The player has slow feet. He is slow. It is a fact. Defensively he might have gotten better. When you were already a terrible defensive player, please define better?
wait. are you describing olly or bird?
Lol. I had the same thought. And like Bird, he excels in team defense.
The comment about Kelly's alleged slowness is particularly ironic in light of Coach Nick's video, linked above, which advocates for Kelly in the starting lineup - precisely
because he's quicker than Horford to close out on the perimeter.
Olynyk has defensive limitations - guarding a quicker guy out on the floor in an iso is a particular problem, and his post defense is mediocre despite some good moments. Perhaps some of those things are what brother Flybono is seeing. But his pnr defense is excellent, he anticipates, gets deflections, has good habits and feel for spacing, doesn't ball-watch. As mentioned above, he's one of the league leaders in drawing charges and leads the team in defensive rebound% - evidence, if any were needed, that he gets physical.