As we all may know, mining can be very predictable, the energy bar has several stages, and depending on which sweet spot you are at, you can predict where to strike and what you will get. That theory was working just fine for me up until I moved up to the grade 5 nodes at iron lake.

For example according to most, If the energy bar is at stage 3(second from the lowest) assuming you are at the depth range of -4, Cobalt ore SHOULD be at 100-90% Striking power. But I have been getting it from 10-20% striking power, and at times neither 10% nor 100% yield any results. Pic for proof
http://i.imgur.com/o3pke.jpg
Disregard my lolattire.


So what my question is, have strike zones been ninja patched and have become randomized? or have I been looking over something that may factor in to the strike zone?