Carson Wentz is making the second-year leap. After getting off to a bright start during his 2016 rookie campaign, Wentz spent most of the season struggling. From Week 5 on, Wentz's Total QBR (46.7) and passer rating (74.3) were roughly similar to that of Brock Osweiler, who posted a 47.7 QBR and 71.1 passer rating over that same time frame. As good as the second overall pick looked during Philadelphia's 3-0 start to the season, Wentz needed to correct some issues in his game to emerge as the quarterback Eagles fans desperately wanted him to become.

A year later, it looks as if Wentz might be the best quarterback on a rookie contract in football. He's off to a wildly impressive start in 2017, as the North Dakota State product is fifth in the league in QBR, eighth in adjusted net yards per attempt, and ninth in passer rating. Wentz enters Thursday night's game with the Panthers as the focal point of the league's sixth-best offense.

So, is this real?

The improvements

Wentz's biggest weaknesses in 2016 haven't been a problem this season. Run through the most frustrating elements of his rookie campaign and you can see how he has stepped up:

The interceptions. Wentz's interception rate wasn't necessarily an issue last season, as he threw 14 picks on 607 attempts. That's a 2.3 percent pick rate, which was identical to the league-average rate. You'll take that with a rookie quarterback, even if Wentz was throwing relatively short passes. Wentz also had five interceptions dropped, which was tied for the sixth most in the league.

Instead, the concern was that most of Wentz's interceptions seemed to come on the same sort of pass. He repeatedly sailed throws over the middle of the field to his receivers (most frequently Zach Ertz), creating easy picks for opposing defenses. Interceptions like this Andrew Adams pick or this Ha Ha Clinton-Dix nab were too common for comfort.

Wentz was one of the worst quarterbacks in the league throwing between the numbers in 2016. He threw 11 interceptions on passes in that range a year ago, which was the second-worst total in the league. Seven of those throws came in the narrow space between the hashmarks, which was the highest figure in the league. Wentz's 82.9 passer rating on those throws between the numbers ranked 27th, ahead of only Osweiler, Case Keenum and Ryan Fitzpatrick.

The 24-year-old has been a different quarterback altogether inside the numbers in 2017. Wentz has thrown one pick on 95 attempts in that range, on a screen that was tipped at the line by Chiefs standout Chris Jones. Through five games, Wentz is 62-of-95 for 674 yards with five touchdowns and a pick inside the numbers. His 99.2 passer rating on those throws is good for 14th in the NFL, while his 84.1 QBR ranks seventh.

Carson Wentz and the Eagles are off to a 4-1 start, but they started 3-0 last season and finished 7-9. Can they keep their pace? AP Photo/Matt Rourke, File

Wentz has thrown only three picks in 177 attempts. Two were tipped at the line, with the aforementioned Jones pick accompanied by a Ryan Kerrigan pick-six that was deflected at the line of scrimmage in Week 1. Wentz's only downfield interception came last Sunday, when he had Ertz open on a switch verticals concept, only for Antoine Bethea to read the play perfectly and sprint out of center field to pick off the pass. Wentz did stare down that side of the field the entire time and overthrew the pass, but if he can keep mistakes like that down to one per month, he'll be just fine. He also has only one dropped interception so far this season.

One concern might still be Wentz's propensity to fumble. In 2016, he racked up 14 fumbles in 16 games, which tied him for the league lead alongside Carson Palmer. Nobody else in the league had more than 10. The second-year starter has four fumbles through five games this season, putting him on pace to finish with ... 12.8 fumbles. If Wentz can keep his interception rate below league average and cut down on his fumbles, he'll be in great shape.

The lack of big plays. Wentz wasn't able to push the ball downfield as a rookie. His average pass traveled just 7.3 yards in the air, which was 26th in the league. As a result, the average Wentz pass attempt generated only 6.2 yards, which was second to last among qualifiers.

It was a double whammy: Wentz rarely threw downfield and wasn't very good when he decided to take a shot at a big play. He was 27th in terms of the frequency with which he threw the ball 15 or more yards downfield, and those throws produced a passer rating of 58.8, which was also 27th. Wentz's completion percentage on those passes was 26th and his interception rate was 23rd. And while there were concerns about Wentz's receivers failing to bail him out, his drop rate on those throws was 3.1 percent, which was below the league average of 3.9 percent.

Things are better this season. On passes traveling 15 yards or more in the air, Wentz's 110.5 passer rating ranks ninth. He is typically throwing far deeper, as his average pass is traveling 9.6 yards in the air, the third-highest rate in the league behind Deshaun Watson and Jameis Winston.

Watching Wentz on a week-to-week basis, I have to admit that the tape on these deep passes hasn't always been quite as impressive as the numbers. I wrote about Wentz missing a pair of long touchdown passes to Torrey Smith in Week 1, and he has missed a number of open receivers for big plays as the season has gone on. In Wentz's defense, Smith also has had a number of notable drops; the duo appears to still be working out the kinks, which isn't a surprise for a new receiving combination.

The good news is that Wentz's best deep balls of the season came against the Cardinals in Week 5. Both throws were relatively similar, as Wentz beat a big Cardinals blitz on third down against a Cover 0 defense. First, Wentz finally hooked up with Smith for a 59-yard touchdown. The deep post was slightly underthrown -- you can see Smith slow down to bring it in, and he probably would have been tackled had Justin Bethel not slipped just before he caught the pass -- but the throw was certainly good enough to give his receiver a chance to make a play.

The better throw of the two was a pass to Nelson Agholor for a 72-yard touchdown on third-and-19. This is a perfect pass, with Wentz hitting Agholor in stride and allowing his slot receiver to keep all of his momentum, which creates the cutback opportunity for Agholor to steal Budda Baker's soul after the catch.

Wentz has 10 touchdown passes and three interceptions this season, and he ranks third overall in Total QBR (69.2). Photo by Mitchell Leff/Getty Images

Struggling against blitzes. It was downright suicidal for a team whose coverage problems are as bad as Arizona's to sell out and play with no deep safeties on a pair of third downs, but an aggressive blitz might have been a smart tactic against Wentz last season. He wasn't effective when teams sent extra rushers in 2016. Wentz's 76.2 passer rating against blitzes was 26th among qualifying quarterbacks. When teams sent big blitzes with six or more defenders, Wentz couldn't make defenses pay; his 36.3 passer rating on those plays was 29th, ahead of only Colin Kaepernick among qualifiers.

As you can probably suspect, Wentz has been far better against the blitz this season. He has posted a 94.3 passer rating against all blitzes and, buoyed by that Cardinals game, a 120.5 passer rating when teams have sent six or more rushers. It has been only 15 dropbacks, but Wentz is 7-of-13 for 106 yards and two touchdowns in those situations.

The breakout

Wentz has fixed a lot of his problems from a year ago and improved on places in which he was mediocre. Where, though, has he excelled?

Third downs. You've probably read about how impressive Wentz has been on third down. His numbers are remarkable: Wentz is 37-of-52 for 574 yards with six touchdowns and one interception on third downs this season. That's good for a 96.1 QBR, which no quarterback has topped through the first five weeks of the season since Peyton Manning posted a 96.3 QBR on third downs through Week 5 of the 2006 season. Remember when Wentz was in a neighborhood with 2016 Brock Osweiler earlier? The 2006 version of Peyton Manning is a much nicer ballpark.

Wentz's third downs have been good for a 137.8 passer rating this season. Pro-Football-Reference.com has third-down statistics going back through 1994. Just three quarterbacks over that time frame have posted better passer ratings on third downs through five weeks with 45 or more attempts to their name. It's a good group, too: Drew Brees, Ben Roethlisberger and Brett Favre. Brees' 149.9 mark from the first five weeks of the 2011 season blows away the competition, but there's nothing wrong with being within spitting distance of a Hall of Famer at the peak of his powers.

Watch Wentz on third downs and you see him consistently getting the ball out quickly from clean pockets. Teams haven't been able to sack Wentz on third down; the league average on third-down passes is 9.4 percent, but Wentz is being taken down only 3.4 percent of the time, the third-lowest rate in the league. Wentz was sacked 7.4 percent of the time on third down in 2016. He's also averaging just 2.48 seconds before getting rid of the ball, which is ninth best in the league on third downs.

The Eagles are 2-0 in the NFC East with an advantage over their rivals. Photo by Mitchell Leff/Getty Images

As you might suspect, the Eagles have been great on third downs this season. Philly has converted 53.4 percent of its third-down attempts, which is the best rate in football and one of the best rates in recent history. They've also been remarkably good on third-and-long, going 11-of-26 (42.3 percent) on third-and-10 or more. Only the Chiefs (42.9 percent) have topped that, and that's in only 14 attempts. Philadelphia has gone three-and-out a league-low 13 percent of the time.

In the red zone. Wentz wasn't particularly effective as a red zone quarterback in 2016, which some might attribute to a lack of viable red zone threats beyond Ertz. He posted a 90.0 passer rating, which sounds solid but is good for only 21st in the league, just below Blake Bortles. Wentz threw 12 touchdowns against one pick, but his QBR was a mere 35.8, which was 27th among the 30 qualifying passers. He barely trailed Osweiler (36.9) in that comparison.

This season, though, Wentz has been great operating in the confined space of the red zone. He has thrown only 23 passes, but Wentz already has tossed seven touchdowns on those throws. He is seventh in red zone passer rating (111.6) and sixth in QBR (90.0). And while the 2016 version of Wentz fumbled twice, threw an interception, and took three sacks in the red zone, the 2017 Wentz doesn't have any of those blemishes to his name so far.

Knowing when to run. Nobody doubts Wentz's athleticism, but he has had to refine his instincts on when to get out of the pocket and make a play with his legs as a pro. In 2016, Wentz posted an 81.1 passer rating inside the pocket and was sacked on 4.6 percent of his dropbacks. When he made it outside the pocket, though, Wentz's passer rating dropped to 64.8 and his sack rate soared to 9.1 percent. Most quarterbacks see their passer rating drop once they leave the pocket, but Wentz seemed to be one of the few quarterbacks capable of truly scaring teams if they weren't able to contain him.

He's much improved on the run in 2017, posting an impressive 97.6 passer rating inside the pocket and an even more promising 99.4 passer rating on throws outside the pocket. We're talking about only 14 attempts, so it's still a small sample, but there's no notable drop-off this time around. Wentz is also staying inside the pocket more frequently, which is a testament to both his comfort in moving within the pocket and the improved pass protection which has come with the return of Lane Johnson.

If you've watched Wentz play, you've also picked up on how he has flummoxed teams with his scrambling. Wentz was an effective runner last season, but he didn't take advantage of his opportunities frequently enough. He scrambled 20 times for 140 yards, picking up nine first downs as a scrambler. Through five games in 2017, Wentz already has scrambled 14 times for 108 yards, racking up six first downs in the process. He also has converted three fourth downs with his feet, one more than he did in the 2016 season.

Wentz was shaky on longer throws over the middle in 2016, but he looks improved in every area in his second season. Bill Streicher/USA TODAY Sports

Can Wentz keep it up?

One element of Wentz's performance this season isn't sustainable. If you guessed that it was his third-down performance, you're familiar with outliers! As good as Wentz has been, it's incredibly unlikely he'll be able to keep that up over the remainder of the season, given how random third-down performance can be. Here's a look at Wentz and the nine other instances of a player posting a passer rating of 130 or more over 45-plus third-down attempts from Weeks 1 through 5 in the past, and how those same quarterbacks performed on third down the rest of the way:

Despite the fact that most of these players are going to be in the Hall of Fame someday, they each regressed drastically toward the mean over the final 12 weeks of the season. In fact, the only quarterback of the bunch to lead the league in third-down passer rating over the final 12 weeks of their respective seasons was Peyton Manning in 2006. If Wentz can post a passer rating over 100 on third downs the rest of the way, that would be a victory for the Eagles.

Wentz declining on third down would seem to set up a repeat of his swan dive toward Osweilerocrity (mediOscrity?) in October and November of 2017, but I think he should be able to sustain much of his broader level of performance. The third downs will decline, but I think he should be able to make up for it by producing more plays downfield, given how frequently guys are getting open. I find it difficult to believe Wentz is going to miss two or three downfield shots a week on a regular basis given his arm strength and general accuracy, and we saw an example of what he's capable of doing downfield against the Cardinals on Sunday.

General manager Howie Roseman also has provided Wentz with a better supporting cast than the Eagles had around him in 2016. The receivers are obviously better, and Wentz should grow only more comfortable with Smith and Alshon Jeffery as the season goes along. It hurts to go without Darren Sproles, who is basically a get-out-of-jail-free card for quarterbacks, but Wentz is also coaxing a career season out of Ertz, who is on pace for 102 catches and 1,238 yards. If those players stay healthy, Wentz should be in great shape.

His offensive line is also better by the presence of Lane Johnson, who was absent for 10 games last season thanks to a suspension. Wentz's splits with and without his star right tackle in 2016 were dramatic. With the former first-round pick on the field, Wentz posted a 67.2 QBR, throwing 10 touchdown passes against two picks. Once Johnson hit the bench, though, Wentz's QBR fell to 42.6, and he threw six touchdown passes against 12 interceptions.

The bad news for the Eagles is that Johnson won't be available Thursday night after suffering a concussion during Sunday's victory over the Cardinals. The Panthers might represent the toughest defense Wentz has faced this season, so it'll be interesting to see how he responds against Luke Kuechly & Co. on a short week.

The good news, of course, is that Wentz has arrived. In 2016, even including his three-week stretch of brilliance to begin the season, he was a below-average quarterback with above-average potential. Now, even if you regress his third-down performance toward the mean, we're seeing a quarterback who has improved across the board. He's quicker to make decisions and makes better choices in doing so.

With veterans such as Eli Manning and Ben Roethlisberger seemingly in decline, it's hardly out of the question to talk about Wentz as if he's a top-10 passer right now. In 2016, it was exciting to think about what Wentz might become. Now, it's exciting to see what Wentz has become.