Runner on 3rd . I hit into a DP with one out . runner scores . Why dont I get awarded the Rbi ?
It's in the MLB official rules: 10.04(b)(1). I'm not sure what the official reasoning is, but one idea is that if the defense had time to turn a double play they probably could have put out the scoring runner instead.
Also, only a grounded into double play (GIDP) removes the rbi (in the reference Alex provided). A line drive into a double play, for example, could still score an rbi (though it would be awful tough!).
With the example you give in the original post, what was the situation exactly? If the 3rd out was on the batter/runner coming to 1st, then the run would not score anyway. I'm having trouble thinking of a play where you could ground into a double play and the run would score. I can think of things like flying to the outfield, and a runner being doubled off, the run could score, but that would not take away the rbit in that case.
I'm curious about the details now.
Sorry this is a little late.
First, the answer to the original question. It could be said that the defensive team conceded the run to turn the double play in which case it was not the batter that caused the run but the defense's choice. Think of how a Fielder's Choice does not give reward to the batter for getting on base or Defensive Indifference for a base advancement does not give a SB to the runner. Same concept.
The situations that this would be possible in are 0 outs and runners on first & third, or bases loaded.
Finally I would like to point out that Rule 10.04(b)(1) specifically states that an RBI cannot be awarded for a force double play or reverse force double play. All other double plays, grounders, flies or lines, do not fall under this exclusion.