Understanding the score decay for repeated connections rationale

Question

Consider:

for _ in range(10):
    time.sleep(5)
    s = (Search(using=client, index='myindex')
        .query('match', title={'query': video_title, 'analyzer': "standard"}))

    for hit in s.execute():
        print(hit.meta.score, hit.title) # same score within one execution of the script,
                                         # but decreasing with each subsequent execution

As the comment says, the score is consistent within the same execution of the script, but decreases with each subsequent execution. (The index is kept same between the executions. Namely, the script adds a single document to the index, searches for this document 10 times and then deletes the document.)

What is the rationale that the score stays consistent for one connection, but decreases between the connections? How do I disable this decay?