2-over-1 Bidding System

Introduction

Basic principles and definitions    

2-over-1 variations

Responder's first bid

Raising partner's major

Follow-up auctions -- meanings of opener's and responder's later rebids

Guidelines for cuebidding and ace-asking

Forcing Notrump convention  (separate document)

Introduction

One of the most popular bidding systems in the U.S. is the 2-over-1 Forcing-to-Game system. It's based on Standard American with 5-card majors. The main difference is in the meanings of 2-level responses to a major-suit opening.

The general approach is just as the name suggests: If responder's first bid is 2 of a new suit (1S by opener - 2C, 2D or 2H by responder), it sets up a forcing auction; the partnership must bid on to game level. This is different from old-fashioned Standard American, where a 2-level response promises a good 10+ points, but it is not forcing to game.

The main advantage with this system is that it saves bidding room. After making the initial 2-level response, responder doesn't have to jump to show forcing-to-game values. Because the auction can stay low, opener and responder have more room to exchange information below game level.

One of the disadvantages is that there's no easy way to show many invitational hands of 10-11 pts. To describe these hands, you must use the Forcing Notrump convention, which is a key part of the system.

The 2-over-1 system is more complex than it may seem. Even though the basic principle sounds fairly straightforward, the auctions can become quite complicated, especially when you're investigating slam possibilities. Forcing Notrump auctions can also be difficult unless you have a clear understanding of all the possible follow-ups.

The summary below is intended as a basic introduction to 2-over-1 agreements. There's much more to the system than can be covered here, so if you're serious about learning its finer points, you'll probably want to consult other resources. Here are some recommended books and software packages that offer more detailed analysis:

25 Steps to Learning 2-over-1 by Paul Thurston

Workbook on the Two-Over-One System by Mike Lawrence

Two-over-One Game Force by Max Hardy

Standard Bridge Bidding for the 21st Century by Max Hardy

Understanding 1NT  Forcing by Marty Bergen

Interactive CD software:  Two-Over-One System by Mike Lawrence

Basic 2-over-1 principles and definitions

2-over-1 forcing-to-game is "on" only when your side opens 1H or 1S in 1st or 2nd seat and the next player passes and responder makes a non-jump bid of 2 of a new suit. The only relevant auctions are:
       1-2     1-2    1-2     1-2    1-2

2-over-1 meanings are "off" when:

Game level is defined as 3NT or 4 of a suit. If your trump suit is a major, the "4-of-a-suit" agreement will get you to game. Note, though, that if your trump suit is a minor, you are not forced all the way to 5C or 5D. Even if you've made a 2-over-1 response, your auction can end at 4C or 4D if that's your agreed suit.

A 2-over-1 response is just one of the ways you can show game values. You do not have to make a 2-over-1 with all game-forcing hands.

Playing the 2-over-1 system does not affect the meanings of other auctions. One-level responses (1H-1S) and direct raises of partner's suit (single, limit and forcing) have the same meanings as in standard bidding. Other conventions and treatments -- strong or weak jump shifts, Bergen raises, Jacoby 2NT, splinter bids, New Minor Forcing, etc. -- can be included in your 2-over-1 system with no modifications.

2-over-1 variations

There are several ways to structure your 2-over-1 system. The most widely used approaches are the systems proposed by bridge writers Mike Lawrence and Max Hardy. The two systems are similar, but they differ in the meanings of some of opener's rebids. The Lawrence system also makes more exceptions to the always-forcing-to-game rule. The summary here is based largely on the Lawrence approach.

Questions to ask your 2-over-1 partner:

Responder’s first bid

Your priorities for your first response:

First:  Make the appropriate raise of partner's major if you have 4-card support (single, limit or forcing raise) OR  3-card support with 5-10 pts. (single raise). The only supporting hand that will not make an immediate raise is one with 3-card support and a good 10+ pts. See Raising partner's major below for more details on how to show all types of supporting hands. 

Second:  If you don't have a supporting hand, show a 4-card spade suit (respond 1S to a 1H opening).

Third:  If you have game-forcing values, bid a new suit at the 2-level. "Game forcing" is usually 12+ points, but it should be interpreted as any hand that you would have opened or that's worth 12+ pts. because of a fit for partner's suit. After partner opens 1 of a major suit:
     A 2C or 2D response shows a 4+-card suit. In rare cases, though, 2C may be a 3-card suit.
     A 2H response (1S-2H) promises a 5+-card suit.
If you play Lawrence-style 2-over-1, you can bid 2 of a minor if you have 10-11 pts. and a 6+-card suit.

Fourth:  With all other hands (5-11 pts. without support OR 10-11 pts. with 3-card support), bid the Forcing Notrump.

Raising partner’s major

Here's a summary of your bidding options when you have 3+-card support for partner's opening bid of 1H or 1S.

With a balanced hand:

With an unbalanced hand (singleton or void):

Follow-up auctions

Opener’s second bid: 

One of the common misconceptions about 2-over-1 auctions is that after the forcing-to-game response, neither partner has to jump to show extra values. This is only half right. The general guideline is that responder does not jump with strong hands, but opener does.

In most 2-over-1 auctions, responder is the "captain" because he has more information about opener's hand than opener has about his. When responder has a strong hand, he chooses forcing, low-level rebids to give opener maximum room to provide information. Responder tends to be the "asker" and opener is the "teller". 

If opener bids weak and strong hands the same way, responder will never be able to make an intelligent decision about how high to bid. For this reason, it's important for opener to communicate his strength as early as possible in the auction. To do this, opener makes value bids that show whether or not he has a minimum hand -- he bids less with less, and more with more.

Suppose, for example, that you open 1S with AKJ1087 A62 KJ8 7 and partner responds 2C. If you follow the "never-jump" rule and rebid just 2S, you've kept the auction low, but you've concealed your strength. It's worth using up an extra level of bidding if it accurately describes your hand, so you should make the value bid (3S) with this hand.

Note, though, that you can take advantage of the low-level rebid when you have a hard-to-describe hand such as  AJ6543 AK2 KJ8 7. Since you don't want to over-emphasize such a weak spade suit, you can rebid 2S with this hand and then show your extra values later. 

After 1H by you – 2D by partner, here are the meanings for your second bid:

Responder’s second bid: 

Responder goes "slow" when he has extra values; he uses fast-arrival bids when he has a minimum. A low-level rebid in opener's suit (slow -- 1S-2C-2NT-3S) suggests extra values (14+ pts.) and gives opener more room to describe his hand. A jump to game in opener's suit (fast -- 1S-2C-2NT-4S) shows a minimum (12-13 pts.) with no interest in slam. 

After 1H by partner – 2D by you – 2H by partner, the meanings of your second bid are:

Opener’s third bid:

If responder has made a bid that asks for more information (1H – 2D – 2H – 2S, 2NT or 3C), he denies 3+-card support for your suit. He often needs to know more about your hand to choose the contract. To provide this information, you can:

If partner's second bid was a low-level raise of your suit (1H – 2C – 2H – 3H), he's showing a "good" 2-over-1 with 3-card support and at least mild interest in a slam. You can:

Guidelines for cuebidding and ace-asking