Not sure if I should continue to veer off topic, but I've always felt entering a game/event calm and collected was the better choice for most people. This includes other sports. Back in School and University I ran the 400m and 800m in track. There were always teamates running with me that wanted to listen music to get pumped up and excitable and "enter like a pit bull". Most (but not all) started hard and fizzled fast, usually slower in competition than their practice times. Hockey is more noticable than most other sports i think becuase of the breathold. I think the people it works for would be just as well off being mellow, and everyone else would benifit.

Pre-game/event routine is key to relaxing/performance in any sport as well. More noticable in an individual sport but I think just as helpful in team sports.

As far as staying intelligent. For a while I've classified some players as "Brain On" and some as "Brain Off". Most are somewhere in between. But is seems there are some people if they are not actively engaged and thinking about the game do dumb stuff, they need their "Brain On" to play well. Then there are others who when they start thinking their legs stop moving and they consistently throw pucks to the wrong people, they need their "Brain Off" to play.