Bidding and conventions
Bergen raises
Bergen raises are a set of responses to a major-suit opening that show four-card support and a point range in one bid. With four spades and 5 points opposite a 1♠ opening, you jump to 3♠, because nine trumps between you make the three level safe.
Why the weak hand jumps to three
The Law of Total Tricks says it's safe to compete to the level of your combined trump length: eight trumps between the two hands means the two level, nine means the three level, ten means four.
Partner has promised five and you hold four. That makes nine, so the three level is safe whether you hold 4 points or 10.
If the contract fails, the opponents almost certainly had a contract of their own that was making.
4 points. A raise to 2♠ invites the opponents in at the two level; 3♠ makes them start at four.
The preemptive raise is the Bergen bid that gains most often. It takes bidding room away from opponents who probably hold most of the strength.
What each bid does
The full structure, once four-card support is shown by a Bergen bid and three-card support by everything else:
- Two of the major: 6–10 points, exactly three trumps.
- 3♣: 7–10, four trumps. Opener passes with a minimum or bids game.
- 3♦: 10–12, four trumps. A real invitation.
- Three of the major: 0–6, four trumps. Opener bids game or passes. Don't treat it as an invitation.
- 2NT: Jacoby 2NT: 13+ with four trumps, forcing to game.
- A double jump in a new suit: a splinter: game values, four trumps, shortage there.
| West | North | East | South |
|---|---|---|---|
| 1♠ | |||
| Pass | 3♦ | Pass | 4♠ |
| Pass | Pass | Pass |
The partnership gets to send trump length and strength as separate messages.
In standard methods a raise to 2♠ might be three trumps or four, and opener has to guess which in any competitive decision that follows.
Reverse Bergen
Many partnerships swap the two artificial bids: 3♣ becomes the limit raise and 3♦ the constructive one.
The idea is that the limit raise is the hand where the auction continues, so it should take the least room. That leaves 3♦ free for opener to ask questions below three of the major.
The gain is small, and the two versions give the same bids opposite meanings. Write down which one you play.
When it applies, and when it does not
- Only over a major. After a minor opening, 3♣ and 3♦ keep their natural meanings.
- Only by an unpassed hand, in most partnerships. A passed hand uses Drury instead, which solves a different problem in the same auction.
- Only without interference. If the opponents overcall, normal competitive methods apply.
- Only with four trumps. Opener relies on the trump count being exact, and a Bergen raise on three cards misleads every later decision.
What it costs
You give up the natural jump shift into 3♣ and 3♦. That's a small loss: a hand with a strong minor and no support can show it in other ways.
The larger cost is information. Every Bergen bid announces your exact trump length to the defenders before the opening lead.
They know the suit breaks 5-4, on the hands where you stopped in a partscore as well as the ones where you reached game. Standard methods leave the defenders to work that out for themselves.
Strong partnerships are split on Bergen. The preemptive raise is worth a lot. The two artificial bids give away information in return for accuracy, and good players disagree about whether that's a good trade.
If you remember three things
- Four trumps is the entry condition. Three trumps means an ordinary raise.
- Nine trumps belong at the three level whatever your point count.
- Agree Bergen or Reverse Bergen in writing. They are exact opposites.