Denver Broncos faced with fumbling problem heading into Sunday's game against the Kansas City Chiefs

ENGLEWOOD, Colo. - The Denver Broncos lead the league in an exhaustive list of offensive categories: Points, yards, passing, first downs, third down efficiency.

Oh, and fumbles.

Denver's four turnovers, which included three lost fumbles, led to 17 New England points last Sunday in a 34-31 overtime loss.

Heading into Sunday's game at Kansas City, Denver has fumbled a league-leading 26 times and lost 16. That's six more fumbles and four more lost than the next-worst teams on the list.

Leading the way: Peyton Manning, who has fumbled 10 times and lost six. All that is part of Denver's minus-3 turnover ratio, second-worst among the 11 teams who own or share the lead in their respective divisions.

"Kryptonite. It's been Kryptonite so far. I watched 'Man of Steel' last night on the ride home," interim head coach Jack Del Rio said Monday, without a trace of a smile. "That's an issue, and we've got to correct it. ... Regardless of how good you are, that's the kind of thing that can really cripple you."

Even so, the Broncos are still 9-2; no AFC team owns a better record.

And, NFL teams are turning turnovers directly into points at a record rate.

So far this season, 13.1 percent of interceptions and fumbles - more than one out of every eight - have been returned for touchdowns, the highest clip since the AFL-NFL merger in 1970, according to STATS. That represents another spike in what has been a steadily upward trend over the last five seasons: 8.4 percent in 2009, 8.8 in 2010, 9.5 in 2011, 11.5 in 2012.

In addition to more than two dozen fumbles brought back for TDs, there have been 48 pick-6s through Week 12, the second-most behind only the 50 to this point in 2012.

"Any time you can score on defense, you just feel like you're giving your team an extra score. That's a score you're not counting on. The odds of winning go up that way," said Herm Edwards, a former NFL head coach and author of one of the most famous fumble return-TDs in league history while a player for the Philadelphia Eagles in the 1970s.

Edwards offered a simple theory for the rise in points that arrive off turnovers.

"Offenses take more chances with the ball in today's world, with the fact that you're constantly trying to score by throwing the ball around the yard. With the formation designs now - people spread out all over the field, five guys in pass routes - if you throw an interception, who's going to tackle the guy, an offensive lineman?" Edwards said with a chuckle. "If the receiver doesn't tackle him, you're out of luck. There's no one in the backfield except the quarterback, and you want him to make the tackle?"

According to data compiled by STATS, NFL games are averaging roughly the same number of turnovers as in recent seasons (about three per game) and quite a bit less than some seasons in the 1970s (about five per game) or the 1950s (about seven per game).

But those turnovers are carrying extra weight this season, points-wise.

Turnover-return TDs are helping fuel a jump in total scoring off turnovers - which also includes drives following an interception or fumble - to more than 10 1/2 points per game. That's a 4.4 percent increase from last season and the most since 1995.

As it is, one basic truth of the NFL is that turnover differential is a barometer for success: If a team can generate more turnovers than it commits in a particular game, a victory is more likely. That is a far better indicator of a game's likely outcome than, say, which team gains more yards or is penalized less.