its newcrest, page-52

It was probably also a valid way to quickly establish an estimate of the size and tenor of the ore body in a way that after just a few holes they could promote the project to jv partners.
Remember that the big mining houses can be very risk adverse so that the 'pyramid' type drilling approach gives that confidence to the ncm exploration manger as he goes to the ncm board and says 'here, look what Frontier have confirmed at Andewa after just 4 holes. 300mt @ .4g/t Au equiv. And we know its a huge system therefore we should buy in' and the ncm board agrees.