Runner on base hit with batted ball

[drh898]

Ok, so if there was no intentional interference (in ump's thinking) by runner on base and the fielder may have had a chance to make a play the ball is dead, batter awarded 1st, runners advance 1 base. If the ball hits the runner (still no intent) fielder had no chance on play (in ump's thinking) ball is live? What if the ball hits the runner (no interference) but causes ball to change direction enabling fielder to make a play somewhere. Seems the offense is penalized for something that was not intentional interference or is it tough luck? Or maybe I'm missing something?

By the way, thank you for letting me bounce these things off you. Plays come up sometimes that seem in the grey area and I know you guys have the answers, so thanks.