defensive holding, the challenge is for the official to see the hold and then look back to see whether the quarterback is actually throwing the football in the direction of the receiver being held. As Smith said, "It used to be that if the ball wasn't coming your way, then the ref would just say, 'Watch the hold.' You could live with that."

Illegal contact added a third dimension to controlling the action. Not only did the official have to watch for contact but he also had to determine where the quarterback was throwing the ball and whether the contact happened beyond the 5-yard area. "The rule isn't that it's a foul before 5 yards," Austin said. "It's that it's a foul after 5 yards. So as an official, you go 5 yards plus 1 before making the call. You can't be looking at the ground and the player at the same time, so that extra yard helps. I've heard some officials say they give a defender a healthy 6 [yards] before throwing a flag. The league wants that healthy 6 to go away."

The idea of the "healthy 6" partly explains why Seattle had so much success stifling opposing offenses last season. The Seahawks didn't field the league's best defense -- one that allowed a league-low 172 passing yards per game -- solely because they had three Pro Bowl players in their secondary. They also believed they could push the boundaries of fair play because officials didn't want to slow the game down by calling too many penalties.

The success of Richard Sherman and Seattle's tough DBs likely factored into the crackdown on contact. Kirby Lee/USA TODAY Sports

In fact, many people already are calling this new emphasis "The Legion of Boom" rule, a reference to the nickname bestowed upon the Seahawks' vaunted secondary.

"That's a beautiful thing," Seahawks head coach Pete Carroll said. "That's respect to me. If that's the conversation, then it's a sign of respect and people trying to figure it out. I think we've contributed to that."

Carroll said he believes his team already is making the necessary adjustments to compete with a stricter application of the rules. As Pro Bowl safety Earl Thomas said, "We're not playing timid. We're going to stay on the attack." One thing that isn't likely to change in the wake of the league's crackdown on these rules is the trend toward finding bigger cornerbacks who can thrive at this level. The success of Seattle's secondary -- which was largely predicated on the brilliance of long defenders such as 6-3, 195-pound Pro Bowler Richard Sherman -- meant even more teams would be seeking similar athletes to help their own franchises.

Said Del Rio: "It's still important to find those players. We always want big, fast guys who can run and cover, but at the end of the day, you just need guys who can run and cover."

As for the impact on the field, most teams are taking a wait-and-see approach. Steelers defensive coordinator Dick LeBeau said, "We just hope they go with a level playing surface and [the receivers] can't grab us."

Haden added: "The thing is, we've got to take the coaching that they're giving us right now to just make sure we do our work in the first 5 yards. We've been working on that every individual [period] ... making sure we put our hand on receivers and then, after that 5, you've got to get off of them."

That was the attitude around the Chiefs as they worked their first training camp with officials in town to educate them on the new emphasis. Smith and Pro Bowl safety Eric Berry admitted that officials called numerous penalties, and at one point, after breaking up a pass, Smith looked back at one official and complained, "There's no way that was a hold." It was a comment he might utter a few more times in the coming months.

"We'll see what happens in these first few games," Smith said. "There will be flags flying all over the place, and the game could grind to a halt. And whether you're a bigger cornerback or a smaller one, you'd better work on your footwork and your technique. If you can't use your feet out here, with the way the game is going, you're going to be dead."

ESPN NFL Nation reporters Scott Brown, Pat McManamon, Rob Demovsky, Terry Blount, Jeff Legwold, Vaughn McClure and Bill Williamson contributed to this report.