Denver » From his vantage point, which is somewhere in the middle of the mayhem that is the line of scrimmage each and every NFL weekend, Broncos nose tackle Ronald Fields has an up-close-and-personal view of what makes opposing offenses go.

He knows that while the confetti, the big contracts and plenty of glory get tossed at the guys throwing the ball, if a defense cannot stop the guys running with it, a team simply cannot win. That has been the case with the Broncos the past three weeks.

"And it's embarrassing, is what it is," Fields said. "The No. 1 thing you do take pride in for a good defense is stopping the run. ... It's hurtful, embarrassing. It's not a good feeling, and no matter what anybody says or what you hear, it's one of those things that's going to be true forever."

The Broncos' past three opponents -- Baltimore, Pittsburgh and Washington -- are ranked 14th or lower in the 32-team NFL in rushing, yet they have averaged roughly twice as many yards per game as the Broncos' first six opponents did. In their 6-0 start, the Broncos held teams to 79.7 yards rushing per game. During the Broncos' three-game losing streak, opponents have rushed for 157.3 yards per game -- and the Steelers and Redskins topped 170 yards the past two weeks.

"If teams can run the ball on you, that means they can pretty much do whatever they want," Broncos linebacker Mario Haggan said. "They run the ball, that means you're not being physical, you're not being tough and you're giving them the opportunities to do what they want."

Broncos coach Josh McDaniels often has talked about successful run defense being a choreographed endeavor based on linemen engaging blockers and filling gaps while others are tabbed to make the tackles. More than once this week he has described the Broncos' recent troubles as being a problem with players "jumping around blocks."

This means players are leaving their assigned spots to try to beat the blockers to make the kind of play they believe the team needs. They instead get pinned on the wrong side of the blockers, away from the ball, and that leaves a gap for an offense to run through.

"I'm always concerned if we're having trouble stopping the run," McDaniels said. "Anytime you struggle in that phase, you got to back to fundamentals and basics and say, 'I've got to do my job, count on everybody else to do theirs.' Jumping around blocks and trying to make plays, if we've got 11 guys doing that, we're not going to have much success; you're going to open holes."

"Everybody's taking turns, [saying], 'My bad,' or letting the defense down," outside linebacker Elvis Dumervil said. "We just need to just put our mind on our mistakes and go to work. Not much to say about it. Everybody's got to be more accountable off the field, getting extra lifts in, taking care of your body, getting your mind right."

The Chargers, who play Sunday in Denver, remain last in the league in rushing, as they were when the Broncos played them Oct. 19 in San Diego.