It's always been one of those features that sounds good in your head, but never works in practice, except when you're playing chess. They NEVER get used, and if

It's always been one of those features that sounds good in your head, but never works in practice, except when you're playing chess. They NEVER get used, and if by chance they do, they are so wildly inaccurate, because you've forgotten about it in the meantime.