Five secrets of the NFL this season

Knowshon Moreno accounted for 1,586 yards from scrimmage this season. Joe Amon/The Denver Post via Getty Images

The Oakland Raiders could not stop Peyton Manning from breaking the NFL’s single-season record for passing yardage as the 2013 season concluded Sunday. Their best hope came not on the field but from the league’s official statistician, which ultimately decided against reclassifying a 7-yard pass as a rushing play. The decision allowed Manning to keep the record (5,477 yards) by the narrowest possible margin, a single yard.

The constant focus on Manning’s passing exploits is natural because he and the Denver Broncos are so proficient at throwing the ball. Manning set another single-season NFL record with 55 touchdown passes, as Denver had four players with at least 10 scoring receptions. Manning attempted a league-high 659 passes and his completions (450) outnumbered the attempts for current playoff QBs Russell Wilson and Colin Kaepernick. But as ESPN.com presents an “NFL Confidential” package beginning this week, we take a closer look at an overlooked secret to the Broncos’ offensive success. Their ground game is No. 1 on my list of five NFL secrets heading into the new year.

1. Denver is more dangerous on the ground than you think

The Broncos have dropped back to pass 56.3 percent of the time on first and second downs, the 13th-highest rate in the NFL and right near the league average (55.1). The dropback rate climbs slightly to 60.8 percent, which ranks eighth, without plays when Denver was leading by double digits and more likely to run. Though overshadowed by Manning's prolific arm, the Broncos rank sixth in rushing yards on early downs over their final seven games, up from 17th over their first nine games. Their per-carry average has spiked from 3.7 to 4.6 in the process, with Knowshon Moreno and Montee Ball providing a 1-2 punch.

“It’s easy to see Moreno and what he brings: a pads-over-toes, violent run style,” a defensive coach said. “The hidden gem is the development of Ball. He’s showing signs of becoming a tough, slashing back, which was his M.O. at Wisconsin. [Broncos offensive coordinator] Adam Gase and that staff seem to be getting them ready for winter football. They've now got a two-headed rushing attack, and both are also dangerous on short passes and screens -- smart by the offensive staff.”

Gase is drawing interest as a head-coaching candidate one year after the San Diego Chargers hired Gase’s predecessor, Mike McCoy. Most every quarterback wants to throw the ball and then throw it some more, but there have been times this season when the game plan called for something else. That was most obvious when the Broncos ran the ball seven consecutive times to begin their second drive on a cold and treacherous night at New England back in Week 12. The right game plan and the right quarterback can make life tough on a defense.

“People just assume Peyton is doing this amazing stuff in the passing game and then checking to runs, but he is doing amazing things in the run game, too,” a rival quarterback said. “They are running to the shaded nose guard or away from the tight linebacker unless the defensive end is aligned just so -- subtle nuances in the run game.”

Ball, in particular, has provided increased value since losing a fumble in that New England game. The coach I consulted encouraged me to compare Ball’s numbers since that game to the numbers for Moreno and Reggie Bush, just to get a better feel. Ball has 297 yards and a 6.6-yard average over that span. Moreno is at 214 and 4.0. Bush is at 269 and 4.3. Their roles aren’t the same, but the production is telling.

These are things to keep in mind as the Broncos get ready for what they hope will be three cold-weather playoff games, two in Denver and the third at MetLife Stadium, the site of the Super Bowl. The Broncos are going to need more than Manning’s arm.