Someone challenged me to trace his transaction to its source yesterday on Bawdy Anarchist's twitter space and I denied the ability to do so. I want to build more automatic decoy eliminators because without them you need lots of off chain data that I don't know how to get or that is expensive to acquire. I am not sure how far you can get using only chain heuristics to identify the true spender; I suspect it's higher than 1 in 15 but lower than 100%. One monero dev offered a helpful cli tool that detects all instances when a stealth address has appeared in a ring; this is something my tool is currently missing and would greatly help with building taint trees. I hope that through community effort my tool continues to improve in effectivelness. The bad guys shouldn't be the only ones with a tool like this, and before yesterday only ciphertrace had a tool like this (that I know of anyway)