I like to play a certain video game competitively and I've met a lot of friends by doing so. We usually have the same groups at local tournaments, so I've gotten to know these people enough to call them friends.
One in particular though--let's call him Bob--has severe anger issues. He knows he has a problem and is apparently trying to fix it, but it can be difficult to engage with him when little things can set him off.
For example, just last night we were over at someone's house playing for fun (so the stakes were low) and in the middle of a match Bob paused and quit the game, threw down his controller and cursed out one of the other players since that player kept using the same move and it kept working. He later said that the profanities and him quitting the game are ways for him to cope so he doesn't "have to turn around and punch" the other player.
When the player offered to stop using that character, Bob said that would make him even more upset. It seems he doesn't want to feel like people have to treat him differently, so he definitely doesn't want any special treatment.
Bob is actually a cool person when he's not upset and he's a lot of fun to play with. Not to mention he's an active member in the community for this game, so I'll definitely see him and play with him often. So simply avoiding him isn't an option. That being said...
When Bob starts to get visibly upset, how can I deescalate the situation and calm him down?