Review

class ValueSourceQuery.ValueSourceScorer {
    /*(non-Javadoc) @see org.apache.lucene.search.Scorer#explain(int) */
    public Explanation explain(int doc) throws IOException {
      float sc = qWeight * vals.floatVal(doc);

      Explanation result = new ComplexExplanation(
        true, sc, ValueSourceQuery.this.toString() + ", product of:");

      result.addDetail(vals.explain(doc));
      result.addDetail(new Explanation(getBoost(), "boost"));
      result.addDetail(new Explanation(weight.queryNorm,"queryNorm"));
      return result;
    }

}