Hi Gambit. You should be able to tell exactly how many pins this has. Try taking a half diamond pick and flipping it upside down. Then insert the pick all the way to the back and lift the pick to the top of the keyway. Then slowly slide the pick out and count the pins as they drop.
It is important that you know how many pins are in the lock, or you will never have any idea what is going on inside when you pick. Sometimes you can get lucky and just "poke around" in there and eventually the lock will open, but if you rely on this level of skill, you will be a sad and frustrated picker.
It is vitally important that you have a solid understanding of what is going on inside the lock, and that you can recreate that information in a picture in your mind. Picking is most effective when you can visually recreate the states of the pins based on feedback you receive via sound and feel from tools. The first step in this is to know the number of pins.
Once you have counted the pins (should be a first step whenever you pick up a new lock) work on really paying attention to the states of the pins as you go. If there is, in fact, a security pin you may find this lock a little hard to begin with, though not necessarily. IF you get totally frustrated with this lock, put it down for a while and move on to a different lock for a bit.
Good luck, and happy picking!
db