[2] Allen led Clarkston to back-to-back Class 2A Washington state titles in 2015 and 2016 and a combined 51–2 record.

During Allen's senior year, he emerged as a leader on the team, playing both guard positions and small forward, and was called "a great ambassador for our program and this university" by new coach Zac Claus.

[6] As a senior, Allen averaged 21.6 points, 4.9 rebounds and 1.7 assists per game while shooting 44.9 percent from the field.

[5] On July 10, 2020, Allen signed his first professional contract with Starogard Gdański of the Polish Basketball League.

[4] His mother Sonya Samuels Allen is a Nez Perce tribal housing official, and she enrolled her son in the Confederated Tribes of the Umatilla Indian Reservation.

[1] Allen's younger brother Tru is the all-time leading scorer at Clarkston High School and committed to play for Northwest Nazarene.