Yes, I can see. I suppose it makes the logic easier but I wonder if it's accurate.
I'm sorry, but your thinking doesn't make sense. A definition only needs to be valid, there is no notion of "accuracy".
Given the set S of legal states s in chess where white is to move, each s of which has a non-empty set of legal moves M(s), a deterministic strategy for white is a mapping f from S where f(s) is always a member of M(s).
That definition is valid because it determines whether something is a deterministic strategy for white or not.
@6488
Let us go back to your own previous post @6445:
"Alpha–beta pruning is a search algorithm that seeks to decrease the number of nodes
that are evaluated by the minimax algorithm in its search tree."
"It stops evaluating a move when at least one possibility has been found
that proves the move to be no better than a previously examined move."
++ 1 Nh3 is no better than 1 Nf3. 1 e4 e5 2 Ba6? is no better than 1 e4 e5 2 Nf3
"Such moves need not be evaluated further."
++ Thus 1 Nh3 and 1 e4 e5 2 Ba6? need not be evaluated further.
"When applied to a standard minimax tree, it returns the same move as minimax would,
but prunes away branches that cannot possibly influence the final decision."
++ The branches 1 Nh3 and 1 e4 e5 2 Ba6? cannot possibly influence the final decision.