Noticing a pattern here?

"The most common strategy to surviving Night 6 is as follows:

Check Foxy and Freddy Fazbear (depends where he is. It is recommended to start watching him from the Show Stage.)
Check the Hall lights.
Repeat.

Alternatively, this strategy can also be employed:

Check only Freddy (Check him on the Show Stage).
Check the Hall Lights.
Check Pirate Cove every 2-3 cycles.
Repeat." noted from the FNAF Wiki

Hey sure, this can get you through sometimes. But, doesn't this seem a bit odd?
To the normal person, it does not. But to me, it strikes me as very odd indeed.

I'll tell you why.

One word : Luck.

If you ever play a FNAF game, you'll notice that there's really no specific path the animatronics will take,
(Some of them have patterns, but they take different routes every time.) and no night usually has the same
configuration. Because of this, strategies like this don't work all of the time, and there's a chance that it
may, or may not.

This becomes more apparent in the second game with the Marionette. How long you leave it before winding
it up is up to you, and can either save or break you. Don't get me? Okay, for example, say I wound it up 2 seconds
before it was going to come out of the box, and say Bonnie was 'unluckily' in the vents. It's luck whether I get jump scared by
Bonnie because the game decides when to jump scare me. Get it now? Yeah?

The third game? This has more skill involved, but luck can be a big factor too if you don't use the play audio button
often. Springtrap has a completely different route every time. But really, keep using that button and you'll be fine!