Conventions in depth
An opening 2♦ that shows a weak two in hearts or spades without saying which.
An ordinary weak two names its suit: open 2♠ and you hold spades. The Multi 2♦ needs a good six-card heart or spade suit and about 5–10 points, the same hand as a weak two. Because the opponents cannot see your suit, they cannot read the auction as easily, and they cannot safely double 2♦ to punish you.
Partner almost always makes the same reply, letting your real suit come to rest as the contract:
| You | Partner |
|---|---|
| 2♦ | 2♥ |
| 2♠ | Pass |
You open 2♦ with a weak hand and long spades. Partner, expecting a major but not knowing which, relays 2♥. You correct to 2♠, your real suit, and partner passes.
When Multi 2♦ is switched on, all your weak-two openings in the majors go through 2♦, which frees the natural 2♥ and 2♠ openings. The cost: a weak two in diamonds no longer has an opening bid (the 2♦ call is reserved for the majors), so BidMaestro passes those hands rather than opening them at the one level.
BidMaestro plays the weak-only Multi 2♦: it always shows a weak two in a major. Many partnerships also include strong hands in the same opening, such as a big balanced hand or a strong three-suiter, and add a 2NT enquiry for a strong responder. BidMaestro does not: the 2♥ relay is the only response it uses. Note too that the Multi 2♦ is restricted in many North American clubs under American Contract Bridge League rules, because it is awkward to defend against.
