Matt Stamey/US Presswire

In a battle of unbeatens, Darren Sharper (42) gave the New Orleans Saints a huge momentum swing. Sharper returned an interception 99 yards for a touchdown early in the second quarter, helping New Orleans beat the New York Jets 24-10. It was the first of two picks for Sharper. Week 4 leaders

By John Clayton, ESPN.com

1. Colts creating separation: Before the season, the San Diego Chargers looked like the AFC team with the best chance of clinching a division by Thanksgiving. As it turns out, the Colts are the conference's best front-runner. At 4-0, they have a two-game lead over the Texans and Jaguars, and -- unbelievably -- a four-game lead over the Tennessee Titans. What's remarkable is the Colts got off to this great start despite being almost too young on offense. Marvin Harrison is gone, and Anthony Gonzalez remains sidelined with a knee injury. Peyton Manning is off to his greatest start (four consecutive 300-yard games, 1,336 passing yards and nine touchdowns) using a rookie slot receiver (Austin Collie), an unproven split end from Mount Union (Pierre Garcon) and a rookie No. 2 back (Donald Brown).

This Kid Squad is playing beyond its experience, but the young legs are opening up new things for Manning -- more yards after the catch. Last year, the Colts ranked 11th in the league in YAC. They've been among the league leaders this year. According to Colts tight end Dallas Clark, more defenses have been playing man-to-man against Colts receivers instead of using mostly zones.

"I don't know why teams are doing that,'' Clark said. "By them playing man, though, all we have to do is make one guy miss a tackle and we can get extra yards.''

Garcon is averaging 20.7 yards per catch. Brown, the rookie runner, has a 25-yard average on five catches. And Collie is just a smart slot receiver. In the second quarter of Sunday's 34-17 win over Seattle, Manning spotted the Seahawks in man coverage and yelled at Collie to do a fade route. Collie scored a 21-yard touchdown that put the game out of reach at 21-3 with three seconds left in the half.

"I'd say out of this group, we might be getting yards after the catch as well as we ever had,'' Manning said. "That makes drives more efficient. It shortens the field.''

It also lengthens the Colts' lead in the AFC South.

2. Ravens abandoning the run: After riding a rookie quarterback (Joe Flacco) and a 37-carry-per-game running attack to an 11-win season last year, the Ravens have ventured too far away from the ground game. Sure, Flacco is a great, young quarterback, but Air Harbaugh got the Ravens into trouble in a 27-21 loss to the Patriots. The Ravens dropped back to pass 49 times (47 passes and two sacks) and called only 17 running plays. The Patriots' defense isn't like the Ravens' or Steelers' in the sense that it can completely shut down a running attack. The Pats have lost too many star players to do that. Ray Rice, who didn't even start this game, had 103 yards on 11 carries, including a 50-yard run.

The Ravens are passing the ball on 57.4 percent of their offensive plays in the first four weeks. That's not Ravens football. Though the Patriots' rushing numbers weren't great Sunday, the fact that they ran the ball 30 times took pressure off Tom Brady. If the Patriots tried to take some pressure off a future Hall of Fame quarterback by running the ball more, the Ravens might consider it advisable to do the same for a talented second-year quarterback. Because the Patriots were more committed to winning the line of scrimmage, they won the time of possession battle (34:56 to 25:04). You have to figure the Ravens will go back to the run a little more against the Bengals in Week 5.

3. Redskins' close encounters: No matter if Jason Campbell and the Redskins play good or bad teams, they are going to play in close games. In 40 career starts, Campbell has been involved in 33 games decided by eight points or less, including Sunday's 16-13 victory over the woeful Tampa Bay Buccaneers. The problem is scoring points. Sunday's game was the eighth consecutive home game in which Campbell and the Redskins couldn't reach the 20-point level.

Low-scoring home games lead to booing, and Campbell heard some boos. Campbell was 12-of-22 for 170 yards and made some horrible decisions. He threw three interceptions and was sacked three times. At the half, the Redskins were trailing 10-0. Campbell rallied the offense for touchdown drives of 74 and 59 yards in the third quarter to salvage the victory.

In the Campbell era, every game is a stress sandwich. A good team should win this game going away. In the past three weeks, the Redskins scraped by the Bucs, lost to the Lions (ending Detroit's 19-game losing streak) and barely beat a winless Rams team. The Bucs are probably going to be a two- to four-win team, and the Redskins had to scramble just to win by three.

4. Saints' Sharper edge: Putting an experienced safety such as Darren Sharper against inexperienced quarterbacks is almost unfair. Against Lions rookie Matthew Stafford in the season opener, Sharper intercepted two passes for 79 yards. In Eagles quarterback Kevin Kolb's first career start, Sharper returned an interception for a 97-yard touchdown. The Saints' 24-10 victory over the Jets on Sunday was aided by Sharper's 99-yard interception return off Mark Sanchez.

Sharper, 33, might be the defensive MVP through four weeks. He has five interceptions, including two off Sanchez. Sharper said after his great game against the Lions that he has the advantage of reading the eyes of inexperienced quarterbacks. He also credits new defensive coordinator Gregg Williams for giving him more freedom than he had when he was with the Minnesota Vikings. In Minnesota, Sharper was forced to stay back in coverage to guard against the big play, but also make some stops against the run. In New Orleans, he can read and react, which isn't a bad idea considering his résumé. Sharper has 54 career interceptions, including 10 that he returned for touchdowns. His sharp play has helped the Saints start 4-0.

5. Broncos are no fluke: The Broncos are for real. They beat the Cowboys 17-10 in what was supposed to start an impossible stretch of games for Denver. As turbulent as the offseason was, head coach Josh McDaniels made the regular season smooth. The Broncos are 4-0 and appear to be big players in the AFC playoff race. Beating the Cowboys was huge. Denver's defense withstood a last-minute drive by Tony Romo. Mike Nolan, the Broncos' defensive coordinator, totally took away the Cowboys' running attack. Like he did in Week 2 against the Giants, Romo made bad decisions. The last pass of the game was broken up by Champ Bailey. If you need to win a game, never throw on Bailey. Romo threw a costly interception in the Broncos' red zone early in the second half. That interception, which was grabbed by Bailey, might have been the turning point. Had the Cowboys settled for a field goal, they would have led 13-7.

Broncos QB Kyle Orton is doing a lot of the same things that made him a winner in Chicago. He completed 20 of 29 passes for 243 yards and two touchdowns. He might not be making spectacular plays like Jay Cutler. But he's winning. Welcome back to the playoff race, Denver.

The Redskins' Antwaan Randle El must be wondering about his role. Devin Thomas and Malcolm Kelly have moved him out of the three-receiver sets, leaving him just as a slot receiver. Only one pass went his way Sunday, and it was incomplete. … Jaguars halfback Maurice Jones-Drew has 45 touchdowns in 51 career games. No wonder he is so popular in fantasy football. He's like former Seahawk Shaun Alexander. … Browns fans were booing Derek Anderson by the second quarter, but he did provide a spark in the second half to make the Browns more competitive than they were during the first three weeks. … Bucs kicker Mike Nugent missed his first four field goals of 2009, including two in the first half on Sunday against the Redskins. Good thing he made two later in the 16-13 loss. … I wonder if Jay Cutler, who claimed he threw a harder pass than John Elway, will claim he can do a better helicopter run? Cutler spun in the air on a 5-yard touchdown run in the first half of the Bears' 48-24 victory over Detroit. Elway did his in the Super Bowl. … Expect more teams to blitz Jets quarterback Mark Sanchez because of the Saints' success in putting pressure on him with extra rushers. … Raiders running back Darren McFadden is really struggling. The Texans held him to six carries for minus-3 yards. For the season, he is averaging 3.1 yards a carry and has four fumbles in four games. … The Giants are saying Eli Manning's heel injury isn't bad. They are calling it just a bruise. … The puzzling part of the Bills' 38-10 loss to the Dolphins was that they gave up 38 points despite allowing only 86 yards passing. They were down four starters, but the injuries were in the secondary and at defensive end. Yet, the Bills gave up 250 rushing yards. Miami QB Chad Henne had only 14 completions. His longest was 18 yards.