So what, if anything, got Mantha to play harder during his Wings tenure? Did he put forth more of an effort in bigger games / close games? Was he more energized with a particular type of linemate?
He is a player that thrives off of confidence and getting a fire lit under his ass. Not a fire that a coach can light though; there was discussion between Mantha and Blashill a few years ago that got them more aligned on his development. Essentially Mantha said if a coach just starts screaming at him, (big paraphrasing here, these are my words) he gets a little "deer in the headlights" tendency.
So when his game is on and he builds confidence he thinks he can do anything he wants, and he's one of the few people in the sport who can literally do anything he wants. His size/strength is enough to play in tight and getting to the net, his skating is strong enough to go around people or through people, his vision is high end, his shot is top 10 in the league when it's at its best.
When the confidence isn't high, he needs to find an element of aggression and assertiveness. If someone gets him with a high hit or a cross check/slash, he starts to get aggressive physically and through his effort level. I don't know how you control this aspect of his game. Blashill challenged him to be aggressive off the drop and get himself into games physically early, had him taking boxing lessons in the offseason to try to harness the aggression, and for a while it worked because he posted two strong season, including this past one where he flirted with a point per game rate and looked like he was ready to enter the upper echelon of wingers.
Since suffering the punctured lung on a Muzzin slewfoot during a fight, the aggression hasn't really been there, so it's really at this point just how do you build his confidence? I'd say game one for Washington is a good start. Playing with better talent and structure at every position, and having some other options to take heat off of him...I believe he will thrive. I've said that anything less than 30 goals next year is a disappointing season for Anthony, and I think he has a legit shot to flirt with 40 if everything clicks.