f">Auer, Cesa-Bianchi &amp; Fischer (2002)</a> and <a href="http://ggp.stanford.edu/readings/uct.pdf">Kocsis &amp; Szepesvári (2006)</a> show that with enough simulations, mostly exploiting the best known move but occasionally showing optimism for less-explored moves, the results of the search converge to those of minimax, as used in classical engines. The upper confidence bound (UCB) metric is used to quantify exactly how optimistic to be and still converge. It would be dangerous to explore too much becau