We introduced index sorting in Elasticsearch 6.0 to help optimize cluster performance. Did you know that in some use cases, it can also help save space?
Find out how similarity ranking (relevancy) is impacted in Elasticsearch by the amount of shards in your index.
Learn more about how BM25 works by exploring the equation, variables, and concepts behind the default similarity ranking algorithm in Elasticsearch.
While there are no "best values" for b and k1, there are best practices and research data that should be considered before tuning these BM25 components.