Full Deck Favorability

I'm currently reading Blackjack Attack and I'm kinda stuck on the term "full deck favorability" (3rd edition p64). The explanation in the book seems straight forward enough, but for some reason I'm not getting it. Any help would be appreciated.

Thanks,

Homeschool

I don't have the book with me but I believe there is a better explanation about it in the chapter about the effects of removal, with a lot of examples.