As you gain experience in a given area of the country, you will
eventually learn what they like to do in that particular part of the
country. Then you can get to a point where you can guess what's coming
maybe three times out of four. That's it. Your chances of getting
cleared as filed in busy airspace you're unfamiliar with are
effectively zero. The only time you can get what you want, you can
also get direct. The stuff in the A&FD is worthless.

You shouldn't just file direct because, well, you just shouldn't. It
will make Don Brown mad. It will make your CFII wonder why he spent
all that time teaching you about choosing routes.

Actually, when I don't feel like trying to outguess the controllers,
that's exactly what I do. At best, I'll throw in a couple of fixes
along the route so that every controller can have a couple of fixes he
recognizes.

In real life, controllers assume you have a GPS and can go direct to
any fix. They don't care if the GPS is IFR approved because they can
only approve GPS direct when they can provide RADAR monitoring, and
there's no regulation covering what you can and can't use for enroute
nav anyway.

Michael