I think that stat-based metagaming is a natural thing. Then again, I'm generally a rather scientifically-oriented person and approach real life in a very similar way.
On the other hand, if you're doing "three encounters in a module" type thinking, you'd best be doing it QUIETLY, because if the DM catches you, you're going to find a 4th encounter really fast. As a DM, I love setting a player up like that: Do something. Over, and over, and over, as a sort of unspoken formula. Then throw it out. Confuses the hell out of them and instills a suitable sense of surprise and terror. Plus, even though I planned it all along, and knew it would happen, I can feign total innocence and blame the player for his own stupidity. That's what good DMing is all about: Knowing who to blame for when something goes south as planned.