4th Suit Forcing (4SF)
by Steve Turner1
Premise: A way for responder to create a forcing
auction, at the 2nd turn to bid, when no natural sequence exists to do
so (for example, jump rebids by responder either in opener's 1st bid
suit or in responder's 1st bid suit are invitational (i.e., NOT
FORCING), thereby creating the need to generate a sequence which IS
forcing to opener). The treatment about to be discussed bears a strong
resemblance to "New Minor", with some very important differences.
A typical "4th suit forcing" format is the following: 1-1-1-2 or 1-1-2-2, where the 4th suit is
artifical, at least invitational,
requesting descriptive "prioritized" rebids from opener:
- simple raise of responder's 1st bid suit with 3-card support and
- jump raise of responder's 1st bid suit with 3-card support and a
- 2NT with the 4th suit stopped, lacking either of the above,
likely doubleton w/opener's 1st bid suit, but a singleton sometimes.
- raise the 4th suit with 4-card support.
- make the most natural rebid possible, lacking any of the above.
Opener's Response to the Fourth Suit
First, some example hands will demonstrate how opener responds to a 4th
suit sequence by responder. Each example below shows opener's hand,
auction with 1
(except d: 1).
|Answer: 2 or 3
Variations in Agreements
|Std version of 4SF
||Game force (4SFG)
|Hardy version of 4SF
||Game force, unless responder rebids the 4th suit
(always lower ranking and constructive to invitational, roughly 8+ to
|Mod version of 4SF
||A rebid of 2NT by either opener or responder can
be passed and the Hardy version rule applies as well
If you agree to use the Std version, ALL rebids after 4SF are game
forcing. No exceptions. Therefore, you need to discuss this treatment
(used by many partnerships) if you agree to 4SFG.
If you agree to the Hardy version, the following type of auction in
(typically x AJ10xx KJxxxx x). Had responder held 6 hearts and 5
diamonds instead, same strength, a 2
rebid is more reasonable (instead of 4th suit), almost always promising
a 6-card suit, non-forcing.
If you agree to the Mod version, the following type of auction can
This allows for invitational misfits. If responder picks up, for
example: Qx A10xxx
, wouldn't it be nice to stop in 2NT? Does responder have any
intelligent choice other than 4SF (2)
after opener's rebid? Opener could easily have any one of several hands
that should play in no higher than 2NT. Refer to hands c), j) and
Responder's Use of Fourth Suit with Strong Hands
Now for some responder hands, after a 1
opening, followed by a rebid of 1:
With a), does responder have a bid other then 4SF (2) at
the next turn to bid? Responders rebid of 3,
after opener rebids, shows a game force with good club support.
Remember, any suit bid by responder at the 3-level, following 4SF, is
still forcing, EXCEPT a rebid of the 4th suit.
With b), the hand is too good to jump to 4 at
responder's 2nd turn to bid. Slam is a strong possibility, so it's time
to explore. Voila - 4SF, followed by a raise later. Opener will know
that we have a slam try here (since responder neither invited (jump to 3) nor
jumped to game directly). The 4SF temporizing bid, followed by a raise,
shows this type of hand.
With c), responder uses 4SF, followed by hearts (showing 6 and a
game force). Very descriptive and allows for co-operation from opener
to find the best spot.
When considering a gadget, given a choice between it and another,
the decision usually gets down to frequency of occurrence.
There is very little doubt that 4SF is superior to the old-time
standard methods, due to the non-guesswork to land on your feet, with
little cost on the majority of hands. The real decision (and perhaps
the jury is still out on frequency) is "which treatment" of 4SF to
Caveat for 2/1 System bidders:
The auction 1(minor)-1-1-3(other
minor) describes a hand which contains a very good 6-card suit and 4 of
the major, invitational strength. Does this treatment sound familiar?
The "new minor" variation is similar, 'tho the hand strength range
promises the upper end with the 4th suit approach. With "new minor",
opener's hand promised to be balanced with a 1NT rebid; therefore, a
jump to 3 of the other minor after a 1NT rebid can be made on lesser
values and some latitude on suit strength. The partnership is
guaranteed at least an 8-card fit in the new minor, and safety is more
likely. Thus, without a 1NT rebid, and a distributional misfit a
possibility, a strong suit and invitational values is a sensible
This auction does not really apply to SAYC bidders, since the other
minor (1-2 or 1-1) can
be bid immediately (unless you have a strict agreement that responder
must bid a 4-card major instead of a 6-card minor with less than game
values - if you do, you might consider the alternative approach).
1See the following primary reference for
Max Hardy (1989) Two Over One Game Force. Published by Max
Hardy, Las Vegas, Nevada.