There are some pretty hard and fast rules for deciding what card to lead from a suit. Which suit to lead from is, however, a matter of judgment. The factors you have to consider in choosing a suit include the auction (and what you learned from it) and then the availability or not of an attractive card to lead in the suits you are considering.
Sometimes you do not have a good lead. Some times you have a good lead but it isn’t one you’d be likely to choose. Sometimes you have what look like two good leads and one is great and the other one not great. Nobody is going to make a good lead every time.
Before we get into opening leads we should note that these suggestions for opening lead do not carry as much weight later in the hand. The most dramatic of these cases is mentioned in the section on leading Aces: you never underlead an Ace in a suit contract on opening lead, but it is quite common to do so later in the hand.
Standard Opening Leads¶
There is a table on your convention card in the bottom left that shows the card to lead from a variety of honor combinations. You should memorize these. As an example of how to read the chart, under “versus Suits” one line says K T 9 x. The bold T means, from a holding of King, Ten, Nine, and one or more small cards, lead the Ten.
If you and your partner agree to have a different lead from this holding, say the Nine, then you circle the Nine on your cards.
Lead The Queen? Really?¶
Under “versus Notrump”, there is one very odd entry. It says to lead the Queen from KQT9. Why lead the Queen? (Before you do, remember you need the 9.)
Let’s say your partner leads a Queen against notrump. It is likely from a suit headed by the QJT or QJ9.
But say you look at your hand and find you are holding the Jack! How could he lead the Queen without the Jack? It must be that weird lead from KQT9. What do you do?
Without a moment’s thought, play your Jack under the Queen. That’s the whole purpose of leading Q from KQT9: it asks partner to drop the Jack if he has it. Let’s say you have J653.
Suppose you mistakenly play the 6 (high to show you have an equal honor to his). Declarer plays low.
Now partner does not dare lead another card in this suit. For all he knows, Declarer has the Ace and the Jack. Leading again will make the Jack good. Declarer’s ducking the first trick is a famous play called the Bath Coup. If the suit is continued he gets two tricks instead of one. Lay out the cards and try it.
If, however, you play the Jack under Queen on trick one, your partner knows he can continue the suit until declarer takes his ace, and thanks to his 9 he has three tricks in the suit, maybe more if he has a fifth card.
Once in a while you have the Ace, in which case you play it, and if you have both the Ace and the Jack your partner has made a desperation lead from Qx, I’d bet. He is hoping you’re long in that suit.