Things are a bit more complicated with user input data.
Your NBA SDQL:
sorted(list:p:points) [-1] >30
fails because there is more than one player-level table.
You can use the full form for player reference:
sorted(Player:list:p:points)[-1]>30
or, more simply:
Player:max:p:points>30
For more on player-level queries, please have a look at the manual page at:
best regards,
Joe Meyer
Sports Database LLC