Some other considerations; The host rock type can make estimations more or less difficult and improve or reduce the confidence level(s). The amount of reworking of the surrounding rock over time is likewise a factor. Thus knowing something of the intervals that are not sufficiently mineralized to warrent assaying is a consideration. The amount of fracturing of the Host rock is another factor. How much veining has there been. The holes that are near misses tell lots with respect to all of the above. One good thing about specialized Software is that you get to database your information and thus do not have to repeatedly relocate and compile it. Thus the real time saving aspect of Software. The single most problematic aspect of databasing in good (not all data base software is good and stability and transferability to other applications can be a headache etc.) software is the accuracy of the data entries. Just a few errors can cause very large errors in output quality and accuracy etc.. There are other issues with respect to setting correct (proper or reasonable) parameters and using reasonable assumptions etc.. Thus, the knowledge and experience of the individual using any method is the most important factor. So, nothing really new or foolproof. As with the SP so the other estimations of value - real or perceived. Time, effort, experience, knowledge, good data, application, interpretation, extrapolation, and all the other items (captured by buzz words often but important all the same) still create unpredictability but help provide reasonable expectations. Of them all I expect experience is of the best use if melded with good judgement. Old Joe PS: Time to get out and enjoy a very lovely day here in the Foothills as well as in the market place.