200

South opens 1 spade. With only 9 high-card points, North can't do more than respond INT. Playing 2/1, the INT response is forcing, so south must find a rebid with the minimum balanced hand. South bids 2 diamond the longer minor.

North actually prefers diamonds to spades, but should not pass the 2 diamond rebid with this hand. There are two reasons. South could have only a three-card diamond suit, as on the actual deal. Also, South could have a medium-strength hand of about 17-18 points, not quite enough for a jump shift. So North should bid 2 spade , putting the partnership back into the known seven-card fit. This is technically referred to as false preference.

With a minimum opening bid, South accepts North's preference back to 2 spade and passes.