Chances of Finding Something by Chance

I'm curious what the chances are of finding something of value without using x-ray; i.e. digging down randomly.
Since I do not know, and I believe that chances are slim that someone has a definitive answer, let's do some science!
Since the wild was recently reset, I took the opportunity to collect Mining Data in the wild.
This has some value as to provide some insight as to X-Ray prevention.
Setup: Dig straight down in random locations. Inventory was documented.
Mining Data:
Site 1:

Site 2:

Site 3:

Site 4:

Site 5:

Site 6:

Site 7:

Site 8:

Site 9:

Summary:

I'm curious if you guys agree to this mining data.
Also, I will admit that I was never using X-Ray during the entire study.

 

An experiment of this scale with 9 samples?

You'll need to do atleast 10 times as much "Sites" to have atleast close to reasonable data.

 

I have to fully agree that we need more data.