Ask HN: Does anyone know (or guess) how gambling apps make betting lines?

Was watching the NBA finals last night and decided to play around with the $5 that was in my Draftkings account when this question came to mind.

I imagine there is some API that a lot of the apps use for their lines. But super curious about how they make these just out of genuine curiosity, both for team matchups and player stat over/unders.

Think it would make sense to incorporate historical performance, maybe higher impact on recency like if a team/player is hot, maybe also a focus on player matchups, home-field advantage. Wonder if they incorporate who is reffing or other kind of more quirky factors?

Not building anything in this space just was curious. I envisioned that some gambling software legend lurks here sometimes and might bite at the poor question.