That situation is an exact analogy to some situations in chess.

Ever have someone say "Mate in 5" and you may think, "no one can see 5 moves ahead, the branching probabilites are damn near infinite"

But when you FORCE a move, it's easy . But you really aren't seeing 5 moves ahead. You are giving him 2-3 VERY necessary choices which lead to the final 2-3 true "mating" moves.