The Mini Splinter convention is applied with singleton or void when a partner opens 1♥ or 1♠:

• • • 9+ HCP if there is a balance for two in the opening suit;

    • 8+ HCP if there is a balance of three in the opening suit;

    • 7+ HCP if there is a balance of four in the opening suit.

HCP of the short suit are not counted.

The use of the Mini Splinter convention requires:

• • • exclusion of the Bergen convention;

    • use of the Support 2NT convention with with 3 cards support and no upper limit.

Answers after 1♥: 

• • • 2NT - Support 2NT;

    • 3♣ - singleton ♣;

    • 3♦ - singleton ♦.

Answers after 1♠: 

• • • 3♣ - singleton ♣;

    • 3♦ - singleton ♦;

    • 3♥ - singleton ♥.

Opener rebid after non-2NT bids:

• • • return to the agreed suit - from the balance sheet no more than 3 in the opening suit;

    • 3NT - positive, at most five in the opening suit;

Responder bid:

• • • • • 4♣ - 12+ HCP;

        • 4♦ - 10-11 HCP;

        • 4 in the suit of the opening - 8-9 HCP.

    • 4 in the suit of the opening - six in the suit of the opening;

    • another bid - slam aspirations.

After suit or NT intervention, the convention is off.

The application of the convention causes a significant increase in the frequency of Support 2NT in the responder and the large splinter in the opener.