One thing you see from Marner is that when he gets the puck, he likes to have it in front of him. But when you're playing against better teams and more structured defenses, it exposes the puck. The fact he has it way in front of him he has to bring the puck back from out front to his right foot or hip pocket. It's a split second but the time it takes to bring it back, allows the Boston defense to pressure him. Marner has to sacrifice himself to advance the puck to a teammate but it creates a problem. He has difficulty creating space because he has to worry about a defenseman going stick on puck, forcing him to lay the puck in and forecheck. Marner works really hard but he's not the best forechecker.