Division championship game. Chino Hills fell in overtime to Centennial High School at the Southern California Regional Division I final. As a sophomore, Ball was teammates with his brother, Lonzo, and his cousin, Andre Ball. He suffered a foot injury before the season and missed a tournament at Fairfax High School in June 2014. On September 14, he scored 35 points with seven three-point field goals to win the Ron Massey Memorial Fall Hoops Classic. In December 2014, Ball scored 53 points in a 111–80 win over Dorsey High School. At the end of the season, Ball was sidelined for four games with an ankle sprain but returned for the playoffs. His team lost at the CIF State Division I championship game. After the season, on April 21, he verbally committed to play college basketball for UCLA. Junior season In his junior season, Ball played with both of his brothers, Lonzo and LaMelo. In December 2015, Ball scored 32 points to upset top-ranked Montverde Academy in the City of Palms Classic quarterfinals. He scored 40 points in a semifinal win over High Point Christian Academy and won the tournament. Against Jonesboro High School at the MaxPreps Holiday Classic, Ball scored 41 points. On February 11, he led all scorers with 32 points against Etiwanda High School, as Chino Hills finished the regular season with a 27–0 record. On March 5, 2016, he scored 31 points to win the CIF Southern Section Open Division title over Sierra Canyon School. On March 26, he had 18 points to win the Open Division title over De La Salle High School. As a junior, Ball averaged 27.4 points per game, which led his team. His team finished 35–0 and was named mythical national champion by MaxPreps, who also labeled their title run "perhaps the best brother act in high school basketball history." Senior season On November 29, Ball scored 56 points in a 121–89 win over Lutheran High School of Orange County. In his following game, which was played on the next day, Ball scored a career-high 72 points with 13 three-pointers in a 128–108 victory over Rancho Christian School, the tenth-most points scored in a single game in California high school history. On December 26, he scored 65 points in a Rancho Mirage Holiday Invitational win over Foothill High School. On January 20, 2017, Ball scored 60 points in a 136–93 win over