Cave downs and black tiles

Hello,
I'm just wondering if M&M affects chance of Cave down happening.
Does higher or lower makes cave down occur easier? Or it doesn't matter?
And also if it doesn't matter what's aprox. chance of cave down happening?
I'm just wondering if M&M affects chance of Cave down happening.
Does higher or lower makes cave down occur easier? Or it doesn't matter?
And also if it doesn't matter what's aprox. chance of cave down happening?