Rookie seasons are an athlete's introduction to the world of professional sports. When LeBron James was a rookie in 2003, it was obvious from his first game that the dynamic of the league had shifted for the foreseeable future (we're going on 20 years of LeBron as the face of the NBA now, so in hindsight the unforeseeable future also changed drastically). Intros can also be misleading. This rule stretches well beyond sports. It can be true for a TV show that has an awesome first episode or season and never reaches that hype again. It can be true for music - the first song on Logic's Under Pressure album actually kind of slapped but then you realize listening to the rest of the album that it's still Logic. It can especially be true for rookie seasons. In recent years, we have seen many athletes have strong rookie seasons only to fail to improve or reach those heights again.
Michael Carter-Williams won the 2014 Rookie of the Year award after averaging 16.7 points, 6.2 rebounds and 6.3 assists per game for the 76ers. As the 11th overall pick in the 2013 NBA Draft MCW was supposed to have a meaningful impact as a neophyte, but his strong rookie campaign reset the expectations on the Syracuse alum. Carter-Williams was named the Eastern Conference Player of the Week in his first week in the NBA, becoming the first rookie to do so since Shaq in 1992. MCW became the first 76ers rookie to record two triple-doubles in the same season, and became the first rookie drafted 10th or later to win the RoY award since Mark Jackson in 1987. However, Carter-Williams took a step back after his promising rookie season. Removing his stats from his RoY campaign, Carter-Williams' career averages are 8.4 points, 3.6 rebounds, and 3.8 assists per game. MCW has played for six NBA franchises in 10 years, but is still active today as a member of the Orlando Magic.
Marcus Mariota was fresh off a Heisman Trophy and (inaugural) CFP National Championship Game appearance when the Tennessee Titans made him the #2 overall pick in the 2015 NFL Draft. Mariota's career started off about as hot as it possibly could have: facing #1 pick Jameis Winston and the Tampa Bay Buccaneers in Week 1, Mariota threw 4 touchdowns against only 2 incompletions in a 42-14 win. Mariota became the first player to post a perfect passer rating in his first start en route to being recognized as the AFC Offensive Player of the Week. Mariota led the Titans to the playoffs in 2017 but never threw for more than 3,500 yards or 26 touchdowns as a starter. Despite posting a historic statline in his first game, Mariota never developed into the star that Tennessee hoped he would when they drafted him out of Oregon.
Tangent: Almost every trade deadline in the NBA, one of the guys that gets moved is a former lottery pick of anomaly-ROY who from that trade will go on to have a largely uneventful career and do what most NBA players that have uneventful careers do - make $100+ million. Anyway, we will call this phenomenon the Tyreke Evans affect.
Tyreke Evans was the 4th overall pick in the 2009 NBA draft out of the University of Memphis. Evans won Rookie of the Year and was only the fourth rookie to ever average 20-5-5 (after Oscar, MJ and LeBron). Evans was never able to replicate his rookie success after transitioning to more of an off-the-ball role after the Kings acquired Isiah Thomas. He was traded to New Orleans in 2013 and back to Sacramento in 2017 before signing with Memphis and then Indiana. His scoring average declined for four straight years after his rookie season and he never cracked the 20ppg mark again.
Evans was banned for three years for violating the NBA's Anti-Drug program in May 2019. He was reinstated in February 2022. He signed with the G-League's Wisconsin Herd on March 16 2023 and was released a week later.
Steve Mason made his NHL debut for the Columbus Blue Jackets in the 2008-09 NHL season. He won Rookie of the Year after posting 33 wins to go with a 2.2.29 GAA and a .916 SV%. Mason was never able to replicate the success that he had as a rookie and only won more than 20 games once more as a member of the Blue Jackets.
After starting only seven games during the lockout-shortened 2012-13 season, Mason was traded to the Philadelphia Flyers for Michael Leighton and a 3rd round draft pick. Mason played for 5 seasons in Philly primarily as the Flyers starting goalie but never reached his pre-Philly levels. He was out of the NHL by 2017-18.