Cappelletti convention

Cappelletti (also called Hamilton and Pottage) is a bridge bidding convention for the card game contract bridge, primarily used to interfere over opponent's one notrump (1NT) opening. Usually attributed to Michael Cappelletti and his longtime partner Edwin Lewis, origin of the concept is also claimed by Fred Hamilton, John Pottage and Gerald Helms.

Cappelletti is a defensive bidding convention particularly recommended for use against a weak 1NT opening (12-14 HCP) but can also be used against stronger 1NT openings (15-17 HCP).

The High Card Points (HCP) range for Cappelletti overcalls is 9-14 points.

It's strength is that where possible it shows partner a choice of multiple suits for the overcall.

Over the 1NT opening, the over-calling opponent makes one of the following bids to indicate a one-suited or a two-suited hand:-

With 15 or more points, a Double for penalties by Intervener is recommended instead of Cappelletti over the 1NT opening; (generally showing values equivalent to a strong 1NT opening, i.e. 15-17 or 16-18 points by partnership agreement).

The power of this convention, rather than making a simple overcall, comes from its focus on showing two suited hands to partner and finding the best partnership fit between those two suits. Remember all 'conventional' bids and 'conventional' responses need to be alerted!

After first seat opens with 1NT, the opposition may wish to indicate a hand worthy of an overcall; (a Cappelletti overcall is most usually made from second seat but if second and third seat pass, then fourth seat can also intervene with Cappelletti. Bearing in mind second seat has already passed, fourth seat would want their holding to be towards the upper end of the Cappelletti points range in order to make such a call).

Over the 1NT opening, the over-calling opponent (known as 'Intervener') makes one of the following artificial bids to indicate a one-suited or a two-suited hand:

With a strong hand of his own, (14+ HCP) Advancer may think that the defensive partnership could have the possibility of a game call themselves.

To explore this possibility, any bid by Advancer beyond the natural conclusion of the Intervener calls described above, is invitational to game.
Such a bid shows most importantly the High Card Points range in Advancer's holding (which should be 14+ HCP; - at weakest, Intervener has promised only 9 HCPs, and since bidding is now advancing to the 3-level, 14 HCP in advancer's hand guarantees a minimum joint holding of 23 HCP for the partnership!).

(Note that, before extending the bidding in this way, Advancer should consider that if he makes a 3-level bid in a suit ranking above the 'Cappelletti' suit, then there may be no exit to bidding short of a Game Call anyway; - consider if you will be forcing a de facto game call by advancing the bidding in this way, and what are the probabilities of the partnership holding supporting this?).

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