I once read somewhere that we shouldn't do what I always do----shuffle and lay out cards just idly or randomly instead of reading them every time as a reading. The supposed reason was, according to the one who wrote it, was that every spread we put out is a reading and that all the stuff that was in it will come to pass, so we need to only do a spread if we're doing a "real" reading. Boy, do I ever have some things coming to pass then!
We just have to remember that just because something is written in a book or article doesn't make it true. It's still someone's opinion of what the truth of a matter is. Like card meanings---what you read as card meanings is someone else's idea what a card means, and sometimes (lots of the time, I'm sure) they're just repeating what everyone else said. So I don't know about 75% of a bad reading being true----it may or may not be.
I used to wonder why people used past, present, future spreads when it's the future most people are wondering about. Well, one of the reason we do that is so that we can kind of gauge our success with reading what the cards are saying. If we get the past and present right, then chances are high that we're going to be right about the future, too. So, if you put out 4 cards, let's say, and three of the positions included cards about the past and present and you got those right, then 75% of the reading would be true.
All that is probably not very helpful.
Maybe 75% of it's helpful? lol