Possibly a poor choice of words by @Rachscher with using the...

Possibly a poor choice of words by @Rachscher with using the words "probability" because this is exploration and there is only ever a possibility of success, some people read the words "probability" as having an inherent likelihood of success. I prefer possibility as a better choice of words because the implication is that a lack of success is common, otherwise, there would be orebodies everywhere, they are rare and difficult to find things. Finding something isn't guaranteed in mineral exploration, I can guarantee you one thing though if they don't drill any metres, then they are guaranteed to have a 0% chance of success.

Do you realize that they are drilling in the Eastern Mt Isa fold belt? And that package of rocks has produced some other known deposits. As to whether what they might find is substantial or not, exploration works by finding something first, and then further drilling proving that its substantial or not substantial, as the follow-up drilling happens.

You still haven't answered my question as to why an exploration company would just give up and go home after 12 months of exploration. In NW QLD a nominal 12 months of exploration is actually about 8-9 months of exploration boots on the ground due to the effects of the wet season, so just wanted to clarify if that's your position on exploration or not? They had initial good intersections at Brumby Ridge and all the follow-up drilling has demonstrated that there could be issues in continuity or more complex geology than expected but their initial exploration approach was valid and the follow-up drilling to prove/disprove various hypothesises has been a pretty standard exploration approach that many in the industry would have also done. So they were incredibly lucky to get the first high-grade hits and then incredibly unlucky that follow-up drilling couldn't find any continuity or easy explanation so far. If you don't think luck plays at least a small part in mineral exploration then god help you.