We currently only sort our WF. We use the NMI in the mill to sort it, wich I am pretty sure sorts it by moisture content, going by the weight. Currently we run about 70% hrt, and 30% sap. Sometimes it will fluctuate. I have done some research, and had some help from guys in here, and it seems to me, the best way to sort green lumber is to sort it by density, not Moisture content. I am pretty sure this would be your best bet. If you have two boards, and one is 80% m.c. and the other is 50%, but they have the same density, they will dry at around the same time. If you have 2 boards that are both the same or close moisture content, but the density is alot different, then they will not dry well together.