I would like to ask why is the player's decklist missing in the data? Evaluating game state rating without any information about possible future cards may give poor results. What I mean is building AI, that ignores it's deck content, while opponent is using this information, is hard to imagine to be successful unless it is used only in random decks format.
this is indeed an important remark. We didn't log the information regarding the remaining cards in player's deck because we did not feel that it is useful for our players. However, this is definitely something worth doing for the future.
Nevertheless, in this competition, you will have to manage without this information :-)
Am I correct that the same stands for secrets? I could not find information about opponent current secret count (this is very important).
Also, hero_card_id is not very self explanatory (although it can be guessed what it represents).