The article referenced that he's averaging double figures in points and rebounds.
I thought this tweet from OU Basketball put that in a better perspective:
"Only 3 players (total) in American, ACC, Big 12, Big East, Big Ten, C-USA, Pac-12, SEC average a double-double. @Rspangler15 is 1 of them." https://twitter.com/ou_mbball/status/428381344100413440