Cappelletti (Hamilton): Defense to 1NT Openings

Cappelletti is one of the most popular defenses to 1NT openings. When opponents open 1NT, you need a way to compete without getting destroyed. Cappelletti gives you a structured system to show one-suited and two-suited hands while keeping you relatively safe.

The convention is also called Hamilton (same convention, different name depending on where you learned it). Mike Cappelletti popularized it in the 1970s, and it’s been standard in American club bridge ever since.

The core idea: 2♣ shows any one-suited hand. All other two-level bids show two-suiters. This lets you describe your hand type immediately while competing for the contract.

Basic Structure

After opponents open 1NT:

2♣ = One-suited hand (any suit, 10+ HCP or good distribution)

2♦ = Both majors (at least 5-4)

2♥ = Hearts and a minor (at least 5-4)

2♠ = Spades and a minor (at least 5-4)

Double = Penalty (14+ HCP, balanced or good suit)

2NT = Both minors (at least 5-5)

Notice that 2♣ is artificial. You’re not showing clubs. You’re showing a one-suited hand, and partner will ask which suit.

The One-Suited Sequence (2♣)

When you bid 2♣ to show a one-suiter, partner bids 2♦ to ask which suit.

Your rebids:

2♥ = Hearts
2♠ = Spades
3♣ = Clubs
3♦ = Diamonds

Example:

(1NT) - 2<span style="color:#000000;">♣</span> - (Pass) - 2<span style="color:#CC0000;">♦</span>
(Pass) - 2<span style="color:#CC0000;">♥</span>

You showed hearts.

Partner will usually pass your suit. With extreme distribution or a great fit, they might raise.

What hands qualify for 2♣?

After RHO opens 1NT, you hold:
<span style="color:#000000;">♠</span> KQJ1065
<span style="color:#CC0000;">♥</span> 84
<span style="color:#CC0000;">♦</span> A73
<span style="color:#000000;">♣</span> 62

Bid 2♣. Partner will bid 2♦, and you’ll bid 2♠.

You have a six-card spade suit with 10 HCP. You want to compete, and 2♠ should be safe.

The Two-Suited Bids

2♦ = Both majors

This is your most common two-suited overcall. You have at least 5-4 in the majors (preferably 5-5) and want to compete.

After RHO opens 1NT, you hold:
<span style="color:#000000;">♠</span> KJ1065
<span style="color:#CC0000;">♥</span> AQ974
<span style="color:#CC0000;">♦</span> 7
<span style="color:#000000;">♣</span> 84

Bid 2♦. You have both majors. Partner will choose which one to play based on their length.

Partner’s responses:

2♥ = Preference for hearts (or equal length)
2♠ = Preference for spades
3♥/3♠ = Invitational values with good fit
4♥/4♠ = Game with four-card support and distribution

2♥ = Hearts and a minor

You have at least five hearts and four cards in a minor suit.

After RHO opens 1NT, you hold:
<span style="color:#000000;">♠</span> 4
<span style="color:#CC0000;">♥</span> KQ1074
<span style="color:#CC0000;">♦</span> A8
<span style="color:#000000;">♣</span> J9653

Bid 2♥. You have hearts and clubs.

Partner will usually pass 2♥. With heart shortness and length in the minors, they can bid 2NT to ask which minor, and you’ll bid 3♣ or 3♦.

2♠ = Spades and a minor

Same as hearts and a minor, but your major is spades.

After RHO opens 1NT, you hold:
<span style="color:#000000;">♠</span> AJ9654
<span style="color:#CC0000;">♥</span> 7
<span style="color:#CC0000;">♦</span> KQ1063
<span style="color:#000000;">♣</span> 4

Bid 2♠. You have spades and diamonds.

Partner will pass 2♠ with two or more spades. With spade shortness, they can bid 2NT to ask your minor.

Responses to Cappelletti

As responder, your job is simple: pick the best spot.

After 2♣ (one-suiter):

Bid 2♦ to ask. Partner will show their suit. Pass unless you have a great fit and want to invite or bid game.

After 2♦ (both majors):

Pick your better major. With equal length, bid 2♥ (partner might be 5-5 or 5-4 with five hearts).

Raise to 3♥/3♠ with invitational values (10-11 points) and four-card support.

Jump to 4♥/4♠ with game values and great fit.

After 2♥/2♠ (major and minor):

Pass with tolerance for the major.

Bid 2NT to ask for the minor if you have shortness in their major and length in the minors.

When to Compete

Don’t compete with every hand. You need enough shape or strength to make it worthwhile.

Good hands to overcall:

10+ HCP with a six-card suit
8+ HCP with a 5-5 two-suiter
Great shape with 7+ cards in your suits

Don’t overcall with:

Balanced 10-11 HCP (just pass)
Weak suits (QJxxx and Jxxxx is not worth it)
Vulnerable at unfavorable colors

Example of passing:

After RHO opens 1NT, you hold:
<span style="color:#000000;">♠</span> QJ863
<span style="color:#CC0000;">♥</span> 74
<span style="color:#CC0000;">♦</span> AJ4
<span style="color:#000000;">♣</span> K95

Pass. Your spade suit is weak, you’re balanced, and you have 11 HCP. You’re not strong enough to double for penalty, and 2♣ followed by 2♠ on this junk suit is asking for trouble.

Common Mistakes

1. Bidding 2♣ with clubs

You have six clubs and think 2♣ shows clubs. It doesn’t. 2♣ is artificial.

When partner bids 2♦ to ask, you’ll bid 3♣ to show your clubs. You have to go to the three level.

2. Using Cappelletti with 4-4 in the majors

You need at least 5-4 to compete. With 4-4 in the majors, pass. You don’t have enough shape to risk the three level if partner has a doubleton in both majors.

3. Forgetting about vulnerability

At favorable vulnerability (not vul vs vul), you can stretch. At unfavorable (vul vs not vul), be disciplined.

Getting doubled in 2♠ down three for -800 when they were making 3NT for +400 is a disaster.

4. Bidding 2NT with weak minors

2NT shows both minors, but you need at least 5-5 and decent suits. Don’t bid 2NT with 54 in the minors or with xxxxx and xxxx.

Partner will pick a minor and pass. If your suits are terrible, you’ll go down a lot.

Advanced: Judgment Calls

Sometimes you have a close decision between overcalling and passing.

Example 1:

After RHO opens 1NT, you hold:
<span style="color:#000000;">♠</span> AJ10765
<span style="color:#CC0000;">♥</span> K4
<span style="color:#CC0000;">♦</span> J63
<span style="color:#000000;">♣</span> 82

Bid 2♣ (then 2♠). You have a good six-card spade suit. Even if partner has a doubleton, 2♠ should be safe, and you might push them to 3NT when they were going to stop in 2NT.

Example 2:

After RHO opens 1NT, you hold:
<span style="color:#000000;">♠</span> K4
<span style="color:#CC0000;">♥</span> QJ965
<span style="color:#CC0000;">♦</span> 73
<span style="color:#000000;">♣</span> AJ82

Pass. You only have five hearts, your suit is mediocre, and you have balanced values. Competing here is asking to get doubled and go down.

Example 3:

After RHO opens 1NT, you hold:
<span style="color:#000000;">♠</span> KQJ106
<span style="color:#CC0000;">♥</span> AJ1095
<span style="color:#CC0000;">♦</span> 7
<span style="color:#000000;">♣</span> 84

Bid 2♦. You have both majors, 5-5 shape, and good texture. Even if partner has a doubleton in both, one of your suits should play okay.

Cappelletti vs Other Defenses

Cappelletti pros:

Shows one-suiters and two-suiters clearly
Gets majors in quickly (2♦ for both majors is low)
Partner always knows your shape

Cappelletti cons:

2♣ then 3♣/3♦ gets you high with minor suits
You can’t show clubs or diamonds at the two level
Less flexible than DONT

vs DONT: DONT (Disturbing Opponents Notrump) uses double for a one-suiter and two-level bids for two-suiters starting with that suit. Some prefer it. Both work.

vs Landy: Landy uses 2♣ for both majors. Simpler but less flexible.

vs Multi-Landy: Multi-Landy is like Cappelletti but with different meanings. Close relative.

Why Cappelletti Matters

When opponents open 1NT, they have 15-17 HCP. That’s a lot. But they don’t have game sewn up, and they might not have the best spot.

If you have shape, you can compete. Maybe you push them too high. Maybe you find your own making contract. Maybe partner has a fit and you steal the hand.

Cappelletti gives you the tools to compete safely. It’s structured, it’s clear, and partner always knows what you have.

Compare this to overcalling naturally:

Without Cappelletti:

(1NT) - 2<span style="color:#000000;">♠</span>

Is this one-suited or two-suited? Strong or weak? Partner doesn’t know.

With Cappelletti:

(1NT) - 2<span style="color:#000000;">♣</span> - (Pass) - 2<span style="color:#CC0000;">♦</span>
(Pass) - 2<span style="color:#000000;">♠</span>

Partner knows you have a one-suited hand with spades. No ambiguity.

You’ll face 1NT openings constantly. Having a good defense to 1NT means you won’t sit there and watch opponents cruise to 3NT when you had a making 2♠ contract.

Learn Cappelletti. Use it. Compete when you have shape. Your game will improve.