okay, so when a player DNF's in a round that they would have shot 59 points below their rating it artificially skews the data (even more so if the sample size of propagators is small). every system has its vulnerabilities -- even [y]ours -- right?
No, because 59 points low is within the normal variation a player of any rating might shoot. It would be hard for a player to precisely calculate what they need to shoot 59 points low. And why would they try? They would be kicking themself for not playing bad enough to have the round dropped and not affect their rating. So a 59 pt low rating is more likely legit than deliberate.