Panthers quarterback Cam Newton is coming off of the best season of his professional career. In 2015, Newton set career-best marks in just about every statistical category en route to his first MVP award, and his 15-1 Panthers made it to the Super Bowl. While you can say Newton had a wonderful defense at his back, few would look at Newton's supporting cast on paper and suggest that the former first overall pick had much help. His tackles were castoffs Michael Oher and Mike Remmers. His top wideout, Kelvin Benjamin, went down for the year before the season even started. Newton elevated the likes of Ted Ginn Jr. and Devin Funchess into a functional receiving corps.

Every other playoff team had more weapons than Carolina. With Newton, that didn't matter.

But 2015 is in the books. There's a chance we've already seen Newton's best season, which isn't remotely bad considering a player who peaks as an MVP is quite a player. During his career, though, Newton has continually taken on challenges and exceeded expectations. He led Auburn to the most unlikely of national titles, and after a poll of league executives suggested Blaine Gabbert was the best quarterback in the 2011 draft, Newton emerged as the best offensive player from his draft class. Cam led the Panthers to a division title in 2013, and in the famously topsy-turvy NFC South, Carolina managed to repeat during an up-and-down 2014 before a dominant 2015. His growth has also occurred during a time when the surrounding cast, from weapons to blocking, has remained a question mark.

So, now what?

Newton doesn't need to get better. He could take a step backward and still be an incredibly valuable quarterback. For a player as driven and impactful as he is, though, the possibility that he might still improve is exciting. As is the case with every player in football, there are places where Newton can grow and further develop. The former first overall pick only turned 27 in May, and there's still a reasonable chance Newton pushes forward. Let's figure out what an even better version of Newton might look like in 2016 and beyond.

Cam in 2015

Figuring out what an improved Newton might look like in 2016 starts by understanding what he did in 2015 and how likely some elements of that performance are to carry over. It's entirely possible that he could perform better on a play-by-play basis and produce worse numbers or win fewer games.

While Newton posted career bests in many categories, a look at those broader categories doesn't produce many dramatic outliers. His completion percentage (59.8 percent) and yards per attempt (7.8) were right in line or slightly ahead of his career averages. His interception rate dropped from a career mark of 2.8 percent to 2.0 percent, which is roughly a difference of about 3-4 interceptions per year in a typical Newton season. His passer rating leaped from a career mark of 85.4 to 99.4, and his 57.4 QBR through 2014 jumped to a mark of 66.0 last season.

The Panthers were dominant in the red zone in 2015, and Cam's high-flying act was part of the reason why. AP Photo/Chuck Burton

There's nothing outlandish in those numbers, which itself tells a story: Newton didn't have the statistical record of a typical MVP-caliber quarterback in the traditional way. I've noted in the past in looking at MVPs that they tend to be quarterbacks on highly successful teams (duh) and/or players who lead their position in terms of fantasy points scored. Newton didn't produce the sort of outlandish passing efficiency figures of a Tom Brady, but his incredible value as a runner led him to lead all NFL quarterbacks in fantasy points in a standard league.

Carolina's interior running is the heart of its offense, with an inventive scheme from offensive coordinator Mike Shula built to support the core of his team. The strength of the Panthers' offensive line is on the interior, with All-Pro center Ryan Kalil joined by emerging star right guard Trai Turner to carve out holes for Newton and lead running back Jonathan Stewart. This combination helped the Panthers become the second-best team in the league in what Football Outsiders describes as "power situations," where they needed two yards or less to go for a first down or a touchdown. Newton was 26-of-30 (86.7 percent) in picking up first downs with two yards or less to go last year against a league average of 66.9 percent. That's efficiency in an entirely different way.

Newton led the league in fantasy points by scoring a whole lot of touchdowns, and if there's an element of his performance which might not be sustainable, it starts there. Newton ran for 10 touchdowns last season after averaging eight over his previous four campaigns, which isn't crazy. As a passer, though, he threw for a whopping 35 scores after averaging 20 his previous four campaigns. 7.1 percent of his pass attempts resulted in touchdowns, which led the league and stood out notably compared to his previous average of 4.3 percent.

Those touchdowns were a product of remarkable -- and perhaps unsustainable -- success in the red zone. It makes sense that the Panthers would be good inside the opposition's 20-yard-line, but they were incredible in 2015. Carolina scored a league-high 5.54 points per red zone trip last season. With much of the same personnel, notably Newton at the helm for 30 of 32 games, they were 15th in the same category in 2013 and 23rd in 2014. As I wrote about earlier this summer, red zone performance is remarkably inconsistent from year-to-year. History suggests that Carolina -- and by proxy, Newton, who threw 24 touchdowns in the red zone without a pick -- will struggle to be as effective in the red zone in 2016.

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Saving their best performance for key moments was a huge reason the Panthers won 15 games and why Newton won MVP. It's not just that he was great; it's when he was great which stood out. If you could craft a case for when to weight a player's best moments during a season, you would build the resume Newton built in 2015. He got better as the year went along and played his best when the Panthers needed him most.

During the first nine weeks of the season, while the Panthers were starting 8-0, Newton posted a QBR of just 50.7, which was just behind Ryan Mallett for 24th in the league. Remember, QBR includes his performance as a runner, too; if you just want to consider traditional passing stats, Newton was 26th in the league in passer rating and 21st in adjusted yards per attempt. I don't believe Newton was truly a below-average starter -- the context of the offense built around him means something -- but I do think it's fair to say that he wasn't as dominant as his 8-0 record suggested.

Over the second half of the year, though, Newton's performance jumped. His QBR spiked to 79.5, which was the seventh-best mark in football and in line with the league's best passers. The typical NFL starter had three games with an QBR of 85 or greater last season; Newton had four of them in a five-week span between Week 11 and Week 15, cementing his hold as the top MVP candidate. While he fell off during Carolina's only loss of the season (to the Falcons in Week 16), Newton had already sealed up the hardware. His second-half performance might be a leap to a new level of play, but it is usually better to use all of a player's performance to project how he'll do in the future, as I talked about with Derek Carr last week.

Likewise, if you think a great quarterback needs to play his best in the fourth quarter, Newton was your man. Through three quarters last year, Newton's QBR was an above-average 63.1. In the fourth quarter and overtime, though, nobody beat Cam's QBR of 76.5. He posted a passer rating of 104.8 in the final stanza, and when the Panthers needed to get back into a game or close one out, their offense was devastating. Carolina had 17 meaningful possessions last year in the fourth quarter while the game was within seven points or less. Those drives produced more scores (nine) than punts (six), with the other two ending on a blocked field goal and Newton's fumble in the loss to the Falcons. Their five touchdowns included four Newton passes (all 15 yards or more) and a 13-yard Newton run.

Those sort of fourth-quarter leaps aren't really sustainable. Guys don't consistently elevate their game in the fourth quarter, which is logical if you think about it for a second: Why wouldn't you just play better all the time? Andrew Luck's career is a classic example. In 2013 and 2015, Luck's QBR jumped in the fourth quarter by 31.1 points and 42.1 points, respectively. In 2012, Luck's fourth-quarter QBR was identical to that of the previous three quarters, and in 2014, it declined by 1.2 points. Jay Cutler's QBR declined in the fourth quarter by 41.2 points in 2011; in 2012 and 2013, it improved by 38.0 points and 39.9 points. This is almost totally random.

The one other thing which might have aided Newton, of course, was more help from his receivers. My memory seems to suggest that Ginn dropped a 75-yard touchdown pass from Newton each and every week, but the data isn't quite as harsh. Ginn merely dropped seven passes last year, which was tied for fifth in the league, and as you might suspect, those drops were coming on what would have been big plays for the Carolina offense. Newton's overall drop rate was 3.8 percent, which was roughly league average. On throws of 20 yards or more in the air, though, Newton's drop rate spiked to 6.8 percent, which was the second-highest in the league behind the aforementioned Gabbert, who didn't throw deep anywhere near as frequently.

Cam in 2016

Start thinking about ways Newton might improve in 2016, and the presence of Benjamin is a jumping-off point. Benjamin had his own drop issues as a rookie in 2015, but he is unquestionably a more effective and impactful wideout than Ginn or second-year man Funchess -- though the second-year man out of Michigan is generating plenty of camp buzz -- and should represent the second-best receiver in Newton's arsenal behind star tight end Greg Olsen. The same caliber of pass from Newton is more likely to turn into a successful play with Benjamin on the other end.

Ted Ginn Jr. got open often in 2015, and this year the return of Kelvin Benjamin could mean even more space. Jeremy Brevard/USA TODAY Sports

There are elements of Newton's performance which statistically lag behind his peers, but I think they may be subject to the style of offense Carolina plays and the nature of Newton's style.

Start with his completion percentage. At 59.8 percent last year and 59.6 percent over his five-year career, it lags behind his peers. Newton's sack rate has also been higher than league average during each of his five pro seasons, although it was closest in 2015.

Those stats aren't strong enough to resist dramatically different contexts, and all you need to do is watch Newton to know that he's not playing in a typical offense. The Panthers ask him to chuck the ball downfield as much as anybody in football. Newton's average pass traveled 10.3 yards in the air last season, which was third in the league behind Carson Palmer and Tyrod Taylor. Since entering the league, the typical Newton pass has gone 9.4 yards, which is the longest average throw in football over that timeframe.

When you keep the context in mind, Newton's completion percentage is just fine. Football Outsiders has a statistic I helped create called plus-minus, which adjusts a quarterback's completion percentage for the distance and location of his throws. They've further adjusted the metric to account for the impact of dropped passes. When you account for the distance of his throws and the frequency with which his receivers dropped them, Newton's completion percentage was actually above-average and 13th in the NFL last year. Newton could still take another step forward from where he is now, of course, given that Palmer and Taylor each managed to complete nearly 64 percent of their passes while throwing similarly far downfield, but his completion percentage isn't subpar.

The natural place for Newton to improve, given Carolina's style of play, is on play-action. It makes sense that a team with a dominant running game like Carolina's would be great when Newton holds linebackers and safeties with play fakes, and while ESPN's play-action statistics don't count run-pass options (RPOs), Newton does create short, efficient completions for himself by reading the defense correctly when Shula calls them.

On traditional play-action passes, though, Newton wasn't very good last season. He finished 30th in the league in QBR on those throws with a 48.8 mark, including four of his 10 picks. Contrast that to Taylor and Palmer, his fellow downfield bombers, who finished first and second in QBR on play-action passes. This wasn't a small sample size fluke, either; 28.7 percent of Newton's dropbacks came with play-action, which was third in the league behind Colin Kaepernick and Teddy Bridgewater.

It's fair to say that Newton won't be that bad on play-action in 2016, given that he was better in years past. Newton's QBR on play-action throws was 17th in the league in 2013 and 13th in 2014. It's still a surprise, though, that he hasn't been downright dominant on those play-action attempts, especially given how effective the Carolina rushing attack has been over that timeframe. If there's an opportunity for Newton to grow and finish in the top-five somewhere new in 2016, it's here.

The most likely scenario for Newton in 2016, as is the case for the Panthers, is that they each decline a bit from their red-hot 2015 and still settle in the league's upper echelon. That would represent not just an incredibly valuable player but a staggering leap forward when you put Newton's history in context.

The same guy who was a controversial first overall selection and a quarterback expected to look up at Gabbert's NFL success is the clear face of the Carolina franchise (if not arguably the league as a whole) and a franchise quarterback. He doesn't need to get better, and he still could anyway. It's notoriously tough to repeat as NFL MVP. It's also notoriously tough to stop Cam Newton.