Looking Beyond the Obvious
By Mike Lawrence

This was a case of playing too quickly at trick one. Declarer could see that the only thing that could defeat him was if West had five spades, could set them up, and could then get in to cash them. Had declarer ducked the opening lead, he would have retained his second spade stopper.

West can lead a second spade but now when East gets in, if he is able to continue spades, then they were divided 4-3, and are therefore harmless. And if spades are 5-2, East won't have another spade to lead. so South's spades will be safe.

As it is, South could still have made three notrump by guessing to play on diamonds before clubs. That would get West's entry out of the way before the spades were set up. Which minor suit to play on is just a guess which South had no way of judging. The easy solution is to avoid guessing games by allowing West to win the first spade trick.

IN FACT

This line can lose if East has five spades to the queen and both minor aces, but this is so odds against that you should not worry about it.