[levythe]

It's typically considered the best approach to cast a broad net, then narrow down until a patent is granted. That being said, in the US, patents are given on a first to invent basis, so if you are awarded a patent that is overly vague, it's pretty likely it won't hold up if challenged. I find myself questioning the value of a patent office that awards patents that are vague enough that they wouldn't hold up in a dispute.

[jacques_chester]

In my understanding the US is now on a first-to-file system.

[cma]

Yes, but a publication or public disclosure that happened before has precedence over a filing.

[mehrdadn]

Apparently it's first inventor to file, though I'm not entirely clear on what that means.