Interference call during a game and result

Question
I am the coach of a 12U club fastpitch team.  This past Saturday, while on defense and a runner on first base with no outs, the batter hit a hard grounder to our second baseman as the runner on first attempted to go behind her.  The runner looked as if she brushed the back of our second baseman as she turned slightly to try to tag her (this all happened as our second baseman was in the act of fielding and quickly turned to attempt the tag.)  From my angle, I couldn't see if she made the tag, but the runner clearly made contact with our second baseman as she attempted to pass her. Our second baseman with possession of the ball, then fired to first and got the batter out by at least 5 feet.  The field ump raised his hand and declared interference on the runner going to second and called her out but said the batter was safe.  It was explained to me by the umpire that upon interference, the runner is out but it becomes a dead ball and the batter would then be safe at first.  I argued that if that is the case, then why wouldn't we as a team try to interfere with the second baseman every time to break up a double play so the runner at first would be safe?  He didn't have an answer to that. My question is, why was the runner safe at first and was this the right call?  Thanks

Answer
Hi Mike,

IF we have interference here (and I'm not sure we do but I didn't see the play.) the ball is dead, the runner is out and the b-r is awarded 1st base.  Since the ball is immediately dead there can be no play at 1st and in normal interference calls the b-r is awarded 1st base.

"I argued that if that is the case, then why wouldn't we as a team try to interfere with the second baseman every time to break up a double play so the runner at first would be safe?" I wouldn't teach or do that, it will bite you and may cause ejections depending on what the runner does...... if the umpire judges that the interference was an attempt to prevent a double play and occurs before the runner is put out we can call the b-r out also. I really don't see that from your OP but again I didn't see the play.

If the interference occurs after the runner is put out, the runner closest to home is called out.  That could be the b-r or someone else.

I hope this helps

Mark