Tinkle was born in Missoula, Montana to Lisa and Wayne Tinkle on June 3, 1996. He played high school basketball at Hellgate High School for coach Jeff Hays, lettering all four years. He averaged over 20 points and 7 rebounds his sophomore, junior, and senior years, finishing his high school career with a school-record of 1,580 points. He led the team to the 2013 Class AA state championship as a sophomore, the state title game as a junior, and third place as a senior. He was named First Team All-State and All-Western Conference all four years and was named Gatorade Montana Boys' Basketball Player of the Year in 2014 and 2015. He also played AAU basketball with Anthony Davis Idaho Select and Earl Watson Elite. Tinkle attended the Nike EYBL, NBATop 100 Camp, Kevin Durant Skills Academy and the LeBron James Skills Academy. He was ranked 91st overall on the ESPN 100, 82nd overall by 247 Sports, 88th by Scout.com and 93rd on the Rivals 150 list. ESPN listed Tinkle as a four-star recruit.
College career
As a freshman, Tinkle played in 27 games, starting 11, before missing the final five games with a right foot injury. He averaged 13.1 points, 5.4 rebounds, 1.1 assists, 1.2 steals and 0.5 blocked shots in 27.7 minutes per game, earning a Pac-12 All-Freshman Honorable Mention. As a sophomore, Tinkle started six games, averaging 20.2 points before being sidelined for the rest of the season with a broken right wrist. Tinkle met the requirements for a medical redshirt, and regained his year of eligibility. Tinkle averaged 17.6 points and 7.2 rebounds per game as a redshirt sophomore as Oregon State finished 16–16. As a redshirt junior, Tinkle averaged 20.8 points, 8.1 rebounds and 3.8 assists per game, helping the Beavers finish 18–13 overall and 10–8 in the Pac-12 — their best in-league record since 1990. He considered jumping to the pros after the season, but came back to Oregon State for his final year. Tinkle scored his 2,000th career point on January 18, 2020, in a loss to Washington State, becoming the 16th Pac-12 player in history to surpass the milestone. Tinkle shot 9 for 20 from the field and scored 22 points as well as collecting eight rebounds as the Beavers fell to the Cougars 89–76. At the conclusion of the regular season, Tinkle was named the first-team All-Pac-12 for the third consecutive season.
Career statistics
College
Personal life
Tinkle's father, Wayne, is the current Men's Basketball Coach at Oregon State. His mother Lisa formerly played basketball at the University of Montana. He has two sisters, Joslyn, who plays for the Sydney Uni Flames professional women's basketball team, and Elle, formerly a member of the Gonzaga Bulldogs women's basketball team. He chose to go to Oregon State to play basketball under his dad. His favorite athlete is Dwyane Wade. Tinkle graduated high school with a 3.9 GPA and is majoring in University Exploratory Studies.
