They're referring to scores on individual COMMENTS - this information isn't available via the HN Firebase API.

The only way you could theoretically extract everyone's comment scores (at least the top level ones) would be like this if you're a complete madman:

1. Wait 48 hours so the article is effectively dead

2. Post a new comment using an account called ThePresident

3. Create a swarm of a thousand shill user accounts called Voter1, Voter2, etc.

4. Use a single account at a time and upvote ThePresident

5. Recheck the page to see if ThePresident has moved above a user(s) post

6. Record the score for that user and assign it to the tracked story's history

7. Repeat from (4)

I know that! I have a collaborative project to make it sort of available.

But the idea I have is not like that at all - it's much nicer on everyone's ethics. Stay tuned! :)