Without diving into the code, can you tell us the algorithm? Does it scale based on upvotes? Such that a 200 vote story is harder to kill than 70? Or is it just

Without diving into the code, can you tell us the algorithm? Does it scale based on upvotes? Such that a 200 vote story is harder to kill than 70? Or is it just that once a story passes 50 upvotes it can't be programmatically killed?