Rules on Balking

Question
Today I saw an umpire do something I've never seen before and it confused me.  There was a runner on first and third.  The pitcher balked and the ump advanced the runner on first instead of having the batter take his base (which still would have advanced the runner).  I have never seen a runner advanced instead of the batter before.  Is this a legal move, or just one rarely used?  And what is the logic behind that kind of a decision?

Answer
Candy,

The penalty against a pitcher for balking is to have the baserunners advance.  If there are no base runners, then the pitch is called a ball.  The only way a hitter would advance to first is if they had three balls on them and there were no runners on base.

Hopefully the umpire sent both the runner on third and the runner on first ahead one base in the situation above.  That balk should have caused one run to score.

Hope this helps!

Brian