A couple notes from a game I watched;
- Tall frame, about 6'2" I presume possibly bigger (eliteprospects page has to be off)
- Lacks physical strength and explosiveness, he likely just hit a growth spurt and is still gaining weight
- Really strong playmaker
- Terrific vision
- Great at receiving passes and using his lengthiness to open lanes that might not be there for smaller players
- Great at joining the rush at appropriate times, many defenseman don't seize the opportunities like he does
- Can be weak defensively in the corners, but makes great use of his body to box out the opposition
- Gets caught flat footed through the neutral zone
- Gains a lot of speed using his hips (great crossovers)
- Struggles with quickness/explosive steps
He has an entire summer to improve on some of this stuff and most players his age struggle. Even Schaefer wasn't that dominant the year prior