Back bevel on planer knives
 

I had been watching "wood works" with David Marks on DIY when it was
still on He mentioned during a shop tour show he had a back bevel put
on his planer and joiner knives to reduce tear-out. I would like to
know for one does this help with tear-out in figured woods and what is
the angle I should try to put on the back bevel?

Thanks.