User blog comment:Amabo Kcorb/Does anyone know the mechanics of the skill, Dig?/@comment-44863604-20200831055126

The mechanics for the move dig as far as I can tell appear to be all located in Common Event 0032 and Common Event 0117 which you can see for yourself inside your in the Script folder made by the translation software.

>>> ChangeVariable(11,11,0,2,1,100)

Both events begin with a function which I believe randomly assigns a value to variable 11 between 1 & 100...

'''If(1,11,0,30,2) ShowMessageFace("",0,0,2,1) ShowMessage("You didn't find anything.") EndEventProcessing 0 EndIf'''

The event then goes through a line of if statements arranged from low to high,  which if the value of variable 11 falls with the range of the if statement, which if true will lead to that result.

'''If(1,11,0,100,0) ShowMessageFace("",0,0,2,11) ShowMessage("You dug up something shiny!") ShowMessage("It's a \\ii[32]!") ChangeInventory_Item(32,0,0,1) 250(  ***Omited*** ) ShowMessageFace("",0,0,2,12) ShowMessage("You obtain \\ii[32]!") EndEventProcessing 0'''

The Shiny Medal outcome is last in the sequence and apears to only trigger if the value of Variable 11 is at least 100.

Since the difference between Common Events 0032 and the 0117 seem to only effect the outcome of the Mandragora encounter, you have the same chance of obtaining a Shiny Medal no matter which variant of the Digging Event activates. So doing the math we have:

(1/1)(1/100)= 0.01= 1% chance of getting a Shiny Medal any time you use the move dig.