Cappelletti Convention: Defense to 1NT Explained

Cappelletti is a defense to the opponents' 1NT opening in which double is for penalty, 2♣ shows any one-suited hand, 2♦ shows both majors, 2♥ and 2♠ show that major plus a minor, and 2NT shows both minors. It lets you compete with every common shape while keeping the penalty double for strong hands.

The convention is named after Mike Cappelletti; in parts of the world the same structure is called Hamilton, after Fred Hamilton. It is one of the most widely played defenses to 1NT in North American club and tournament bridge, usually against a strong (15-17) notrump.

After the opponents open 1NT, you (the player in the direct seat or the balancing seat) can use:

Strength. In the direct seat, against a strong notrump, about 10+ HCP or a hand with very good shape. Vulnerability matters more than points: when you are vulnerable, keep good suits. In the balancing seat (1NT P P), you can be lighter because responder's pass shows a weak hand, so partner rates to hold some values.

• 2♦: the relay. Overcaller passes with diamonds or bids the long suit: 2♥, 2♠, or 3♣ with clubs.
• Pass: you hold long clubs and a weak hand, and you are happy to play 2♣ in case partner's suit is clubs. It is a gamble that sometimes works.
• 2♥ or 2♠: your own long suit (six cards), to play. Partner passes unless partner's suit is a strong one.
• 2NT: invitational or better, asks partner to describe the suit and strength.

• 2♥ or 2♠: to play. With equal length, choose hearts (the cheaper suit) so that partner can correct to 2♠ with five spades.
• 3♥ or 3♠: invitational with a fit.
• 4♥ or 4♠: to play.
• 2NT: asks for more: partner shows shape and strength.
• Pass: rare, long diamonds and a weak hand.

• Pass: you have tolerance for the major.
• 2NT: asks for the minor. Overcaller bids 3♣ or 3♦.
• Raise: invitational or competitive with three or more trumps.
• 3♣: pass or correct: you prefer partner's minor.

• 3♣ or 3♦: choose a minor.
• 4♣ / 4♦ / 5♣ / 5♦: to play with a fit, at the right level for your trumps.

East opens a strong 1NT. You hold ♠4 ♥KQJ93 ♦AJ1074 ♣85: 11 HCP, five-five in hearts and diamonds. Bid 2♥: hearts and a minor.

Partner has two hearts but four diamonds, so 2NT asks for your minor. You show diamonds and partner passes 3♦.

Double dummy, 3♦ makes exactly: +110. East-West hold 23 HCP and a spade fit; left alone, they make 140 in spades and even 3NT. West might still compete with 3♠, but now East-West must guess at the three level.

More hands over a strong 1NT:

• ♠KQ1083 ♥AJ84 ♦72 ♣95: 2♦, both majors.
• ♠73 ♥52 ♦KQJ1084 ♣A62: 2♣, then pass partner's 2♦ relay.
• ♠6 ♥J7 ♦KQ984 ♣AQJ73: 2NT, both minors.
• ♠AQ5 ♥KJ10 ♦AK93 ♣Q104: double, 19 HCP, for penalty.

Vulnerability. Vulnerable against not vulnerable, a two-level bid that is doubled can cost 500 or 800. Keep good suits.

Suit quality. A one-suited 2♣ bid with ♥976532 is a poor risk: your suit takes few tricks and partner's relay pushes you higher. The best Cappelletti hands have strong suits.

The penalty double. Against a strong notrump, a penalty double with 15-16 HCP may not beat 1NT if the strength is split. A long running suit, such as ♦AKQJ75 with an outside entry, is often a better penalty double than a balanced 16.

Variations.

• Hamilton is the same convention under another name.
• Some pairs change the meaning of 2♣, for example to clubs and a higher suit, borrowing an idea from DONT.
• Some pairs play Cappelletti only in the direct seat and natural bids in the balancing seat.
• Against a weak notrump (12-14), many pairs prefer Landy or a natural method with the penalty double, because a weak 1NT is often worth doubling.

Each system card has its own defense to 1NT: see what 2♥ means in every system over the opponents' 1NT. Other defenses to compare: DONT, Landy and Meckwell.

(1NT) ?

• X: penalty. Advancer passes, or runs with a weak hand and a long suit.
• 2♣: one suit. 2♦ relay; overcaller passes (diamonds) or bids the suit.
• 2♦: majors. 2♥ / 2♠ to play, 3♥ / 3♠ invite, 2NT asks.
• 2♥: hearts + minor. Pass, raise, or 2NT ask; 3♣ pass or correct.
• 2♠: spades + minor. Same structure.
• 2NT: minors. 3♣ / 3♦ choice, higher to compete.
• 3-level: natural, preemptive.

Competing over 1NT is about risk, and only real hands teach you how much risk is right. BridgeDummy's bidding puzzles place you in South's seat over the opponents' notrump, test each call over many deals that fit the auction, and show you the best answer with sample deals.

For a free check of one board, the double dummy analyzer shows how many tricks each side takes in every strain. It is a quick way to see whether your two-suiter was worth showing.

Related pages: doubles in bridge, notrump in bridge and the Law of Total Tricks.