The chance of error doesn't go below 10% even if we count the 163 utterances that do not contain references to CFs introduced in the previous utterance but are segment boundaries and therefore are not governed by the constraint.
if the vanilla instantiation were the "right" way of setting the parameters, we would have to conclude that in the genres contained in our corpus, utterances are very likely to have a unique CB, but entity coherence does not play a major role in ensuring that a text is coherent: only 35.4% of utterances in our corpus would be "entity-coherent," that is, would contain an explicit mention to an entity realized in the previous finite clause.