NBA


James was selected by the Cleveland Cavaliers as the first overall pick of the 2003 NBA draft. In his first regular season game, he scored 25 points against the Sacramento Kings, setting an NBA record for most points scored by a prep-to-pro player in his debut performance. At the conclusion of the season, he was named the NBA Rookie of the Year, finishing with averages of 20.9 points, 5.5 rebounds, and 5.9 assists per game. He became the first Cavalier to receive the honor and just the third player in NBA history to average at least 20 points, 5 rebounds, and 5 assists per game in his rookie year. The Cavaliers finished the season 35-47, failing to make the playoffs despite an 18-game improvement over the previous year.

In 2006–07, James's averages declined to 27.3 points, 6.7 rebounds, 6 assists, and 1.6 steals per game. Some analysts attributed the fall to a regression in his passing skills and shot selection, stemming from a lack of effort and focus. The Cavaliers finished the season with 50 wins for the second consecutive year and entered the playoffs as the East's second seed. In Game 5 of the Conference Finals, James notched 48 points with 9 rebounds and 7 assists, scoring 29 of Cleveland's last 30 points, including the game-winning lay-up with two seconds left, against the Pistons. After the game, play-by-play announcer Marv Albert called the performance "one of the greatest moments in postseason history" and color commentator Steve Kerr described it as "Jordan-esque". In 2012, ESPN ranked the performance the fourth greatest in modern NBA playoff history. The Cavaliers went on to win Game 6 and claim their first-ever Eastern Conference championship. They advanced to the NBA Finals, where they were swept by the San Antonio Spurs. For the Finals, James averaged 22 points, 7 rebounds, and 6.8 assists per game.

At the conclusion of the 2008–09 season, James finished second in NBA Defensive Player of the Year voting and made his first NBA All-Defensive Team, posting 23 chase-down blocks and a career-high 93 total blocks. He also became only the fourth postmerger player to lead his team in points, rebounds, assists, steals, and blocks in a single season. Behind his play, Cleveland went a franchise record 66-16 and fell one game short of matching the best home record in league history. With averages of 28.4 points, 7.6 rebounds, 7.2 assists, 1.7 steals, and 1.2 blocks per game, he became the first Cavalier to win the MVP Award.