I don’t follow hockey, so it was news to me that the Finns are disproportionately represented among elite goaltenders. There is a fair amount of the typical sports fluff in here, but also a lot of interesting bits (at least to a hockey neophyte!) on craft, competing schools of thought, and history:

http://www.theatlantic.com/features/archive/2014/03/the-puck-stops-here/357579/

If I were to sum up the technical content in one short quote, this would be it:

The butterfly is a kind of algorithm that maximizes your total physical size so you can take up as much of the net as possible, to stop second and third chances and allow your defensemen to clear the puck away. A hallmark of Finnish goaltending, by contrast, is that there is no second chance.