If you were playing chess and could do whatever you wanted, you could take several goes in a row, take the opponents pieces off the board and move yours into a winning position. How does that help you play better under the constraints of the rules?
This metaphor doesn't really work because the entire point of a game—the thing that makes playing it playful—is that it has no effect on the world outside of the game itself. Thus, ignoring the rules of chess to reach a goal doesn't make sense. There are no chess goals that don't involve the game of chess.
This isn't true in programming or real-world tasks where you are trying to accomplish some external objective.
If you were playing chess, and you could do whatever you wanted, you might want to, e.g., set up a beautiful mating combination using the minor pieces, set a brilliant trap with forced mate in 10 moves and then trick the opponent into falling into it, keep control of the center all game and make the opponent play in a cramped and crippled style, promote a pawn to a knight for a win, skewer the queen and king, or turn a hopelessly lost position into a draw. The constraint is: you need to take turns and the opponent wants to win / doesn't want to let you win.
