Try not to slip up early in the play

Jean-Paul Sartre said, "Three o'clock is always too late or too early for anything you want to do."

I suppose that's right. It is too late for a nap, too early for a glass of wine - ah, it is not too late to buy or sell shares in the stock market, unless you are in the Mountain or Pacific time zone.

At the bridge table, though, trick one, two or three can be too late to save your contract. In this deal, how should South play in three spades after West leads a low heart?