Lots of really big men have trouble rebounding their first couple of years in the league Out of college, especially when they come from a smaller school like Queta did. They’re so used to just being so much bigger than anyone else that they never learn how to box out/properly time rebounds. Mobley’s had a similar issue for Cleveland in summer league. Sengun hasn’t but the Turkish league is much more thorough in big fundamentals than most college programs aside from Kentucky (Calipari for all his faults is really good at developing interior skills for big men that lots of other college coaches have sort of forgotten about)