I have always interpreted it is a "quarterback" sack. Sounds like you want to bet an over or under figure in sacks for the game and want to clarify whether a kicker, holder etc. being tackled adds to this total. Now, if the holder(sometimes a QB) drops back , sets up or is rushed to throw a pass.......is something that you should clarify for yourself. That, of course, is a rare situation. I don't have a set of NFL rules here..........
Nonetheless,a good question.