The sweet spot does not = 100% chance of an item


Look at it like this

at the default spot you get

39% silver
40% iron
30% stiperstone
1% kidney ore

you bump it down to -4(kidneys sweet spot)

and it becomes

30% iron
30% silver
30% stiperstone
10% kidney


all the sweet spot is, is the best % chance to get that item, it doesnt mean its all you will get