Hmmm, "sheriff stars" to both translationsmru and Bitpicker for their answers -- аs a native speaker of English, I really had no idea how to answer Lena's question, but I thought the subject/object analysis was very logical!
Двадцать очков Гриффиндору...
I have to confess that while I never had any problem with such phrases I had to look up the reason why it is like it is in a grammar book. It's a distinction I had never really thought about before.