Using Solr’s Dismax Tie Parameter by Rafał Kuć.
From the post:
The Dismax query parser has been with Solr for a long time. Most of the time we use parameters like qf, pf or mm forgetting about a very useful parameter which allows us to control how the lower scoring fields are treated – the tie parameter.
The tie parameter allows one to control how the lower scoring fields affects score for a given word. If we set the tie parameter to a 0.0 value, during the score calculation, only the fields that were scored highest will matter. However if we set it to 0.99 the fields scoring lower will have almost the same impact on the score as the highest scoring field. So let’s check if that actually works.
Remember that the Solr Wiki defaults to title searches when you are looking for parameters. Choose the text button next to the search box.
For qf (Query Fields), pf (Phrase Fields), mm (Minimum ‘Should’ Match), and tie (Tie Breaker), see: the Solr Wiki DisMaxQParserPlugin.