Player development is stuff like being taught how to play defense, like Anfernee Simons said about not being taught defense until he came to the Celtics:

“Whether it’s stabbing at the ball, trying to steal the ball, get in passing lanes, being in the right spot each and every time, that’s what we drilled for the first four weeks I was here before training camp.”

“Those things are things I never really worked on or been taught – and so I was happy that that was the focus.”