I made a mistake. You do get a plus or minus for a shorthanded goal. I was going by what I have been told over and over by the local announcers. I looked around a bit to verify that the information was correct and found this link, which states:
When an even-strength or shorthanded goal is scored, every player on the ice for the team scoring the goal is credited with a plus. Every player on the ice for the team scored against gets a minus. A player's overall total is calculated by subtracting the minuses from the pluses. A high plus total is taken to suggest that a guy is a good defensive player.
I verified it on another site, so I apologize for the misinformation.
What makes the gaudy plus/minus ratings of Gretzky and Orr even more absurd is the fact that they were both on the ice for somewhere around half of any given game (well, Gretzky not quite half and Orr just over half).
A plus/minus of +20 or better is excellent--only 30 or so guys in the league this year did better. Forsberg and Hedjuk lead the league with +50, which I'd consider pretty ridiculous; but numbers like +98 and +124 are not of this world.
http://sports.yahoo.com/nhl/blog/puck_daddy/post/-lsquo-PC-Load-Letter-rsquo-Tallon-rsquo-s-sna?urn=nhl,174746 The gist of the story is the GM mailed out qualifying offers to several of their restricted free agents.