errant throw to first baseman

Question
What is the ruling on a ball hit to shortstop that takes the first baseball up the line towards home - does the runner have to avoid contact?  Or if the first baseman moves to catch the ball and is now in the runner's box to try to catch the ball but does not yet have it, can he be call for obstruction?  Also, many times this is a play that causes the first baseman to leap to catch it unsuccessfully and enters the runner's box and the runner trys to avoid him but we still often a times have inadvertent contact how should this be ruled?

Answer
hi pete,

The defense must have control of the ball in order not to hinder the runner legally running the bases or they are guilty of obstruction.  About to receive the ball doesn't count.  

It's that simple, you can plug in any scenario you want to.. except if the ball, the defense, and the runner all arrive at the same place at the same time we have a "wreck" and that's a no call.

Mark