That guy who's really good at making a detailed plan for winning at Monopoly? He's a strategist, or an expert at strategy, or planning.
The noun strategist is most commonly used to talk about military people who plan wars, but it's useful whenever you mention someone who is particularly good at making a plan in any kind of complex situation. A coach acts as a strategist when she makes a plan to help her team win the game. A busy mom could also be called a strategist when she has a system for getting a bunch of kids fed, clothed, and out the door to school on time.
