Balk Not stepping off the rubber & throwing to 1st

Question
Rule 8.05 says it is a balk to not step off and feint a throw to the base, it does not say that you have to step off to throw to first base. How come most Umpires will call a balk if the pitcher does not step off before throwing to first?

I have umpired off and on for the last 30 years, always as a volunteer, I coach two baseball teams, one little league (no balking) and one tournament team.  I have always taught my kids by the rule, if they are going to throw to the bag, they do not need to step off the rubber.  I have had numerous Umpires tell me this is a balk if you don't step off the bag and throw to first.  When I have asked them to show me the rule they can't and tell me it is judgment call.

Answer
Michael,

A left handed pitcher can step toward 1st base and make the throw without stepping off of the rubber.  A right hander can't make the step because they have to turn around.  So a right hander has to step off of the rubber.

That's probably the difference you have seen.

Hope this helps!

Brian