An important claim about $\backslash$alpha $\backslash$beta pruning states that with good ordering of nodes search depth can

be doubled. Imagine that there is an oracle which always picks the best branch for expansion, i$.$e$.$ the

one the guarantees most pruning. Label the nodes on the tree below by order of node picking that would

guarantee maximal pruning, i$.$e$.$ the first node $($the root$)$ should have label $0,$ the first child should

be labeled by $1$ and, the next node to be considered by $2,$ etc. Is there a condition on node ordering

that guarantees most pruning in a general case, i$.$e$.$ a condition that could be applied to any game tree?