Well I know he watches all the games twice, in his office, at home or in hotels. This is something he's mentioned before.
He has to pause them frequently, write notes, take time stamps and formulate ideas for the next practice, video session or coaches meeting. He has to prepare the material. That's time consuming.
Or in the case of packed stretches like we've had recently, it's something he does in the morning after travel, before the 2nd of a B2B. This entails a lot of work on off-days or time for everyone else.
He needs to focus on all aspects of the game, whereas assistants like Reirden and Vellucci only needs to watch the special teams and the contingent of players they're overseeing.
Sullivan needs to meet with Hextall before/after all practices and grade players, and discuss solutions moving forward. So there's this pressure of being immediately accountable for recent results and players under your command, with your boss staring at you from across the table. It's not easy to deal with when things are going poorly. We've seen this done with Bylsma and Shero in the behind the scenes documentaries.
The human aspect is one of the hardest things. Lineup decisions. Sullivan is the one that takes all the negative emotions from unsatisfied players, like with demoting someone to Wilkes. He needs to broach sensitive topics, and play sports psychologist/father too. Fortunately we have a fairly mature, professional team that don't give him too much grief. This Kap situation recently must have been tough though, as was the nightmare that is training camp cuts. You gotta inform players that played well to take a hike until there's injuries, and they're not gonna be happy about it. Like I'm sure a veteran like Caggiula who did great in camp was in the dumps. Or what about how Smith felt after killing it?
Managing minutes is a pain in the ass every game that Reirden and Vellucci don't really have to do. He needs to be prepared for every shift change. A lot of pressure there to keep things balanced.
He's in charge of practice planning, and has to keep things fresh and fun to keep the players invested. It's often a glum atmosphere after losses, which makes his job harder. He needs to keep a lot of his anger in check too, when frustrated with certain players. His capacity for patience is actually pretty commendable. He rarely loses it.
Media obligations is a bitch. He needs to explain his decisions before and after every game and practice. A lot of media people take too many liberties with their questions and arrogance, and they're asked at points when the coach is vulnerable. Would you wanna deal with Rossi, Kovacevic and Yohe, telling you what's f***ed up with your team?
Sullivan has actually handled them admirably, to the point where they all respect him.
How many interviews do Reirden and Vellucci take annually?
What else? There's the calls he takes from JD Forrest, the events he needs to attend, the road trip excursions he needs to plan, the long term workload plan for goalies...
I'm sure there's many things I haven't mentioned. The players were asked this year if they'd rather be a HC or GM after they retire. 100% of them said GM.