Expectiminimax
= Expectiminimax
= Expectminimax
{synonym}
<Backward induction> on a finite <game tree> containing maximizing choices, minimizing choices and <chance nodes>. Terminal <utilities> are backed up by $\max$, $\min$ and $\sum_jp_jV_j$, respectively. Exact <chance node> evaluation generally needs every positive-<probability> outcome; ordinary <alpha-beta pruning> does not transfer unchanged because one child's value does not bound the full weighted sum.