The Rule of Eleven: A Defence Explainer

You are East. Partner leads a small card against a no-trump contract, dummy plays low, and now you must choose. Do you win with the ace? Duck? Play the ten? The Rule of Eleven gives you a count that turns guesswork into a plan. It is not a secret system; it is simple arithmetic, and it is one of the most practical tools a defender can carry.

What the Rule of Eleven Actually Says

When partner leads a card that is fourth highest in their suit, subtract the value of the led card from 11. The answer is the number of cards higher than the led card in the other three hands: dummy, your hand, and declarer's hand. Since you can see dummy's cards and your own, the rule tells you exactly how many higher cards declarer holds.

Suppose partner leads the seven. 11 minus 7 is 4. There are four cards higher than the seven in dummy, your hand, and declarer's hand. If dummy has one and you have two, declarer has one. That is the whole idea.

The arithmetic works because a fourth-highest lead guarantees that the leader holds exactly three cards higher than the one led. The rest of the higher cards must be in the other three hands. The rule simply counts them for you.

A Worked Example

Partner leads the six. Dummy has Q 10 4. You have A 9 3. 11 minus 6 is 5. There are five cards higher than the six in dummy, your hand, and declarer's hand.

Dummy holds the queen and ten, two cards higher than the six. You hold the ace and nine, another two. That accounts for four of the five. So declarer has exactly one card higher than the six.

Dummy plays the four. What should you play?

If you play the nine, declarer needs a card higher than the nine to beat it. Since declarer has only one card higher than the six, it might be the king, the jack, the eight, or the seven. If it is the king or jack, declarer wins. If it is the eight or seven, your nine wins.

If you play the ace, you win the trick but waste an honour. If you play the three, declarer may win cheaply with the seven or eight. The Rule tells you declarer has only one higher card, so the nine is a strong play. Even if declarer wins with the king, your ace is still in your hand to take a later trick. You have lost nothing.

Using It as Third Hand

When partner leads a low card and dummy plays low, apply the rule before you touch a card. The count is most useful when you are third hand, because you can see dummy's cards and your own, and you know the led card.

Here is a simple routine:

1. Note the card partner led. Is it likely to be fourth highest?
2. Subtract its value from 11.
3. Count the cards higher than the led card in dummy and in your hand.
4. The difference is how many higher cards declarer holds.
5. Choose your card with that number in mind. Can your card win outright? Will it force declarer to spend an honour? Does it keep your own honours intact for later?

If the remainder is zero, declarer has no card higher than the led card. Any card you play above the led card will win the trick. If the remainder is one, declarer has one higher card. You can often play a card that either wins or forces that card out. The bidding will usually tell you whether declarer's single higher card is likely to be an honour or a spot card.

When the Rule of Eleven Misleads

The rule is only as good as the lead. It depends on partner leading fourth highest. If partner leads from a doubleton, a three-card suit, or the top of a sequence, the count is meaningless. You may still be able to work out the position, but you cannot trust the arithmetic.

If partner leads an honour, the rule is less useful, though you can still subtract. If dummy plays an honour, include that card in your count. The rule still works, but you must adjust for the card that has been played.

Signals and suit preference can override the count. If partner's lead suggests they want a switch, or if their carding says they hold a specific honour, trust that information as well. The Rule of Eleven is a guide, not a command.

Declarer knows the rule too. They may play a card that makes you think they have fewer higher cards than they do. The count is about the number of higher cards, not which ones. So use the bidding and the play so far to guess which cards declarer is likely to hold.

A Quick Checklist for Defenders

Before you play third hand, run through this list:

• Did partner lead fourth highest? If not, the rule does not apply.
• What is 11 minus the led card?
• How many higher cards can you see in dummy and your own hand?
• How many higher cards does declarer hold?
• Can your card beat declarer's possible cards? Will it force out an honour?
• Does the bidding suggest declarer's higher cards are honours or spot cards?
• Have you checked partner's signals before committing?

Making the Rule of Eleven a Habit

The Rule of Eleven is not a magic trick. It is a habit. Start by using it on every low lead, even in practice. Do the subtraction out loud if it helps. After a few sessions, the arithmetic becomes automatic.

Remember that it tells you how many, not which. That is enough to make better decisions. It will stop you from grabbing an ace when a nine would do, and it will stop you from ducking when you should cover. When the count is clear, you can play with confidence. When it is not, fall back on your judgement and the clues from the bidding.

Defence is hard because you cannot see declarer's hand. The Rule of Eleven gives you a glimpse. Use it well, and you will find that more of your low-card leads turn into tricks for your side.

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