I was reading some literature (Palinuro de México) and found an interesting example. One of the characters shoots empty bottles for fun and he is 100% accurate (he says: "I'll hit this bottle", and then he shoots and always hits); when asked how can he be so accurate, he says that his trick is to always aim for the bottle next to the one he wants to hit.
The question here is if someone can be said to act intentionally even though, when he acts, he is trying to do something else, his attempt is unsuccessful. and this failure causes the result he wants.
What if he 'misses' his shot and hits the bottle he's aiming at, did he intentionally hit that bottle? If someone tries to G and he succeeds, you seem to have enough reasons to say that he G'ed intentionally, but if you answer yes to the first question, you have to say that this is not enough. This seems to imply that intending and trying are only contingently connected, but this sounds really weird.