MLB Rules: Can a Batter Run on a Dropped Third Strike with a Runner on First?

Question
if first base is occupied by a runner, less than 2 outs, can the batter run to first base, after a third strike is missed by the catcher?

Answer
Dan,

If there are less then two outs, the batter cannot run to first base on a dropped third strike if the base is occupied.

If there are two outs, or first base is open, then the batter can run down to first and is only out if they are put out.

Hope this helps!

Brian