I mean, a lot of defense is mindfulness and effort/hustle. If a puck carrier is trying to skate around a player, a good defensive player will use his feet to close the distance and try and smother the attacker and generally just jam him up. A lazy defensive player will glide and do a half-assed sweep with their stick and just let the guy skate right by. There’s not some sophisticated thought process going on with the former, it’s just a question of effort. Take a floaty player who’s brain shuts off on the defensive side and have him be engaged and putting in the effort and I think you see some results.
I would never expect Sprong to be a great defender. Someone like Datsyuk who is always analyzing and anticipating and acting rather than reacting. But with proper effort and dedication to improvement, I don’t see why he couldn’t be a competent defender. Hopefully he is sincere in wanting to round himself out as a player, Sprong with even average defense is a really valuable piece.