Johny, either you have never studied statistics/probability or your Mnemonics aren't working. One coin toss will yield either a head or a tail. This equates to your "Either a transaction is traceable or it isn't." But what about the set of a billion coin tosses? While each is either heads or tails the set in a normal distribution tends towards .5 of each. Majamina's excellent chart shows that for anything less than close to 100% of the masternodes compromised, the chance of tracing any single transaction is vanishingly small.