Can someone explain how cut-off grade works. I'm trying to do some comparisons with some other 43-101's. Below is a table of the 43-101 results from Black Thor. The resource estimates vary a lot based on cut-off grade. Black Thor has over 69.5 million inferred at cutoff of 25%. But it falls way off to just over 36 million at 30%.Here is the table:

The Black Thor chromite deposit contains an Inferred Mineral Resource of 69,554,960 tonnes grading 31.9% Cr2O3. The details of the mineral resource estimate are as follows:

Classification

Tonnes (millions) %Cr2O3 Cut-Off Grade

(% Cr2O3)

Inferred Mineral Resources 121,883,768 27.8 20%

Inferred Mineral Resources 69,554,960 31.9 25%

Inferred Mineral Resources 36,062,976 36.1 30%

Inferred Mineral Resources 16,710,037 40.46 35%

Here is a table for Black Creek.

The following table summarizes the Black Creek chromite mineral resource estimate at a cut-off grade of 30% Cr2O3:

Note that PRB uses a cutoff of 30%. Why does PRB use cutoff of 30% for BC while BT uses 25%? I am wondering if PRB were to use cutoff of 25%, what would the results be. At Black Thor, the resource is almost double at 25% cutoff compared to 30%.

Just wondering if anyone can clarify this.

Also, here is a link to Bid Daddy 43-101. http://www.spiderresources.ca/shareholder-reports/NI-43-101-2010.pdf

On page 9 and 10 are two separate tables. One uses a cut-off grade as low as 15%. The other, (the first one) didn’t even give a cutoff grade, (not that I could find anyway.)

I am thinking that if BC is using a higher cutoff grade in its 43-101 compared to BT and BD, then is BC possibly more valuable per ton than the others. I am not a geo type so would very much appreciate it if anyone can help clarify this. Maybe this is not that big of a deal, but if it is, it would be nice for all to know about it.

Thanks, Profitz