The highest-ranked ones were believable as reliable instances of dependencies: infinitival to in VB TO seems likely to be often correct, as does existential there in the first three cases.
it is quite possible that many of the reliable ones such as PRP VBZ are actually poor at distinguishing between positive and negative examples by virtue of their frequency -they may occur equally often with both, in the same way that words like the are useless in general text classification.