He's actually better than half a rebound this year so far. By my math he's up almost 4 extra per 40 minutes. He's only at 20 minutes per game this year and at 5.4 rebounds in 7 games. Last year he was at 26 minutes, 4.4 rebounds in 35 games. Rebound rate seems to be up about 3% in total (all on the defensive end, meaning +6.5% on the defensive end).
Through the first seven last year he averaged 4.8 rebounds per game in 28 minutes per game. Now I'm not going to argue they are exactly the same quality of opponent, but I think they are similar through the first seven. Bryant, College of Charleston, Yale, Coppin State, WVU, Dayton and Texas last year. Maine, NHU, Furman, Sacred Heart, Michigan, Cuse and Gonzaga. The eighth game last year was Duke, this year Maryland. BTW, that Coppin State game boosted his average a ton and was a huge outlier on the year and in the first seven games. If we were talking just first six, his average would have been around 3.7. So far this year the spread has been much tighter at 4, 5x3, 6x2, 7.
I'm not saying he can't get better, but he seems to have improved a significant amount on the boards.
I'd also argue with better rebounders around him this year, his rebounding should be going down, not up. So maybe he's improved even more than the numbers show. Definitely something to track this year though.