Runner Interference/Batter Out?
 

Reading OBR wording on runner interference.

R1. Less than 2 outs.

R1 interferes with F4 on a groundball.

One of the 7.09 (h?) says that if it deemed intentional the BR is also out.

If you have this type of situation what are you looking at in order to determine if it's intentional? Are you giving the benefit of the doubt to the defense?

If it was R2 instead of R1 would you ever call the BR out?

I'm looking for intent (and not just negligence or inability to get out of the way).

On your 2nd question, yes --- why not?

Did the defense have a (reasonably certain) double play? Did R1 kick at the ball, or just stop and let it hit him, or go out of his way to interfere, instead of trying (but failing) to avoid?

you can get it with R1 and R2 if R2 interferes, but it would be rare with R2 and no R1 -- the double play is rarely obvious here.

I would look for things like:
- R1 changing direction and going right at F4 instead of toward second base
- R1 stopping in front of F4 to shield his view of the ball, and then jumping out of the way at the last second
- R1 grabbing F4 or slapping at F4's glove as F4 tries to tag him
- R1 kicking the ball away

Essentially, as Mike said, I would make the call if R1 does something that doesn't appear to be a bonafide effort to achieve second base. That does not include stopping or heading back to first base.

IOW, "Hey, that ain't baseball!"