title: subquery scoring and coord in edismax ranking in SOLR
body: <p>I am using edismax ranking in solr 4.1. I have a queryparser which generates a few sub queries given a single query string. As I was looking at the specific ranking detail (by adding "debugQuery=on"), I found the followings:</p>
  
  <p>1> It looks like rank scores of all sub queries are added first
  2> And then there is a multiplication of this total score and coord factor. It looks like coord factor is the ratio of how many sub queries got match. For example, if a query turns into 3 sub queries and if only 1 of them gets hit, then coord factor would be 1/3. </p>
  
  <p>I am wondering 1> whether my observation is correct. 2> if so, whether there is a way to change these behaviour something like the followings:</p>
  
  <p>1> Instead of summing the scores of sub queries, just take the max score.
  2> Ignore coord factor. </p>
  
  <p>If current solr 4.1 implementation doesn't support, any pointer which source code to change or use as a reference would be great.  </p>