A preliminary conclusion is that the best estimates are obtained when only blasts or, alternatively, blast-and drill holes are used; there is no significant difference between the two, which is due to the great amount of blast information. This result justifies the usual practice of basing short-term planning on blasts only. But another conclusion may be drawn when kriging is compared to a moving average (another common practice), both based on blasts: depending on the number of data used in the neighborhood, the moving average produces a strong conditional bias. As a byproduct, we also show how it is possible to filter the blast error by kriging and to make a deconvolution to estimate point-support values using blast measurements.