An NFL season reveals a lot. Teams and players undergo changes, evolve, figure out who they are and who they aren't. The stars of the prior year can fade into obscurity. Last year's draft busts can hit their stride.
But each year produces a fresh crop of "star" players -- players who capture the public's attention with their performances and the impact they have on their teams and the playoff races. 2016 was no exception, and a group of fresh young stars emerged from this season ready to help lead the league into the future.
Here's a look at some players who started the NFL season with question marks, but graduated into full-blown stardom.
Jay Ajayi, RB | Miami Dolphins
Who he was in August: One of a few committee running backs in Miami -- and not on real solid ground with the new coach, either. Adam Gase left Ajayi home when the team went to Seattle in Week 1, benching him for attitude-related reasons in an effort to get him on board with the team's plans for the position.
What he did: Handled all of that well enough to get another shot once Arian Foster got hurt. He ran for 204 yards against the Steelers in his first start, Week 6, then ran for 214 the following week. From Week 6 forward, Ajayi led the NFL with 1,155 rushing yards.
Who he is now: Certainly the starter for the Dolphins moving forward, and a back who has demonstrated enough that the team can run its offense through him.
Vic Beasley, OLB | Atlanta Falcons
Who he was in August: A first-round pick who'd shown some promise but not much consistency in a rookie season when he finished with just four sacks. The Falcons decided in the offseason to change his position in their defense to free him up to rush the passer more.
What he did: Led the NFL with 15.5 sacks in his second season and rejuvenated a Falcons pass rush that had been dormant for years. Atlanta finished 11-5, earned the No. 2 seed in the NFC playoffs and is headed to its first Super Bowl in nearly two decades.
Who he is now: Sacks are a money stat, and Beasley is the 17th player in NFL history to record at least 15.5 in a season at age 24 or younger. This sets him up for long-term stardom if he can continue to produce at the same level in the years to come.
Who he was in August: AWOL. Bosa and the Chargers carried a contract dispute all the way through training camp. He signed so late that he missed the first four games of his rookie season.
What he did: Debuted in Week 5 with a two-sack effort against Oakland and kept rolling from there. From the time of Bosa's debut, only the Falcons' Vic Beasley had more sacks than Bosa's 10.5. He was worth the wait.
Who he is now: An established, difference-making edge rusher on a team that believes it has enough pieces in place for a quick rebound.
Derek Carr, QB | Oakland Raiders
Who he was in August: A promising young quarterback whose completion percentage over his first two years was a substandard 59.6 and whose career touchdown-to-interception ratio was 2.08 to 1.
What he did: Led the Raiders to 12 wins, repeatedly delivering in the fourth quarter in one of the most exciting and heroic seasons any quarterback in the league has had. Carr had Oakland in position for a division title and a first-round bye before breaking his leg on Christmas Eve.
Who he is now: Following a 2016 season in which his completion percentage rose to 63.8 and his TD-to-INT ratio soared to 4.7, Carr looks like a bona fide franchise quarterback for the Raiders and a star in the league for years to come. Had he not suffered that injury when he did, it's possible Oakland could still be playing.
Jadeveon Clowney, DE/OLB | Houston Texans
Who he was in August: A bust, in the eyes of many. The No. 1 overall pick in the 2014 draft, Clowney had struggled with injuries and ineffectiveness in his first two seasons in the NFL. Houston needed him to step forward and be the bookend pass-rusher opposite J.J. Watt, and he had not.
What he did: Became the Texans' best player after Watt got hurt. Clowney's six sacks don't tell the whole story of his year. He emerged as an unstoppable force against the run and the key cog in a defense that finished No. 1 in the league, even without Watt.
Who he is now: A star who's living up to his No. 1 overall pick pedigree. If he can shake off the injury issues that seem to dog him, his star will only rise following the return of Watt.
Who he was in August: A disappointing second-round pick who was forced to play out of position as a rookie due to the Giants' lack of other options at the safety position in 2015. Collins admitted then, and would admit now, that his first season overwhelmed him and was not up to his standards.
What he did: Moved full-time to strong safety and blossomed, making 100 tackles to go with 13 pass breakups and five interceptions. Collins became the headline playmaker on a defense that helped the Giants rebound from two straight 6-10 seasons to go 11-5.
Who he is now: A star at a position that seemed to be going out of style not that long ago. Anyone who watches the Giants can spot Collins' value as a hard-hitting, fly-around disruptor. But once you start making interceptions and running them back for touchdowns, even people who don't pay close attention know who you are.
Kirk Cousins, QB | Washington
Who he was in August: Still a question mark, as far as his team and most fans were concerned. After leading Washington to a division title in 2015, Cousins was playing on the franchise tag in 2016 because his team wanted to see him build on his first taste of NFL success.
What he did: Finished third in the league with 4,917 passing yards and sixth with a 71.7 Total QBR. Washington's season ended in disappointment, as home losses down the stretch to Carolina and the Giants cost it a repeat playoff appearance. But if the team was looking for Cousins to perform at an elite level before committing to him, he did.
Who he is now: Likely Washington's quarterback of the future, and one of the more intriguing 2017 contract stories. Franchising him again would be costly to the team and likely aggravating to the player. A new contract would have to be at the top of the quarterback market, since he'd blow that out of the water if the team let him leave as a free agent.
Who he was in August: A superstar college running back, but one whose status as the No. 4 overall pick in the draft was questioned by some due to the Cowboys' apparent needs on defense.
What he did: Led the NFL with 1,631 rushing yards -- 313 more than second-place Jordan Howard of the Bears. Behind Dallas' all-world offensive line, Elliott was everything the Cowboys drafted him to be, allowing them to ride their ball-control offense to the best record in the NFC.
Who he is now: One of the best backs in the NFL and, along with Dak Prescott, a reason for the Cowboys to believe they can sustain their 2016 success well into the future.
Who he was in August: A 23-year-old former first-rounder whose jump from Year 1 to Year 2 wasn't as dramatic as many expected it to be. After catching 12 touchdowns as a rookie in 2014, Evans caught only three in Jameis Winston's rookie season of 2015. Some wondered if they'd develop chemistry together.
What he did: Caught a career-high 96 passes for a career-high 1,321 yards and, just like his rookie season, 12 touchdowns.
Who he is now: A clear No. 1 wide receiver for Winston and one of the best at the position in the entire league. He put up Odell Beckham numbers this season, and Evans' considerable size makes him almost impossible to defend in the red zone.
Who he was in August: A 2015 third-round pick who finished that season exceptionally strong, and whose offseason had his team dreaming big dreams about what he might accomplish in 2016.
What he did: Rushed for 1,239 yards and 16 touchdowns. Caught 80 passes for 879 yards and four more touchdowns. Tied Barry Sanders' NFL record with 100 or more yards from scrimmage in 15 straight games, which could have become 16 had he not been injured in the season finale.
Who he is now: One of the top all-around offensive weapons in the entire league -- a player through whom the Cardinals' offense can run, regardless of game plan or matchup. Had Arizona finished over .500 and been in contention this season, Johnson's numbers would've made him a leading MVP candidate, even in this season's strong field.
Who he was in August: A still-promising former third-round pick headed into his fourth season and, apparently, having trouble finding a girl.
What he did: Caught 85 passes for 1,125 yards -- his first career 1,000-yard season -- and became a focal point of the Kansas City offense as the Chiefs won the AFC West. He also had his own reality show, "Catching Kelce," designed to find him a girlfriend.
Who he is now: A star player who is recognizable to non-football fans too, by virtue of his crossover status. More great football to come for Kelce, as long as he keeps his temper in check. And he seems as if he'll be set up just fine post-career, too.
Who he was in August: A well-regarded former Heisman Trophy winner coming off a promising rookie year that was cut short by injury. The consensus was that his team was a ways away, and that he needed a strong group around him in order to blossom.
What he did: With the help of a good young offensive line, Mariota threw for 3,426 yards, 26 touchdowns and nine interceptions to continue his progress at the NFL level and help the Titans to a surprising 9-7 record.
Who he is now: A sky's-the-limit, 23-year-old quarterback who has impressed with his ability to lead and make decisions in the heat of the game. Possibly just a true No. 1 receiver away from taking a Derek Carr-style third-year leap.
Who he was in August: The 2015 Defensive Rookie of the Year, so it's not as if he came out of nowhere to make this list.
What he did: Intercepted six more passes to go with the eight he grabbed as a rookie. But more than that, the underlying numbers prove Peters was a much better coverage corner in 2016 than he was in 2015. He was not beaten as badly or regularly as he was in his rookie season.
Who he is now: His reputation as a ball hawk is well deserved and not going anywhere, and that's what will make him a star. But Peters established himself in 2016 as a reliable corner who can be a building block for a very good Kansas City defense.
Dak Prescott, QB | Dallas Cowboys
Who he was in August: A fourth-round pick and, at best, the Cowboys' third choice of draft quarterbacks behind Paxton Lynch and Connor Cook who was pressed into service as the fill-in starter while Tony Romo was injured.
Who he is now: The Cowboys' starting quarterback, both of the present and the future. The story is no longer about whether Prescott can hold off Romo. It's about what to do with Romo now that he has been replaced.
Who he was in August: Another well-regarded former Heisman Trophy winner coming off a promising rookie season, but with questions about his protection and penchant for throwing interceptions.
What he did: Played all 16 games for the second year in a row, got his completion percentage over 60 and threw 28 touchdowns to go with, yes, those 18 interceptions. Led the Bucs to a 9-7 record and the fringes of playoff contention.
Who he is now: While questions linger about those interceptions, Winston did a lot of what he did in college -- found ways to win. It's clear he's tough and durable and knows how to lead his team. He and Mariota will forever be compared with each other, and if they continue to progress the way they did in 2016, it'll be a fun debate for years to come.