ElasticSearch full text query (using multi-match) need to give more importance to document which starts with matched word

[saikirant (Saikiran Thunuguntla)]

I have 2 documents whose fields are as follows.

Doc1: "Identity Vijay"

Doc2: "Vijay Identity"

When I search for 'identity' both documents are appearing with same score. Ideally I want 'Doc1' to have higher score as 'matched' word is at beginning. Is there any option in ElasticSearch to solve this use-case.

I am using a custom-analyzer and indexing documents.

I use a multi-match query for matching multiple fields.

Note: Is it possible to have higher score for exact matches. (E.g 'Identity' should have higher score than '--identity--' even though once tokenised their terms are same).

Mapping to create index -> Using a Custom analyzer.

curl -X PUT "localhost:9201/custom_index?pretty" -H 'Content-Type: application/json' -d'
{
  "mappings": {
      "vertex": {
        "properties": {
            "datatype": {
              "type": "keyword",
              "index": true
            },
            "name": {
              "type": "text",
              "analyzer": "custom_analyzer"
            },
            "title": {
              "type": "text",
              "analyzer": "custom_analyzer"
            },
            "description": {
              "type": "text",
              "analyzer": "custom_analyzer"
            }
        }
      }
    },
    "settings": {
        "analysis": {
          "filter": {
            "custom_filter": {
              "type": "word_delimiter_graph"
            }
          },
          "analyzer": {
            "custom_analyzer": {
              "filter": [
                "custom_filter",
                "stop",
                "lowercase"
              ],
              "tokenizer": "standard"
            }
          }
        }
    }
}'

Inserting documents

curl -X PUT "localhost:9201/custom_index/vertex/1?pretty" -H 'Content-Type: application/json' -d' {
    "datatype" : "hive_column",
    "name" : "Identity Vijay",
    "title" : "",
    "description" : ""
}'

curl -X PUT "localhost:9201/custom_index/vertex/2?pretty" -H 'Content-Type: application/json' -d' {
    "datatype" : "hive_column",
    "name" : "Vijay Identity",
    "title" : "",
    "description" : ""
}'

Search term-> "Identity"

Search query

curl -X GET "localhost:9201/custom_index/_search?pretty" -H 'Content-Type: application/json' -d' {
  "size" : 25,
  "query" : {
        "multi_match" : {
          "query" : "identity",
          "fuzziness" : "AUTO",
          "fields" : [ "name^2", "datatype", "title", "description" ]
        }
    },
  "from" : 0
}'    

Any help greatly appreciated.