for crying out loud guys......
the pins bind in a certain order - it doesn't have to be 1,2,3,4,5 - it could be 3,2,4,1,5.
so when you've got the first three pins in, then the first pin picks fine - so just say the order is 1,3,2 - but when you add the 4th pin it binds first because that hole always bound first - it just didn't have a pin in it. so the actual binding order is 4,1,3,2.
if you try and pick the lock the opposite direction, the order will be 2,3,1,4.
it's a common question as for some reason most people assume that the pins should bind from front to back or vice versa, but this is most often not the case. I believe the reason for this is that the holes are drilled individually and not with a 5 drill bit mechanism - if they were drilled simultaneously, then the pins would always bind in order.
the skilll required with single pin picking is identifying the state that each pin is in and acting accordingly.
the four pin states while applying torque:
-------------------------
1- normal pin at rest
springy up, springy down
leave this pin alone, or increase pressure if they're all at rest
2- driver jammed in shear line (ready to set, or false set)
feels stiff / security driver turns cylinder 'backwards' when lifted
this pin is ready to be set
3- key pin jammed in shear line (false set)
stiff, key pin does not return down with gravity or tapping
start over, or reduce pressure / turn the cylinder back a tiny bit with your pick until the key unjams (reverse picking)
4- driver at rest above shear line (set)
moves up with no resistance, stops hard, then falls back down limply. turns cylinder 'backwards' if forced. rattley.
this pin has done his duty, let him rest!
enjoy! and don't get discouraged by flames. scold is all bark and no bite.
except perhaps his own thumb for some reason....
Ok, let me try something a tad more helpful, perhaps. 
