The rule of 11 says: when partner leads a fourth-best card, subtract its rank from 11. The answer is the number of cards higher than the card led held by the other three hands: dummy, you and declarer. Subtract the higher cards you see in dummy and in your own hand, and you know how many declarer holds.
It works with any system: it depends only on your lead agreement, fourth best from length, which is standard in Standard American, 2/1 and Acol. The arithmetic takes five seconds and often tells you exactly which card to play at trick one.
How the Rule of 11 Works
Why 11? Count the cards above any spot. Above the 6 are eight cards: 7, 8, 9, 10, J, Q, K, A. In general a card of rank r has 14 - r cards above it (the ace counts as 14). If partner leads fourth best, partner holds exactly three of those higher cards. So the other three hands hold 14 - r - 3 = 11 - r.
The procedure for third hand:
- Subtract the card led from 11.
- Subtract the higher cards you can see in dummy.
- Subtract the higher cards in your own hand.
- What is left is declarer's count of cards above the lead.
| Card led | 11 minus card | Cards above it in the other three hands |
|---|---|---|
| 7 | 11 - 7 | 4 |
| 6 | 11 - 6 | 5 |
| 5 | 11 - 5 | 6 |
| 4 | 11 - 4 | 7 |
The rule is most useful when the lead is a middle spot (5 to 8). With a low lead such as the 2 or 3, the count is large and tells you less.
A Worked Example
West opens 1NT and East raises to 3NT. North, your partner, leads the ♥6.
West declares 3NT; East is dummy. Partner (North) leads the ♥6, fourth best. You are South, third hand. Reveal the deal after you decide.
Partner leads the ♥6 and dummy shows ♥K102. Do the count: 11 - 6 = 5 hearts above the six outside partner's hand. Dummy holds two of them (the K and 10), you hold three (the A, J and 9). That is all five. Declarer has no heart higher than the six.
Now the play is easy:
- If dummy plays the ♥2, you win with the ♥9. Nothing of declarer's can beat it.
- If dummy plays the ♥10, cover with the ♥J, the cheapest card that wins.
- If dummy plays the ♥K, win the ♥A.
Without the rule, many players grab the ace at trick one "to be safe". The rule shows that the cheap 9 does the same job and keeps your ♥A and ♥J sitting over dummy's ♥K and ♥10.
The rule also tells you about partner's suit. The cards above the six are the A, K, Q, J, 10, 9, 8 and 7. You see the A, K, J, 10 and 9, and declarer has none, so partner holds the ♥Q87 above the six, plus the six, and one more low card if the lead was from five.
What Third Hand Concludes
The final number tells you more than which card to play:
- Zero for declarer: you can win cheaply, and partner's suit is ready to run once dummy's honors are gone.
- One for declarer: list the higher cards you cannot see. One of them is with declarer, the rest with partner, and declarer's play to the trick often tells you which.
- Two or more: declarer has real stoppers. Think about switching once you see the rest of dummy.
- A negative number or an impossible count: the lead was not fourth best. It is probably a short suit or top of a sequence.
TipDo the count before dummy's card is played to trick one. If you wait until it is your turn, you will be thinking while everyone watches, and that hesitation can pass information. Plan, then play in tempo.
Declarer Can Use It Too
Declarer sees dummy and his own hand, so the same subtraction tells declarer how many higher cards third hand holds. Say West leads the ♠7 against your 3NT, and you hold ♠A94 with ♠Q105 in dummy. 11 - 7 = 4 higher cards outside the leader. You see the A, 9, Q and 10. Third hand has none above the seven.
So you can play the ♠5 from dummy and win cheaply with the 9 in hand, keeping the ♠AQ10 for later. Declarer often wins an extra trick or an extra stopper from this one subtraction.
The Rules of 10 and 12
Some partnerships lead third and fifth best instead of fourth best: third from a three- or four-card suit, fifth from a five-card or longer suit. The same arithmetic still works with a different number:
| Lead style | Higher cards in the leader's hand | Rule |
|---|---|---|
| Fourth best | 3 | Rule of 11 |
| Third best | 2 | Rule of 12 |
| Fifth best | 4 | Rule of 10 |
The catch: third hand often does not know whether a third-and-fifth lead is from four or five cards, so you work out both answers. They differ by two, and the rest of the deal usually tells you which is right.
When the Rule Fails
The rule is only as good as the lead agreement. It does not apply when:
- The lead is top of a sequence (K from KQJ, Q from QJ10). Honor leads are not fourth best.
- The lead is from a short suit: top of a doubleton, a singleton, or top of nothing from three small. Against suits, these leads are common. See MUD leads for one method with three small cards.
- The leader has a choice of fourth best: from a holding like 9 8 7 6, many players lead the 9 or 8, which looks like a high spot.
- Partner's suit is long and the count gets large: with a low lead the rule says "many higher cards", which you already knew.
Declarer can also hide cards by playing a higher spot, but declarer cannot change the count. If the rule says declarer holds one higher card, declarer holds one: the false card only hides which one.
Practice: The Rule of 11
West declares 3NT. Partner (North) leads the ♠7, fourth best.
Partner leads the ♠7 against 3NT. Dummy (East) holds ♠Q103 and plays the ♠3. You hold ♠K94. Which card do you play?
Your hand:
The rule of 11 is a habit, and habits come from repetition. BridgeDummy's Lead Gym lets the robots bid a random deal and then shows how every opening lead scores, so you see fourth-best leads in action from the leader's seat. The lead puzzles test the same choices over many deals that fit the auction. For more on defense, read the rule of 7, bridge signals, opening leads and second hand low, third hand high.