The First Read: Biggest challenge facing each division leader at quarter mark of 2023 NFL season

*The Bills hold the head-to-head advantage over Miami, even though both are 3-1.

Can Buffalo's defense sustain this success? There was a lot of talk about the Bills' defense being more aggressive with head coach Sean McDermott taking over play-calling duties after defensive coordinator Leslie Frazier stepped away from the position. That feels like an understatement today. Buffalo has allowed just 55 points this year, and it shut down a Dolphins team that scored 70 points just a week ago. The secret to that success has been relentless pressure on opposing quarterbacks and opportunistic defenders (the Bills lead the league with 11 takeaways). The bad news is that Buffalo lost its top cornerback, Tre'Davious White, to an Achilles injury against Miami, while two other cornerbacks (Christian Benford and Taron Johnson) got banged up in that contest. Injuries plagued the Bills D last year, with key players like edge rusher Von Miller and safety Micah Hyde going down. Buffalo can’t afford the same thing to happen again. The Bills get Miller back soon -- he’s supposed to start practicing this week -- but keeping this defense formidable is vital to whatever championship dreams they hold.

Will that dynamic Ravens offense appear? It’s going to take some patience before all the hype about Baltimore’s new-look offense yields significant results. The Ravens have battled injuries all over their offense, from the backfield (J.K. Dobbins is out for the season) to the receiving corps (Odell Beckham Jr., Rashod Bateman and tight end Mark Andrews have missed time) to the offensive line (center Tyler Linderbaum's only been active for half the games). The good news is that hasn’t stopped quarterback Lamar Jackson from making enough plays to help this team win three of its first four games. The Ravens just put 28 points on a Browns defense that had been playing at an elite level. They also have a chance to get their third straight road division win if they beat Pittsburgh this coming Sunday. That would create a nice cushion for them at a time when every other AFC North rival is struggling with some type of offensive issue. The Ravens might still be figuring out that side of the football. But they’re doing enough to put themselves in an advantageous position.

*The Colts hold the tiebreaker over every other team in the division.

Can Anthony Richardson lead this team to the postseason? Like all rookie quarterbacks, there is some good and some bad that comes with Richardson, the fourth overall pick in this past April's draft. The good is what you saw in the second half of Indianapolis' 29-23 overtime loss to the Rams. Richardson used his legs and his arm to rally the Colts from a 23-0 deficit and gave them a chance to win a game that easily could’ve been a rout. The 21-year-old QB was similarly impressive in a season-opening loss to Jacksonville when his multidimensional skills once again stood out. But there also are plenty of head-scratching moments, when he’ll miss an easy throw or make a shaky decision or put his body in harm’s way unnecessarily. That’s the stuff that Indy head coach Shane Steichen has to manage now that the Colts legitimately have edged themselves into contention for the AFC South title. This division seemed to be Jacksonville’s to win when the season began. Now it’s up for grabs, with everyone sitting at 2-2 and finding reasons to feel good about their chances. For Indianapolis to get there, Richardson needs to become steadier as the weeks go by.

Will their receivers become reliable? The Chiefs have plenty of wideouts, as they kept seven on the roster coming into the season. The question is whether they can find a few players within that group who can be consistent targets for quarterback Patrick Mahomes. There was some optimism about that happening after the Chiefs blew out Chicago in Week 3. Then Kansas City faced the New York Jets on Sunday night, and reality set back in. The Chiefs wide receivers combined for seven receptions and 65 yards in that 23-20 win. You can say Gang Green's defense played a huge role in those numbers, and that unit did perform admirably. However, this doesn’t appear to be an issue that is going to resolve itself quickly in Kansas City. It took Mahomes a few games last season to find a rhythm with some new faces in his passing attack. The difference this season is that many of his targets are vastly inexperienced. They’ll have to grow up in a hurry when facing better defenses the rest of the year.

Can the Eagles continue to find their offensive rhythm? Philadelphia looked more like itself offensively in Sunday’s 34-31 overtime win over Washington, which is a positive sign for the future. Quarterback Jalen Hurts threw for 319 yards, A.J. Brown had 175 receiving yards and running back D’Andre Swift continued to look like a great addition to this offense. That wasn’t the case in the first couple weeks of the season, when the Eagles started slowly, and Hurts wasn’t overwhelming opponents in the same fashion he did last year. It’s clear now that there will be some growing pains with this version of the Eagles, especially with Brian Johnson replacing Shane Steichen as offensive coordinator. What isn’t in question is whether they have the ability to be as good offensively. They’re undefeated and still looking to play their best football. They’ll be fine.

Will Jameson Williams be a difference-maker? The Lions have been waiting for their 2022 first-round pick to break out, and now would be a terrific time. Williams only played in six games as a rookie because he was still recovering from a torn anterior cruciate ligament sustained in college. He didn't play in the first four games of this season because of a suspension for gambling, but suddenly, he's back. The hope in Detroit is that his electric speed becomes the final element in a Lions offense that already is potent. Detroit boasts a star receiver in Amon-Ra St. Brown, a blossoming talent in rookie tight end Sam LaPorta and a strong running game. If Williams can take the top off opposing defenses, the Lions are likely to run away with this division. They’ve already beaten up on the Packers in Green Bay, and it’s hard to see the 1-3 Vikings or 0-4 Bears offering much opposition.

Can Baker Mayfield keep this going? There wasn’t any fanfare when Mayfield landed in Tampa Bay, largely because it was the fourth team he’s been on in 10 months. Look at him now. The Buccaneers are 3-1 and leading the NFC South at a time when every other team is shaky. Mayfield is completing nearly 70 percent of his passes, and he’s thrown seven touchdown passes against two interceptions. Now comes the hard part. The Buccaneers will face the Lions and Bills in two of their three games after this week's bye (with the NFC South rival Falcons sandwiched in between those two opponents). If Mayfield can look good in those games, then the Bucs truly will be on to something. If he can’t, then Tampa Bay’s road to the NFC South title will be a lot more treacherous.

Can the 49ers stay healthy? This is obviously a concern for every team, but the 49ers just experienced a season that was truly rocked by injuries. The quarterback they lost in last January’s NFC championship game, Brock Purdy, looks even better now than he did as a rookie. Running back Christian McCaffrey, who’s battled his own health issues over the past few years, is playing like a legitimate MVP candidate (he scored four touchdowns in Sunday’s win over Arizona). Everything else in San Francisco looks pretty good, as the 49ers have rolled to a 4-0 start. There isn’t another team in the league that is this impressive on both sides of the football. If the Niners can avoid the injury bug, most teams are going to have a hard time beating them.

Mack didn’t have a sack through the first three games of the season. On Sunday, he reminded us that he still has plenty left as a disruptive presence. The Raiders couldn’t do anything with Mack in the Chargers’ 24-17 win, as he finished with six(!) sacks. Only five other players in NFL history have recorded that many quarterback takedowns in a game (Derrick Thomas holds the record with seven), and Mack did it on a day when fellow edge rusher Joey Bosa was hurt. The Bolts' defense has been disappointing in 2023. This was a critical accomplishment for those who believe that unit can turn things around.

It feels like a long time since Allen melted down in that season-opening loss to the Jets. He’s completed 75 percent of his passes since that day, with eight touchdowns and one interception. Sunday’s 48-20 win over Miami offered Allen even more vindication. He completed 21 of 25 passes for 320 yards and accounted for five touchdowns (four passing). The message Allen sent was impossible to miss in a huge AFC East showdown: The Bills are hard to beat when their quarterback's at his best.

The rookie wide receiver has been on fire since Week 1 and doesn’t figure to slow down anytime soon. Nacua is doing things that have never been done -- his 39 receptions and 501 yards are the most by any player in his first four games -- and he just lit up the Colts in that overtime win. Along with catching nine passes for 163 yards, his 22-yard touchdown reception won the game for Los Angeles. The Rams were supposed to struggle with Cooper Kupp sidelined by a hamstring injury. Instead, they unearthed another young star at the position.

There really isn’t a lot left to say at this stage. The Steelers have been plagued by offensive problems for most of the last three seasons, and Sunday’s loss to Houston only reinforced Canada’s inability to change that. While the Texans watched rookie quarterback C.J. Stroud light up a Pittsburgh talented defense, the Steelers generated just six points and 225 total yards against a Houston squad that entered the game ranked 22nd in the league in points allowed. Steelers head coach Mike Tomlin has been extremely loyal to his offensive coordinator. It’s hard to see how much longer that can continue, with Pittsburgh averaging 15.5 points per game.

You knew the Bengals' offense was going to struggle with Burrow playing through a calf strain. It’s just hard to imagine it being this bad for a prolonged period of time and Cincinnati contending for a playoff spot. The Bengals couldn’t do much of anything in their 27-3 loss to Tennessee. Burrow threw for just 165 yards, endured three sacks and lost a fumble on a strip-sack. To know how bad it is in Cincinnati, Burrow has tossed just two touchdown passes, and the Bengals have yet to score an offensive touchdown in the first half of a game. This is a talented team. But at 1-3, the Bengals might be digging a hole that their injured quarterback can’t dig them out of by season’s end.

To be fair, New Orleans quarterback Derek Carr is dealing with a shoulder injury that sidelined him in the second half of last week’s loss to Green Bay. The problem is this offense was anemic last season, and it’s trending that way again with Carr banged up. The Saints have only scored 20 points once in their first four games. They were flat-out awful in a 26-9 loss to Tampa Bay on Sunday, as they gained 197 yards and committed three turnovers. This team has too many weapons on offense to produce numbers like that.

The 49ers have beaten the Cowboys in the playoffs in each of the last two seasons, primarily because San Francisco has been the more physical team. The 49ers still look stronger -- they’re undefeated through four weeks -- but that doesn’t mean Dallas can’t pull off the win. The Cowboys rebounded from an upset loss in Arizona with a blowout win over New England. They also still have a defense that boasts the most dangerous defender in football (linebacker Micah Parsons) even though it lost Pro Bowl cornerback Trevon Diggs to a season-ending knee injury. Dallas will need everything it can muster in this Sunday Night Football matchup because San Francisco is the most balanced team in the league.

• Caesars odds: +500
• Weeks in top five: 4
• Next game: vs. Giants | Sunday, Oct. 8

• Caesars odds: +500
• Weeks in top five: 2
• Next game: vs. Jaguars (London) | Sunday, Oct. 8

• Caesars odds: +2000
• Weeks in top five: 3
• Next game: vs. Cowboys | Monday, Oct. 16

• Caesars odds: +2500
• Weeks in top five: 1
• Next game: vs. Cowboys | Sunday, Oct. 8

• Caesars odds: +550
• Weeks in top five: 4
• Next game: at Vikings | Sunday, Oct. 8