How does the Elasticsearch compute the _score on Completion Suggest? Why my score is not equal weight?

Question

According the Elasticsearch Document, https://www.elastic.co/guide/en/elasticsearch/reference/6.7/search-suggesters-completion.html, the score is the weight?

I create an example like this, the weight is 5

POST music2/name
{
    "suggest" : {
        "input": [ "百频", "bp","baipin" ],
        "weight" : 5
    }
}

but when I query, I get result like this:

   "suggest": {
      "my-suggest": [
         {
            "text": "百度视频",
            "offset": 0,
            "length": 4,
            "options": [
               {
                  "text": "百度视频",
                  "score": 65
               }
            ]
         }
      ]
   }

the score is 65, How does it computed? Why not equal weight?

Thanks very much!