Lots of Bears fans can rattle off Brian Urlacher's career highlights: Rookie of the Year, Defensive Player of the Year, eight-time Pro Bowler, future Hall of Famer. But there is one achievement that won't show up in an on-air caption during an interview:

Most career box-ups.

Wait—what?

"I don't talk about boxing people up," the tight-lipped Urlacher said. "I just do it."

Though Urlacher claims he's "not going to comment on the box game with the media," who better to explain the Box Game than the career leader in box-ups?

"The object is to get a box and put it on someone's head without them knowing," Urlacher told teammate Robbie Gould on the chicagobears.com show "The Final Horn," "until the box is on their head and it's too late."

The basics of the Box Game are as follows:

1. Pull the flaps off the top and bottom of an empty cardboard box so you are holding a hollow box cylinder.

2. Sneak up behind a teammate.

3. Slam the box over his head and shoulders.

The only rule? You can't box a guy when he's naked.

ALLIANCES

Sources told RedEye the Box Game dates to at least 2007.

"It kind of just happened one day," Charles Tillman said. "I can't even remember."

What is certain, however, is the game has evolved into a brutally contested battle with alliances, truces and broken truces.

Basically, the team's two big groups—the defensive line and the linebackers—are locked in a constant struggle for supremacy and loyalty among the other units. Their lockers are in the back of the locker room, and from that position they wield influence over the rest of the participants.

Joining Urlacher and his most-career box-ups is Lance Briggs. From their place along the side wall, Briggs and Urlacher shout across the locker room at young running backs and receivers, warning them that the linebackers can protect them only if they join forces.

So far, the recruitment strategies of Urlacher and Briggs have been successful. "We help out the linebackers a little bit," said Matt Forte, arguably the offense's best boxer. "I think everybody's against the D-line because they're the big guys and they try to bully everybody with the boxes."

"When it comes to the boxing game," Amobi Okoye said, "Lak [Urlacher] is himself, and Lance does pretty good, but the D-line as a group, oh yeah. Everybody wants us."

"I don't have an alliance with them," Urlacher said of his strained relationship with the defensive line. "Those mother[bleepers] don't play fair."

"The wide receivers want to get a piece of us," Okoye said. "The running backs. The DBs. That should tell you—we're the best."

Meanwhile, the other units range from neutral and nervous (secondary), neutral and incredulous (special teams and offensive line), neutral and plotting (quarterbacks) and just plain neutral (tight ends).

When asked if he plans on remaining neutral, cornerback Tim Jennings cited his concern about the size and strength of both the D-line and linebackers.

"They've got some big old boxers," he said with a nervous laugh. "Those boxers will swallow me."

Meanwhile, Jason Campbell, speaking for the currently neutral quarterbacks, said they won't be Switzerland forever.

"We haven't boxed anyone just yet," he said. "But trust me, we see the linebackers and D-linemen boxing each other all the time, so we're gonna find a day where Jay [Cutler], myself and Josh [McCown], we can sneak in there and box somebody."

HOW TO BOX

As Okoye explained, the key to a successful box-up is "the sneak-up. The attack. The planning. The execution. It's just like playing out there on the field."

For instance, the most public boxing of 2012 came on a Friday while the locker room was open to the media. On Fridays, the room is filled, players packing up their gear for Sunday's game. Standing at his locker and talking with teammates was Cheta Ozougwu.

Ozougwu was none the wiser as Forte sneaked into the locker room clutching a box. He tiptoed behind Ozougwu, lifted the box over head of the 6-foot-2 defensive lineman, and in one swift motion brought the box crashing down over Ozougwu's head and shoulders.

It was a picture-perfect boxing, and the locker room responded with hoots and cheers.

"Keep your head on a swivel," receiver Eric Weems said with a laugh. "Don't turn your back. Once you turn your back you can get got. Anybody."

This goes for the leaders too. Israel Idonije led a sneak attack on Urlacher for the ages.

"And they caught it on film, so that's pretty bad," a giddy Forte said.

"[Urlacher's] gotten a couple D-linemen," Ozougwu said. "So we've had an eye out for Urlacher. Izzy had the good idea to go upstairs with a big box, and as soon as Urlacher came underneath the stairs he dropped it down and bam! We got him."

"Earlier today I was cheap-shotted by a box," a disappointed Urlacher told Gould on "The Final Horn." "I was walking out of the locker room and somebody stood in the platform above me and dropped a box on my head, and they started screaming 'Box him up.' "

THE RIGHT PERSPECTIVE

While the Box Game is the most intricate and heated game in the Bears locker room, there are others. The offensive line reportedly excels at Four Square. The ping-pong battles are legendary, while games such as Soccer HORSE, Laundry Basket PIG and billiards also help keep guys loose.

That's what it's all about, Okoye said.

"Football is our focus," he said. "It's definitely No. 1 when it comes to all that we do. But we just like to have fun.