by the way, a little off topic but you mentioned singles...I heard Jim Stevens comment once on a video that no one whos primary position is goalie has won open singles at Worlds (Tornado of course)...it is always a forward with a strong goalie game not the other way around
I would be willing to bet that in any Major (not just Worlds) stretching back as far as people want to go, you will be hard pressed to find the exception to this rule...I am sure there is one or two but I can't remember seeing it in the stats I have seen but I am certain it must have happened once or twice
however, bottom line is, it is very rare...
probably happens more often in lower ranks because there are so many random variables which is one of the things that makes lower ranked play so difficult to win consistantly...those that have won consistantly at the lower level have games developed WAY beyond everyone else and usually sky rocket into the PM ranks after a 1 1/2 to 2 years of dominance (some examples of people since I have been back playing are Ryan Moore, Blake Robertson, Kane Gabriel, Dainel Colter, Chris Harrington, Chris Hagerman, and Ron Olson)