Why does the "boost" not affect the score?

1_setup.txt

## In the 2 queries below, the documents have the same score, despite the 2nd query having a boost.

curl -X DELETE 'localhost:9200/test?pretty=1'

curl -X POST 'localhost:9200/test/foo?pretty=1' -d '{ name: "Nick Hoffman" }'
curl -X POST 'localhost:9200/test/foo?pretty=1' -d '{ name: "John Smith" }'
curl -X POST 'localhost:9200/test/foo?pretty=1' -d '{ name: "Nick Other" }'

curl -X POST 'localhost:9200/test/_refresh?pretty=1'

2_query_with_no_boost.txt

curl 'localhost:9200/test/foo/_search?pretty=1&explain=0' -d '{
  "query":{
    "dis_max":{
      "queries":[
        { "text": { "name": { query: "Nick" } } }
      ]
    }
  }
}'

{
  "took" : 2,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "failed" : 0
  },
  "hits" : {
    "total" : 2,
    "max_score" : 0.19178301,
    "hits" : [ {
      "_index" : "test",
      "_type" : "foo",
      "_id" : "-EZKwqUsRzqy4uh1AeVGnA",
      "_score" : 0.19178301, "_source" : { name: "Nick Other" }
    }, {
      "_index" : "test",
      "_type" : "foo",
      "_id" : "AEq9G1THQG6EAADy7ewFAQ",
      "_score" : 0.19178301, "_source" : { name: "Nick Hoffman" }
    } ]
  }
}

3_query_with_boost.txt

{
  "took" : 2,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "failed" : 0
  },
  "hits" : {
    "total" : 2,
    "max_score" : 0.19178301,
    "hits" : [ {
      "_index" : "test",
      "_type" : "foo",
      "_id" : "-EZKwqUsRzqy4uh1AeVGnA",
      "_score" : 0.19178301, "_source" : { name: "Nick Other" }
    }, {
      "_index" : "test",
      "_type" : "foo",
      "_id" : "AEq9G1THQG6EAADy7ewFAQ",
      "_score" : 0.19178301, "_source" : { name: "Nick Hoffman" }
    } ]
  }
}