Can first baseman stand in baseline when runner running to first?

Question
My daughter has been playing softball for years and started playing this spring in 10 and under fast pitch.  We had two games this weekend, both umpires told us something different on this occurance.  After the ball was hit by our team, the first baseman on the other team stood on first base facing the batter in the baseline.  Our girl didn't know what to do as she was blocking the base and of course didn't want to run right over her causing injury to both of them.  Ump in one game said for keep running to first and they would call it interference (by the first baseman) and we would be safe.   Next game ump said we had to just run on top of her and knock her down.  Isn't there a standard rule on this that players can not block the base by standing directly in the baseline?

Answer
Hi Margie,

Defensive player "obstruct" and offensive players "interfere" the terms are not interchangeable.

Obstruction is the act of a defensive player who does not have the ball or is not attempting to field a batted ball that impedes the progress of a runner legally running the bases.

In this case I would always have obstruction, you don't need to knock F3 down to get it.  I would counsel you not to as a safety issue for both players.

Right after the 1st occurrence I would go to the umpire and state your concerns over obstruction (memorize my 2nd sentence) (and the safety of the players). A good umpire is going to take care of it w/ the defensive player and/or the coach if they have to. If they want you to run down F3 please don't do that.  Tell them if it happens again and the b-r is called out you are going to protest the umpire understanding of the obstruction rule as a mis-interpretation of the playing rules.  You must protest immediately after the play.

Mark