I do understand why some people don't see sense in the centre tear. But then how many effects are completely clean? Indulge me, please, in my discourse in support of the centre tear...
If I want someone to select a card freely why would I ask them to cut to a card, or push a finger into the deck as I riffle it? They should be able to pick up the deck, look through it and pull a card out. But I don't usually ask them to do this. I'll ribbon spread at best (face up or down), and that seems incredibly fair to most people. As it happens, I really don't like the riffling force methods.
The performer is always 'in charge', sometimes making up the rules as s/he goes. This is what makes PATEO etc possible. And very few people seem to question the strange acts that they are asked to perform (jinx to Bingo).
For example, there have been many times when I've been performing (funnily enough, usually in small and informal situations - which seems counter-intuitive) where the participant has been concerned that they are doing things properly - that they want to follow the 'rules'. They assume the existence of rules and they want me to tell them these rules so they can comply. My guess is that few people have first hand experience of being part of a 'magic trick' and want to get it right (*anecdote follows). Writing this I almost can believe in hypnotism. But...
Getting back to the CT specifically... you've had someone commit an idea (word, usually) to paper. This is a significant act. You then destroy it, which is also significant. The whole thing is a drama and hopefully the audience buys into it. "He destroyed the paper - now it's *really* going to be tough to know what Fred was thinking!"
Reasons for the CT (i.e. why write and destroy)?
- My personal one - spies. My usual material is about espionage, so destroying a message is entirely appropriate. It's a fun part of the story.
- Voodoo (as someone said earlier) - burning stuff is ritualistic. That will fit with a lot of bizarre stuff, which is hardly the most rational area of entertainment ever created.
- Other stories. If you have a theme you can probably work destruction into it. Eugene Burger's treatment of the Hindu/Gipsy thread fits this idea. Tell a good story and you've gone beyond a point where someone will say, "OK, but why did he shred the paper?"
Just my late evening thoughts in support of the mundane CT.
* Here's the anecdote.
I'd bought some fair-looking ESP cards (Beyond ESP 2) and was mucking around with them in a London bar one evening. I'd got cocky and had five people lined up (jinx to Bingo), each with a card. I got the first right but, due to the terrible lighting and my inexperience with these cards, I failed at least two times (maybe three).
My final attempt succeeded. The old bloke, whose card I has revealed correctly, exclaimed loudly. To my surprise he said, "YES! I got it right!" Read that again - HE got it right! I had asked them to transmit the image to me and he'd seen my previous failings not as my problem but as the failing of the other participants. He believed he'd succeeded. Mad I know, but an interesting experience for me. Someone really bought it...