Another fact about stats. If you are going to use them, you should know how they are derived.
Plus/minus, on its own, is a stat that holds less and less importance to people in, or who know, hockey.
Someone with a negative +/- was not necessarily on the ice for more goals for than against. Skaters receive a minus only when they are on the ice for an even strength goal against or if there is a shorthanded goal against.
Skaters do not receive a plus when they are on the ice for a powerplay goal.
Guys who rack up a large portion of their points on the powerplay will often have a lower then expected plus/minus. Yes, these guys are one demential, but no one wants a powerplay with no punch either.
It is also a stat that favours players on good teams. A mediocre player on a good team will often have a higher plus/minus than a good player on a bad team.
On its own the plus/minus number is often less then useless.