Kirsken,

Here is a video you need to watch,

Tracking before and after with Mike Lapinski made by Stone Wolf Productions.
1-800-237-0060

Not only does it show a good number of " jumping the string" it also shows where the arrow would have impacted if the deer didnt move and/or outlines of the vitals.
Not to mention many poor penetration shots by some folks, kinda makes me wonder.....good vid bar none for what you are looking for.