Brain cramp - ball hits b-r
 

Sorry to bother you all, I know this is simple stuff but I've got a brain cramp - but here's my question: batter hits pitch, becomes batter-runner as she leaves batters box. Ball hits in front of plate but has wicked backspin and (IMO) b-r cannot avoid contacting ball as she heads to 1B...ball deflects off her left hip but stays in the playing field. Is b-r automatically out? Does blue have to determine intent? Can runners advance or immediate dead ball? Thanks so much.

Dead Ball. Interference. BR out. Other runners return to last base touched. Intent is not required.

The question I have is where was the BR feet at the time of contact with the ball. It would seem likely that the BR could still have been in the batters box when contact with the ball was made.

If still in the batters box, dead ball no out.

If outside the batters box, dead ball, interference, BR out.

as she leaves batters box.

I think this gives us a hint. ;) What the OP doesn't state is whether the ball was over fair or foul territory when contacting the BR.

When in doubt, foul it out.