In an online teams game, after North’s game-forcing response, South decided to show a balanced shape by his two-no-trump rebid. I agree with his choice — a three-club call should deliver extras or a fifth club (or both). Without a spade stopper, the decision would be far harder — especially if you play that a two-heart rebid promises six. When North sensibly withheld his heart support, the best game of three no-trump was reached.
West led a low spade to East’s king, and back came the spade jack to South’s queen. Declarer next led a heart to the queen and ace, after which East cleared spades as South shed a diamond from hand. Declarer got the bad news when he cashed the heart jack, and now, counting only eight tricks, he decided he needed a diamond winner for his contract. He played one to the king, hoping that East had the ace or that West had started with only four spades. That line failed today.
East’s spade jack continuation had flagged the 5-3 spade split, and the bidding had placed the diamond ace in the West hand. (East would have opened if he held the spade king and jack and both red aces.) Thus, declarer’s plan was slated to fail. Had he instead run the clubs, West would have come under intolerable pressure. Two diamonds can be discarded without pain, but the fourth club trick proves too much.
To keep both red suits guarded, West must shed a spade winner, letting declarer exit with a diamond. West takes his spade but then has to lead around to South’s heart K-9 tenace at trick 12, conceding the contract.