Some good info here. I'll just add one additional point.
Knowing when to nudge is the most important part. I see people nudging everything which can actually have a negative effect. You really need to project where the ball is going, what it will hit and what effect that will have. If that effect is a ball going towards the middle (SDTM) or the outlanes then you nudge. If that effect will move it to a flipper then you don't nudge. This is talk about the upper 2/3 of the PF.
Down by the outlanes, you are better off nudging upwards verses side to side. Your goal should be to get the ball up and out of that area and not to go into the inlane. If you can't nudge to get it up and over then as a last resort you nudge to get the opening of the inlane to where the ball will go. This is often times the opposite that your instinct will drive.
