Bayesian Programming and Learning for Multi-Player Video Games ...

Chapter 7
Strategy
Strategy without tactics is the slowest route to victory. Tactics without strategy is
the noise before defeat.
All men can see these tactics whereby I conquer, but what none can see is the
strategy out of which victory is evolved.
What is of supreme importance in war is to attack the enemy’s strategy.
Sun Tzu (The Art of War, 476-221 BC)
We present our solutions to some of the problems raised at the strategic level. The main idea
is to reduce the complexity encoding all possible variations of strategies to a few strong
indicators: the build tree* (closely related to the tech tree*) and canonical army compositions.
We start by explaining what we consider that belongs to strategic thinking, and related work.
We then describe the information that we will use and the decisions that can be taken. As we try
and abstract early game strategies to “openings” (as in Chess), we will present how we labeled a
dataset of games with openings. Then, we present the Bayesian model for build tree prediction
(from partial observations), followed by its augmented version able to predict the opponent’s
opening. Both models were evaluated in prediction dataset of skilled players. Finally we explain
our work on army composition adaptation (to the opponent’s army).
Build trees estimation was published at the Annual Conference on Artificial Intelligence and
Interactive Digital Entertainment (AAAI AIIDE) 2011 in Palo Alto [Synnaeve and Bessière,
2011] and openings prediction was published at Computational Intelligence in Games (IEEE
CIG) 2011 in Seoul [Synnaeve and Bessière, 2011b].
7.1 What is strategy? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
7.2 Related work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
7.3 Perception and interaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
7.4 Replays labeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
7.5 Build tree prediction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
7.6 Openings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
7.7 Army composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
7.8 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
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