Sorry, but my education says that you're wrong. Although you are right that the odds of the 101st flip being 1/2, the odds of getting tails 101 times in a row is (1/2)^101, or roughly 1 in 2535000000000000000000000000000. Same with dusties. As somebody already said, if the odds are 1/50,000, after killing 50000 of them, the odds of NOT getting one is (1-[1/50000])^50000, or (49999/50000)^50000. Either way, after 50K kills (assuming the drop rate is 1/50000), the odds of NOT getting a chain are 36.79%, making the odds OF getting one is 63.21%. But the figure I've heard most often is a 1/16000 chance. If those are the odds, then after 50K kills the odds of NOT getting one are (1-[1/16000])^50000, or (15999/16000)^50000, which equals 4.39%, or a 95.61% chance of getting one. the chances u get a d chain is 50% u get it or u dont get it and just like the coin the drop has no memory u just dont get it that much but every time u kill one u have a chance of 50% of getting it cuz u get it or u dont.