It's been a while since the Oakland Raiders were any good -- 14 years to be exact. They haven't had a winning record since 2002 and fell below .500 in 11 of the past 13 seasons. By many accounts, they've been one of the worst franchises of this century.

Jack Del Rio, Derek Carr and a group of young rising stars are trying to buck that trend in 2016.

Through five weeks, the Raiders have already won as many games, if not more, than they have in seven of the past 13 years. At 4-1, they're currently in a tie for first in the AFC West and look like they're on track to make the postseason for the first time since 2002.

It's been an extremely promising start for Raider Nation, but are they for real? Let's examine.

Oakland has the second-best record in football after winning four of its first five games. The Raiders' lone loss came in Week 2 against the Falcons, who now look like serious contenders in the NFC. That game turned into a shootout -- as most of the Raiders' contests do -- but Oakland was outgunned by Matt Ryan and the Falcons, 35-28.

The Raiders rebounded to win three straight against the Titans, Ravens and Chargers. The three-game winning streak is impressive, but it hasn't come against the toughest opponents. The combined record for those three teams is 6-9, and if you add in Oakland's Week 1 victory over the Saints, the Raiders' wins have come against teams with a combined record of 7-12.

Granted, not many teams have faced overwhelmingly tough schedules up to this point (outside of the Jets, maybe), but the Raiders have been very fortunate to face four mediocre teams in five weeks.

To compound that point, they have yet to win a game in commanding fashion. Only one of their victories has come by more than three points, with win No. 1 being the result of a two-point conversion in the waning minutes against the Saints. Does that make their record any less impressive? No, not really -- the NFL is filled with close games. However, it does raise concerns about the sustainability of their success.

The Raiders have the worst point differential (plus-5) of any team 3-1 or better. The 1-4 Chargers have a better mark (plus-10) than the Raiders despite being three games worse than Oakland in the standings. Of course, point differential isn't the end-all be-all determinant of a team's success, but it is telling of just how close the Raiders are to being 2-3. The biggest reason Oakland has been in so many close games is that the defense is not good. To be frank, it's one of the worst in the league.

The Raiders have allowed the most yards this season (2,263), 210 more than any other team. They're also allowing the ninth-most points per game at 27.4. Neither of those marks are particularly promising, especially when considering how much they've invested in the defense. Khalil Mack has struggled to produce (one sack) due to the number of double teams he's seeing. Sean Smith, their big free agent acquisition, struggled early but has turned it around a bit. Bruce Irvin, who was supposed to take pressure off of Mack, has just two sacks this season.

As a result, the Raiders have forced the offense to score 25-plus points each and every week. Carr, Amari Cooper and Michael Crabtree are a high-powered trio, but that sort of production is hard to sustain with success over the course of a 16-game season.

After rattling off all these negatives regarding the Raiders, it may sound like we're discussing a 1-4 team -- not one that's 4-1 and in first place. Given their record, it's blatantly obvious that the Raiders are indeed a good team.

They're fourth in total yards and fifth in points per game, which is the reason they've won four games thus far. And it's not just Carr's aerial attack that's getting it done, either. Their offense has been extremely balanced. Oakland is averaging 272.4 passing yards and 119.2 rushing yards per game, which is among the most balanced in football.

In fact, only the Raiders and Falcons have at least 1,350 passing yards and 575 rushing yards at this point in the season. Any time a team is mentioned in conjunction with the Falcons offensively, it's usually a good sign -- and that's exactly why the Raiders are one of the best on that side of the ball.

A big reason for their success this season is because of the offensive line. It's allowed the fewest sacks in the league (five), which is staggering. Donald Penn and Kelechi Osemele are both playing extremely well, protecting Carr and opening up running lanes for Latavius Murray and DeAndre Washington.

With the Chiefs up next on the schedule, the Raiders have a chance to make a statement against not only a divisional opponent, but a contender in the AFC. The road to the playoffs won't get much easier, with games against the Broncos, Texans, Panthers and Bills upcoming.

At this point in the season, it's simply too early to call the Raiders serious threats in the AFC. The offense is as explosive as any in the league, but the defense is a complete liability. They have yet to beat a team that is likely to make the postseason, which hurts their resume a bit. If they go on to beat the Chiefs, Broncos and Bills, their title will change from "fringe contenders" to "Super Bowl contenders."

Until then, they're simply a really, really good team -- not a great one.