We're a quarter of the way through the 2013 NFL season, and still no one has figured out how to stop the elder Manning and his 4-0 Denver Broncos.

Denver steamrolled the Eagles 52-20 on Sunday, and has now scored 179 points through four games. The near-perfect 2007 Patriots scored 148 points in their first four games, finishing with a single-season record of 589. The Broncos are on pace to end the year with 716.

Denver's 92 projected touchdowns would also blow away the 2011 Patriots' 75 TDs. And Manning is on pace to finish with 5,880 passing yards, 64 touchdown passes, and a 134.0 passer rating, all of which would set single-season records.

With a relatively weak remaining schedule, the Broncos seem like a lock for the postseason, and are the clear early Super Bowl favorites.

Elsewhere around the league:

Giant disappointment
Two years removed from a Super Bowl title, the Giants are 0-4 this season, their worst start since 1987. The Giants that year finished 6-9 and failed to make the playoffs.

The Giants have been decimated by injuries, especially on defense. They lost two more cornerbacks in Sunday's loss — Jayron Hosley and Aaron Ross — and the severity of their injuries is unknown.

Wide receiver Victor Cruz second-guessed coach Tom Coughlin after the game, and New York's tabloids have gotten an early start on the annual tradition of calling for Coughlin's head.

Kansas City turnaround
The undefeated Chiefs have already doubled their win total from last season, when they went a franchise-worst 2-14. Leading the turnaround are two castoffs: Coach Andy Reid (dumped by the Eagles after a disappointing 2012) and quarterback Alex Smith (replaced on the 49ers by Colin Kaepernick).

But the biggest source of the Chiefs' success is its stingy defense. Kansas City has allowed a league-best 10.3 points per game. Their +9 turnover differential — aided by seven forced fumbles and five interceptions — is also tops in the league.

Flightless Eagles
Chip Kelly and his rapid-fire offensive revolution were supposed to save Philadelphia. Instead, the Eagles are 1-3, their only win coming in a squeaker against the also 1-3 Redskins.

You can't blame the offense, though. The Eagles have put up the second-most yards of any team, and the run-first approach has LeSean McCoy leading the league in rushing yards, with 468.

The defense, though, has allowed more yards per game (446.8) than any other team, while giving up the second-most points per game (34.5).

Steelers, Redskins off to slow starts
Since 2000, the Steelers have missed the playoffs only four times. With an 0-4 start, they are fast on their way toward another early offseason.

Nothing is going right for them this year. The offense ranks 25th in PPG, while the defense ranks 24th in PPG against.

Meanwhile, the Redskins finally scratched out their first win of the season yesterday. Washington rode rookie QB Robert Griffin III to the playoffs last year, but have looked aimless in the early going this season as he has floundered.

In 2012, Griffin ranked third in the NFL in passer rating. He's 18th this year, and has thrown nearly as many interceptions (four) as touchdowns (six). He also has yet to learn how to slide, a failing that probably cost his team a Week 3 win.

Flacco's bad day
Ravens QB Joe Flacco, who signed a record $121 million contract to stay in Baltimore after winning the Super Bowl last year, is still playing like Joe Flacco. He threw five interceptions in Sunday's loss to the lowly Bills, and now has seven on the year, most in the NFL.

It gets worse. His passer rating ranks 27th in the game, and he has the same completion percentage as Jets rookie quarterback and emergency fill-in Geno Smith, a guy who on Sunday gave us his own take on the infamous Mark Sanchez butt fumble.