Jeremy,

By default examine well to be more specific lucene orders by score. If you order by any other field then the will be set to NaN as you can see in your screen shot. I am not sure why it does whether its lucene that does it but my guess is because you are setting the sort it ignores it.

Regards

Ismail

More reading https://stackoverflow.com/questions/20541188/explain-scoring-in-lucene-while-sorting-involved

I ended up sorting using LINQ:

List<int> nodeIds = results.ScoreDocs
    .Select(x => int.Parse(searcher.Doc(x.doc).Get("__NodeId"))
    )
    .ToList();

output.Results = nodeIds.Select(x => x).OrderBy(x => GetNodeName(x)).ToList();

is working on a reply...