Affects Version/s: None
Fix Version/s: 5.3
You can see a full description there, but the gist is that SpanQuery sums up freqs with "sloppyFreq".
However this slop is simply spans.end() - spans.start()
For a SpanTermQuery for example, this means its scoring 0.5 for TF versus TermQuery's 1.0.
As you can imagine, I think in practical situations this would make it difficult for SpanQuery users to
really use SpanQueries for effective ranking, especially in combination with non-Spanqueries (maybe via DisjunctionMaxQuery, etc)
The problem is more general than this simple example: for example SpanNearQuery should be consistent with PhraseQuery's slop.