Avoiding an obstructing defender

[JefferMC]

I know that in most (if not all) rule sets, it is clearly spelled out in the rules that the onus is on the offense to avoid contact when the defender has the ball. I know that, in general, the onus is on the defense to stay out of the way when they don't have the ball, and the penalty for not doing so is supposed to be an obstruction call. But if they don't stay out of the way, by rule what is the runner supposed to do? Especially in case of something like a run down where the ball goes back and forth and the defenders sometimes just don't get out of the way after throwing the ball, there's not a lot of opportunity for "going around" and the runner may be too far from the base to slide.

I was having a discussion with someone who says that he teaches his players to "make contact, not hard contact but contact, and then hope the ump calls the girls for obstruction." To me, this is counter to the whole reason behind the obstruction rule.

What do you say?