Possible change of tie breaker behavior between Solr 4.4 and Solr 6

[Christian Ortner <ch...@gmail.com>]

Hello everyone,

We're in the process of upgrading a service from Solr 4.4 to Solr 6. While
comparing result quality between the two versions, I found that a result's
phrase query score now contains the highest scoring field. In Solr 4.4, the
sum of all matching fields' scores was added to the total score.

This behavior looks similar to how a tie breaker set to >0 impacts regular
queries, although this does not appear to be documented. Is it possible
that such a change was introduced between 4.4 and 6? I checked the change
logs and documentation to no avail.

Thanks!
Chris