Specifically on last years chronics, the orange ones? when you say -2, do you mean measure the ski, cut that length in half, and -2 from it. Ex. 166/2=83 so 83cm is center, so 83-2=81 so the center of your boot and binding will be at 81cm from the tail and 85cm from the tip?
or is it something different? i did search, and i found like 6 threads dealing with core and true center, but they didn't help too much