  This paper summarizes the AAIA'17 Data Mining Challenge: Helping AI to Play
Hearthstone which was held between March 23, and May 15, 2017 at the Knowledge
Pit platform. We briefly describe the scope and background of this competition
in the context of a more general project related to the development of an AI
engine for video games, called Grail. We also discuss the outcomes of this
challenge and demonstrate how predictive models for the assessment of player's
winning chances can be utilized in a construction of an intelligent agent for
playing Hearthstone. Finally, we show a few selected machine learning
approaches for modeling state and action values in Hearthstone. We provide
evaluation for a few promising solutions that may be used to create more
advanced types of agents, especially in conjunction with Monte Carlo Tree
Search algorithms.
